Fallcheck time is here – It’s not too late to have your heating system checked

Your heating system runs more at night during cold weather than your cooling system does. It’s always prudent to have your system safety inspection before the cold winter nights arrive.

Electric furnace contactorWe found this Heating Contactor that was outside the normal temperature range. We replaced it and cleared up the problem before it occured. After replacement

These devices handle large current flows. Defective devices can fail and leave you with no heat in the middle of cold weather. Give us a call at 251-990-0998 for your Fallcheck.

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Stains on your ceiling – warped flooring

As I write this on the 16th of October just after noon, the relative humidity outside is 90% with a temperature of 84 degrees F. In the AC business this is known as ‘just right’.

In the past 10 weeks I have visited two or three homes each week to inspect the cause of:

  • mildew around the ceiling registers
  • staining of drywall around ceiling registers
  • warping of hardwood flooring
  • musty odors inside the home
  • reports of high humidity readings on wall thermostats or hygrometers

The reason this involves an air conditioning contractor is that air conditioning is the cause. Or rather, many homes are not constructed properly to exist in this area with air conditioning.

To grasp the problem of the ceiling stains and the warping floor it helps to understand the term dew point. You have seen a glass of cold water sweat on the outside. Dew point is the temperature at which this occurs.

When the French built the first settlement at Mobile in 1700, dwellings may be wooden pikes driven into the ground with mud daub. None of the dwellings constructed of wood lasted more than a few years; everything rotted. This has always been a humid climate so they started building up off the ground on stone or cement piers. Other than the problem of termites this was a durable method of construction.

Pier And Beam House Plans Lovely Pier Footing Detail House Pier Foundation Details pierBefore air conditioning, homes built like these could last for centuries.

Enter Willis Carrier. While the inside of the home is drier, air conditioned homes can chill parts of the building components below the dew point of the ambient air and condense water – the same water that drips on the outside of the glass and puts those rings on your grandmother’s coffee table.

The main purpose of this article is to introduce some concepts that will be developed in future posts:

  • The connection between mildew in the home and relative humidity
  • The control of humidity with the air conditioning system
  • Methods of correcting the symptom
  • How the air conditioning ductwork contributes to mold and mildew
  • Using the air conditioning system to pressurize the conditioned space

mold by window

Mold on wall beside window

The picture above is actually not caused by air conditioning but occurs during the heating season. It is the same process but in reverse. I show it here because it illustrates what happens inside a wall. The mechanism is as follows: This poorly insulated window casing gets cold in the winter chilling the drywall below the dew point of the inside air. A curtain or other internal window covering can trap air against the window cooling the air below the dew point.

Bath fans, electrical openings and attic stairs are openings to the outside air. If the air pressure inside is lower than outside, wet air will be drawn into any openings.

hvac-air-handler-duct-system-pressure-flow-closed-vents-1-resized-600

Since the house pressure is now lower, air will be drawn in to all openings in the building envelope. When this wet, high dew point air contacts cool building surfaces condensation of water vapor into water occurs. This chronic condition is the cause of mildew and mold.

This process also occurs in areas that aren’t visible. One place with a symptom that is visible is warped wood flooring. When wet air is pulled into a wood sub-floor high humidity without condensation can be enough to cause ‘cupping’ of flooring.

lauzon-hardwood-flooring-blog-humidity-cupping-crowning.jpg

Fresh-air-exchange

Pressurizing the home is one method used to use the air conditioner to correct a negatively pressurized home.

Posted in Air Conditioning, Ceiling Stains, Ductwork, Humidity, Mold | Leave a comment

American Standard Nexia Home Automation

Last Christmas my son and daughter-in-law gave us a new Alexa Echo Dot. At first I was concerned that this small device listened in to even whispered conversations. Seeing the little blue circle light up when I said anything close to ‘alexa’ was unnerving at first…

Empire of the Ants

But after a month or so I found myself welcoming my new robot overlord.

Within 15 minutes we had downloaded the Nexia app from Amazon and said, ‘alexa, turn down the kitchen to 70 degrees’ and, bob’s-your-uncle, I heard the air conditioner kick on. Nothing to it.

Let me explain what Nexia is and what is has to do with your heating and cooling system.

Nexia is a system of home automation that uses Z-Wave technology to control devices around your home without the need for communication wires. American Standard thermostats are available with Nexia built-in.

With Nexia installed you are able to control your thermostat from anywhere you have an internet connection, right from your smartphone.

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If you choose to you can link your American Standard system to Swinson Air Conditioning Secure Diagnostic Platform that monitors your system for errors and reports problems to us 24/7.

Nexia Diagnostics

Alert Screen

We can check that everything is ok

Zone Screen

It connects to our room-by-room zoning system to keep every corner of your home just the right temp or turn off unused areas

Runtime History

Lets us see how the system reacts to the outside world.

Think this is overly complex? In the five years since Nexia and our digitally control Platinum systems were introduced they are the most trouble free equipment  that we maintain. Here are some important facts:

  • Out of hundreds of Platinum Air Handlers we have yet to have a blower motor fail. Zero failures so far and that even includes lightning. We process wheelbarrow loads of other brand’s motors under warranty and out of warranty.
  • Two auxiliary heater boards
  • No fan control boards
  • No Electronic Expansion valve boards
  • Two router connection issues for thermostats

Nexia thermostats also come with a manufacturer’s 10 YEAR warranty when purchased with a new system.

So  who cares if Google knows that your living room is 74 degrees. Start enjoying the benefits of Nexia today.

Joan collins

Long live NEXIA!!

 

 

 

 

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Ewwwww!!! Swinson AC has a the only one in captivity

Heating and Air Conditioning systems do several things to the air in your home or office:

  • Cooling
  • Heating
  • Drying
  • Cleaning

When your system is performing the first two items on that list it is easy to notice when it isn’t working. The third, drying the air, is not quite as easy to perceive.

The last item, cleaning, takes effort to discover.

You might notice dirt around the ceiling registers or dust on tabletops and furniture. Maybe you have thought about having your ductwork cleaned.

Generally, of all the dirt and mold to be found in an air conditioning system about 5% by weight (if any) is found in the ductwork. The lions share is found in the air handler or furnace, in the cooling coil and the blower wheel.

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Here is a coil after we took a swipe from the face with a wirebrush

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Here’s the wirebrush

Cleaning the blower wheel is a task that has been designed into most blower systems. It is a nut and bolt removal to the outside for cleaning and re installation. This is not the case with the indoor coil. Up until we built our ‘gadget’ cleaning the indoor coil adequately required:

  • removal of the refrigerant from the system
  • cutting of the refrigerant piping
  • removal of the coil to the outside for cleaning
  • re installation
  • nitrogen purging
  • brazing
  • evacuation
  • restart.

Our fee for this job was in the $500-600 range. It is akin to surgery on an air conditioner.

But not any more. We (well mostly Jarrod) built a machine that we have used for about 10 years that allows our technicians to clean your indoor coil while it is in place in the air handler. No opening of the refrigerant system and it takes half the time. So it’s cheaper too.

Because of the high cost of the old way, many customers would just live with the dirt, reduced performance and higher utility costs. In the past 10 years we have saved our customers thousands of dollars with our gadget and given them a clean-as-new coil.

Give us call if you have been told that your coil is dirty and needs cleaning or replacement. Heat pump air handlers start at about $380 for coil and blower, slightly higher for gas furnaces and attics.

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Testing your home for leaks

A long time customer recently purchased a home. The customer replaced a defective thermostat with a newer version that displayed interior humidity. The heat pump system in their home was a better than average two speed system.

As a point of reference, this is not an old home but one built with the past 10 years or so in Timbercreek.

We received a follow-up call a few weeks later reporting that the new thermostat was registering above 70% relative humidity. We told them that we expected 50% even though it had been raining daily.

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After checking that the equipment was operating within expected limits, I recommended that the customer call a colleague who performs our duct testing in new construction.

Mark Kennedy

Mark Kennedy

Mark Kennedy with Home Energy Conservation scheduled an appointment with our customer to perform a ‘whole house blower door test’ and allowed me to tag along and watch. Before the technology was available that Mark is able to carry with him on the job, we would have had to crawl through the attic spaces looking for visible signs of damage or errors in construction, usually with inconclusive results. Now when we suspect building and/or duct leakage Mark is the first call we make.

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Preparation for Blower Door Test

Mark affixed a calibrated blower into the open front door jamb. By exhausting the interior air at very high rates he created a vacuum in the home. This pulls warm or hot air through any defects in the building envelope. This allowed the use of his next bit of magic – Infra-red imagery in real-time.

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Uninsulated areas of the ceiling where the wall joins – normal for 10 year old homes

Two hours of inspection revealed many openings that he included in his report to the homeowner. I have included of few of the images from that report:

Doggy door

Doggy Door to garage area

Recessed ceiling light fixture

Leaking recessed ceiling lighting fixture. There were dozens in this home.

Plumbing wall openings at top plate

During construction the top plate was left unsealed around plumbing stacks allowing heat and moisture into the home

Fireplace

The largest leak was from an open flue on a gas fireplace

Most of the problems found on this inspection called for repairs by trades other than HVAC. Also, some of the leaks will not be practical to correct. But the reason I am posting this is to let you know that here is a relatively inexpensive method to discover definitive answers to where the moisture is coming into your home. Or why your heating and cooling utility bills are higher than you expect.

Mark found aluminum windows that are leaking, flooring that was not caulked to the baseboards, etc.

With a report such as this any homeowner can develop a plan that allows them to know up front what the costs of correction will be with a reasonable expectation of success.

Once this plan is complete we will follow up with a second test. With that new measurement, we will calculate the size of an outside air duct to pressurize the home. This duct pulls in outside air, dehumidifies it and allows it to exit at low rates through the leaks that remain to be repaired.

The customer can monitor the hygrometer on the thermostat to evaluate the effectiveness of the corrections. I will post the results in this space when we’re finished.

Posted in Air Conditioning, Ductwork, Humidity, Mold, Odors, Technology | Tagged , , , , , | Leave a comment

Termites and your air conditioner

Pest control companies spend some of their time during inspections looking for wet areas under or around your home. These wet areas can attract termites. Drips from plumbing with just a few drops a minute are enough to cause the problem.

3termitetubes

Termite paths into your home

Air conditioners produce gallons per day and most installations dump this water right at the foundation of your home. Besides being unsightly and a possible source for mosquito breeding, chronic wet soil can draw termites to the foundation of your home. Foundation drainage

We offer the installation of a small drainage field at the exit point of the air conditioner’s condensate drainage. What is necessary is an area about 5 or 6 feet away from the outside wall of your home where we can dig and install this field.Foundation drainage-2

This drainage system may require periodic attention just like your air conditioner’s existing drain. But it will dry up the area at your foundation. Even if your home has no known problems this is a good practice to prevent future problems.

Posted in Air Conditioning, Condensate Drain, Humidity, Mold | Leave a comment

Water condensation under house

Yesterday I had a conversation with an insulation contractor regarding the installation of insulation (say that three times real fast) in a client’s attic. This prompted the post yesterday about water stains on the ceiling.

Today we were involved with a different client’s insurance adjuster regarding water damage on a floor. The flooring was buckled inside and an under house inspection showed water drops beading on the wood floor joists.

This home is probably 50 to 60 years old but we have seen new homes with similar problems. This home was constructed over a ventilated crawl space, uninsulated wood floor, finished wood interior surface.

This is the fifth home we have been involved with this summer but this time there is no ductwork under the home. If you read yesterday’s post linked to above you can see a pictorial description of the thermal properties that must be understood to address and solve this problem.

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The photo above shows several colonies of mold growing on the wood. Notice on the joist at left that the bottom has fewer colonies.

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This photo shows the underside of the plywood subfloor. The light patches are mold.

Sweating Floors

Overview of crawl space flooring system

Here is a drawing of the floor system showing one solution that I have used in the past when there is no ductwork in the space. The resistance from contractors is usually something along the lines that you can’t seal up the crawl space; that it must ‘breathe’. This is not the case. The goal is to establish a vapor barrier between:

  • the crawl space and the exterior wall/ambient air
  • the crawl space and the earth below

Caveat: This method only works with a gas permeable flooring surface. Vinyl sheet or ceramic tile is not gas permeable. A wood floor with polyurethane finish might be a problem. Older floors or the newer prefinished wood seems to work OK. But do your homework here before starting.

Also this method is inadequate for crawl spaces that contain air conditioning ductwork. We have a different solution for those spaces.

This method uses your air conditioning system to dry your floor and the floor system dries the crawl space.The reason it won’t work with the flooring materials mentioned is that vinyl sheeting prevents migration of moisture from the crawl space to the home. This blocks the path of dehumidification. It does work with a wood floor or carpet.

Section view of hanging sheet detail at exteerior wall

Section view at perimeter pier

Description of work:

Lay a sheet of 6 mil polyethylene sheeting north-south from one wall to the opposite wall between each set of the interior piers. Lay another sheet east-west , wall to wall atop the first sheet. Perimeter vents must be sealed tight, then nail a hanging sheet (two feet longer than the perimeter wall is tall) from the floor sill beam down atop the sheet you placed on the ground. Weight this sheet with bricks every few feet. Run this hanging sheet around the entire perimeter of the house.

Let this hanging sheet cover the access door so that you must push it up out of the way to enter the crawl space. Foam the ground sheet to each pier.

You will not achieve a perfect seal but the better job you do in sealing, the drier the space will be. The path for the moisture from the crawl space to the air conditioning system is restricted by the flooring. A leaky crawl space may overwhelm the ability of the system to dry the space.

The construction methods in use in many of today’s homes with crawl spaces are flawed and intended for another part of the country. I’ve seen this in new homes (recently), I’ve seen this in old homes, I’ve seen a home change occupants then develop the problem. The colder the home interior temperature, the worse the condensation problem will be. I have seen this problem for decades and, before blogs and Facebook, I’ve had to give this speech a thousand (OK maybe fifty) times complete with hand-waving and scratches on legal pads. I’m putting this together for an insurance adjuster and I’ll just email him a link. I thought since I’m writing this anyway I would share it with you. Hope it is of some help.

 

Posted in Air Conditioning, Humidity, Mold, Odors | Leave a comment

Water stains on ceiling

Every August we receive a few calls from customers complaining of water stains on their ceilings. We arrive with a short rake and sometimes a leaf blower and find that their ductwork has been covered with blown-in insulation. We remove the insulation from the ductwork and the problem goes away.

Seems like it should work. Why have those cool ducts baking in a hot 120 degree attic when a little blown-in insulation will keep them cool. Sounded good to me. Until one day while chasing the cause of a water stain in Daphne and I put my hand down into 2 feet of insulation and felt soaking wet insulation around a perfectly sealed and insulated duct. I pulled all the insulation away and the problem was solved.

Here is a pictorial drawing of the thermal properties involved in the problem. In this duct buried in insulation, it is wrapped with 1.5″ foil faced wrap and covered with 4″ of blown insulation. In a ventilated attic, humid air of 91 degree dewpoint travels through the blown insulation and condenses on the 78 degree foil facing of the duct insulation.

Sweating duct

The blown-in insulation is causing the foil faced vapor barrier of the ductwork to cool down. This doesn’t occur when the ductwork is in the open attic. The solutions to hot ducts is outside the scope of this article. But always remember to instruct anyone installing insulation to install the insulation so as not to contact the ductwork.

Posted in Air Conditioning, Ductwork, Humidity, Mold | 1 Comment

Freon prices on the rise again

We have received notice from several vendors today of a pending price increase on R22 refrigerant. If your air conditioner is more than 10 years old it is likely you have R22 refrigerant in your air conditioning system.

Swinson Air Conditioning’s last major purchase of R22 refrigerant was about 5 years ago. At that time we began a company transition away from R22 towards replacement ‘bridge’ refrigerants. We successfully completed that move so that refrigerants are not an issue our customers must consider.

We convert systems several times per day reclaiming the used refrigerant and installing our preferred replacement product. It has not been without challenges as the refrigerant properties are different. But we are able to change your existing equipment to eliminate the need for R22 refrigerant. Some of the components are off the shelf and readily available. American Standard/Trane Electronic Expansion Valves are converted by a little solid-state gizmo we designed and built ourselves.

Our converted systems can be recharged at less than half the cost of R22 saving you money. Everyone here has trained and developed our techniques to allow a seamless move away from obsolete R22 refrigerant.

Please read other postings on our blog for more information of this subject.

Posted in Air Conditioning, Freon, Humidity, Refrigerant Leak, Technology | Tagged , , | Leave a comment

Price increase on refrigerant

If your air conditioner is over 10 years old there is a good chance that it uses R-22 refrigerant. We have experienced a large price increase this spring after petitions filed with the United States Department of Commerce and the United States International Trade Commission against Chinese dumping.

Years of below market prices for R22 refrigerant have come to an end and we expect a doubling of R22 retail prices before the middle of this summer.

However…

We have a solution that is actually less expensive than last summer. We are stocking on our service vehicles a replacement refrigerant that has demonstrated the capability to be a ‘drop in’ replacement for R22. Also it is currently less than half the price of R22.

Nevertheless, the least expensive path to air conditioning operation includes the immediate repair of all refrigerant leaks no matter how small. So, we have a bridge to the future that allows you to use your current air conditioning system until replacement is required.

Posted in Air Conditioning, Freon, Refrigerant Leak, Technology | Leave a comment

Aluminum Coils and Air Filters

Some of you have had to replace your air conditioner’s or heat pump’s cooling coil in the past few years. If your new coil is constructed of aluminum there are some changes you may be interested in. The changes are for the better in the long term but there are things you should know that will be reviewed here.

When, in the interest of efficiency, home air infiltration was reduced starting in the 1970’s the air inside of homes became more contaminated because the air was not exchanged as often. Some of this was noticeable to the occupants but other events were observed by your air conditioning technician.

Technicians started to notice that copper indoor cooling coils leaked refrigerant after 5 to 8 years of use compared to 20 or more years previously. One cause among others was the increased concentration of chemical compounds of chlorine and sulphur in household air. These compounds react with the copper tubing used to manufacture cooling coils.

A ForeFront Air Handlers Coil beauty color

American Standard ForeFront Air Handler All-Aluminum Coil

Some manufacturers switched materials and now construct their coolings coils with aluminum tubing which is not affected by these chemical compounds. One benefit we in the industry have seen is a large reduction in refrigerant losses because of leaks. These aluminum coils are actually reducing by a large factor the amount of ozone depleting chemicals released into the atmosphere. A larger benefit to the homeowner is the extended life of the outdoor unit. Running an air conditioner with an insufficient refrigerant charge shortens the life of the compressor.

But there’s always a ‘but’. Copper coils were performing a function I was unaware of. Copper is toxic to mold and it was treating the drain piping, after a fashion, with copper sulfate and reducing drain problems.

American Standard® started using aluminum in about 2005 and we have noticed a slow increase in the frequency of drain problems and, to the observant technician, a change in the color of the mold clogging the drains.

IMG_4004

Light colored mold on the ground flushed from an aluminum coil

Aluminum is not toxic to mold so it provides none of the treatment that copper coils performed in the past.

 

Mold has three necessary conditions to propagation:

  1. Darkness or absence of ultra-violet light
  2. Water or damp air greater than 60% relative humidity
  3. Food

As conditions 1 & 2 exist in all air conditioning equipment, to break the chain of mold propagation we can eliminate # 3 – depriving it of a source of food.

Household dust is comprised of hair, fibers, skin cells and other small particles. Visible particles such as hair and fibers are easily caught with most air filters. But smaller particles require improved filters to remove them from the air stream and the cooling coil.

Fiberglass Air Filter

Fiberglass air filter

Don’t consider using this filter on an air conditioner. Small particles fly through it easily. This filter is ineffective in the control of mold.

panel-air-filter-392070

Pleated media filter

Pleated media filters are better as they catch the smaller particles like skin cells; but they restrict the flow of air and reduce the efficiency of the air conditioner. Also in variable speed indoor units, that restriction causes the ‘smart’ blowers to speed up to overcome the restriction and increase electricity consumption.

Return Grille Filter

In-wall 5″ thick media filter

air-cleaner-filters

Cartridge media filter

There is now available an easy solution that requires little to no installation costs. Five inch thick pleated media filters that usually fit in your wall return air grille. These filters can be ordered online directly from the vendor. The source we have been using can be found here. Make certain you measure your existing wall grille before ordering. This is such a good option that we recommend replacing your wall grille to match the available filters if you find that necessary. We can replace the wall grille for you.

If your return duct system is leakproof and you are diligent with air filter replacement you can eliminate drain problems with your air conditioner.

Posted in Air Conditioning, Allergies, Condensate Drain, Dirty Sock Syndrome, Mold, Odors, Technology | Leave a comment

Fireplaces and your central heating system

Christmas_Fireplace

Fireplaces offer a cozy view and a warm, radiant heat to enjoy in your home. But, if your primary source of heat is from a central heating system, a fireplace can waste the fuel it consumes along with the fuel used by the central system. It will also make the farthest places in your home colder. 

Fireplaces can be fueled by wood or natural gas. One pound of fuel requires 15 pounds of air for combustion. Unless your fireplace has an outside air source, this air comes from your already heated home air. In addition to combustion air, the heated flue pulls in another 15-20 pounds of air from the house to the outside.

00-tiling-fireplace-1208-xOpen fireplaces are a primitive method of home heating.

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Glass Fronts can reduce the amount of air drawn from the home.

LOPI LEYDEN WOOD STOVE

Wood heaters

and 

regency-wood-insertFireplace Inserts

that contain a heat exchanger capture the heat that otherwise would go up the chimney with the smoke. They can provide heat to the home along with a central heating system.

If your primary heating system is a central gas, electric or heat pump system, the system should be turned off during operation of an open or glass-fronted fireplace. Wood Heaters and Fireplace inserts, on the other hand, can be operated together with a central system. In this part of the country they can produce much more heat than necessary to heat a home and are operated in a throttled condition. A variable speed fan on your central system can be used to distribute this heat to the rest of the home without causing a drafty feeling.

Prefabricated fireplaces now outnumber masonry fireplaces. They are much less expensive to build. I see very few of these with a heat exchanger like you would find on a fireplace insert, but that type does exist. The majority of these use gas logs with a triple-wall flue to the outside and have the efficiency drawbacks of masonry fireplaces as described above. There is a way to use these for home heating in an efficient manner: Vent-Free Gas Logs.

VentFree_GasLogs_61_P

Vent-Free Gas Logs come with an Oxygen Depletion Detection System and do not produce dangerous carbon monoxide. They can be operated with a closed flue or without a flue. This makes them nearly 100% efficient in operation. They do present drawbacks compared to a central system; all products of combustion are dumped into the living space.

The products of combustion are:

  • trace amounts of hydrogen sulfide
  • large amounts of water vapor
  • Carbon Dioxide

Hydrogen sulfide is not noticeable to humans in trace quantities but it is a corrosive gas. Large levels of water vapor raise the relative humidity in the home and can cause sweating of glass and window sashes. Carbon Dioxide is non-toxic to humans but elevated concentrations can make you drowsy. This is controlled for with the Oxygen Depletion Sensor that is part of a vent-free gas logs device.

I’ll include a note here about Carbon Monoxide. Carbon Monoxide is toxic and accumulates in the blood. It is created through the incomplete combustion of hydrocarbon fuels. High accumulation in the blood can be fatal. The symptoms are similar to influenza. If you have propane or natural gas supplied to your home you should own one or more carbon monoxide detectors. They are incredibly cheap and very reliable.

Gas logs are a much cheaper way to achieve high efficiency gas heating. A comparable 96% AFUE efficient Gas Furnace can cost as much as $5,000 or more. But of course there is a trade off – Gas logs degrade the quality of air inside the home.

I remember going to an elderly aunt’s home in Mobile in the 1960s who heated her home with free-standing radiant gas heaters. The indoor environment was oppressive because of the elevated humidity and odor of combustion products. I didn’t, of course, know these causes at the time but the indoor air was unpleasant nonetheless.

New furnaces draw combustion air from outside the home, recover almost all heat from the fuel and then dump the products of combustion outside. All this without adding or removing anything from the air inside the home. Gas logs are used primarily to heat the room with the logs and to also enhance the ambiance. As nice and quiet as our furnaces are, they’re not much to curl up in front of.

Posted in Heating, Humidity | Tagged , , , , , | 1 Comment

IAQ – Allergies and Asthma – Odors in your home

A visitor to your home will sense them more quickly than you. Prolonged exposure makes them invisible to you. You will often notice them when you first arrive home. Odors are part your body’s self-defense warning system.

Dogs, cats, hamsters, carpet, cooking, people all give off cells, hair, fur, gasses, VOC’s that are detectable to the human nose. To some people it’s just a smell. To some it can trigger an allergic, histamine reaction. I’m not an expert in allergies but my work involves dealing with the conditions related to humidity and air filtration. Controlling relative humidity in South Alabama is a larger part of maintaining comfort than in most other non-coastal locales. Mold grows in humid conditions so that makes air conditioning technicians a resource for controlling airborne mold inside the home. We apply and repair the equipment that controls humidity, and filters particulates from the air.

Newer houses are constructed to leak less air than older houses. This trend started earlier in the North as heating homes uses quite a bit of fuel. Energy efficiency in air conditioned homes moved this practice to the southern United States in the 1970’s. I mention this to point out that you live in a different structure from your parents. The home you grew up in during the 1950’s, 60’s, 70’s and 80’s exchanged air more freely with the outside which reduced the concentration of various pathogens and chemicals. Tightening up homes creates a different indoor environment but ventilation practices have not kept pace with these changes.

Ventilation – Kitchen range hoods carry steam and aerosol oils from cooking directly to the outside. The best way to keep cooling odors reduced is the kitchen range hood. Open the cabinet above your range. If there is no duct visible you probably don’t have a vented range.

Use bath exhaust fans after showering until the mirrors clear and then 15 minutes longer. Consider removing the inexpensive fan that came with your home and replacing it with a larger model. Quiet models with heaters for winter use save energy by heating the bath while you are damp from bathing. Removing excess humidity reduces the moisture necessary for mold spore propagation.

Air Filters – There are several options available here. Even the least expensive is effective if they are changed regularly. panel-air-filter-392070How often depends on your home: More often in summer, less often in winter. Looking at them is a good indicator of the correct interval.

Extended surface filters are a good option but are not always commonly available. air-cleaner-filtersThe advantage is that they offer less resistance to airflow while still filtering a very small particle. People that use them properly gain the advantage of clean equipment and extended life. The dirt that collects on the cooling coil accelerates corrosion that leads to refrigerant leaks and the moldy odor noticed when the air conditioner comes on. Customers sensitive to that odor usually call us asking to have the ductwork cleaned. Here is a photo from a few weeks ago.

Dirty indoor Cooling Coil

Dirty indoor Cooling Coil


Click on the image and you can see at the bottom where I cleaned a small section with a wire brush. The rest of that is mold living on the coil. It is more common to see this than not. Once mold gets started, it maintains itself very easily and is difficult for you to remove.

Carpet – Carpet can be cleaned. The pad under a carpet cannot be cleaned. Dirt from outside sifts through the carpet and pad and forms a silt-like layer on the underlaying floor. If you watch carpet being replaced, look at the fine powder on the floor under the pad. 3 month air filters last 3 months in a carpeted home, 6 weeks or less with wood or tile (2 to 4 weeks with pets). Air filters last longer in a carpeted house because carpet catches a large amount of dirt. Carpet in a home collects years worth of debris from shoes, skin cells from humans, spills, dust mites.

The dirt under the pad can have dust mites which can trigger allergies. It also has bacteria in abundance; not ‘can have’ but ‘has’. Interior relative humidity above 65% provides an ideal environment for mold. Mold propagates well in dark, damp places and bacteria is a food-source for mold.

A normally functioning central air conditioner will maintain right about 55% relative humidity (rh) many months of the year .  In the spring and fall during mild weather you will see 60 to 80% rh for extended periods.

If you are having allergic reactions and you have carpet, consider hard-surface flooring as an alternative.

Dirty sock syndrome – This condition mostly affects heat pump indoor units. The aluminum fin of the indoor coil becomes etched chemically in a short time of operation forming microscopic fissures in the surface of the fin. A cooling coil in a typical home has up to 300 square feet of aluminum fin surface. Mold growing on these 300 square feet gives off a moldy, dirty sock odor at the first start-up in the winter. The wet mold in the fissure is heated by the heat pump operation and gives off a very strong repugnant odor for a day or so until the heat kills it. In the fall we routinely switch between cool and heat which generates a new crop of mold and odor.

Containment – Laundry hampers, compost pails and closed garbage cans can prevent odors from building up in your home. Damp clothes, food scraps and household garbage emit products of decomposition that linger and accumulate in textiles in your home. Containing them reduces the odors.

Pets – Control of pet odors varies with the pet. In my life I have had hamsters, rats, birds, cats, dogs, iguanas and probably some that I forget. I won’t go into the varied types of odors and requirements of keeping down pet odors. Litter boxes, cages, and the pets themselves all require different measures. Assuming that each pet is cared for and their quarters are clean, there are still odors that can be readily detected by visitors. For this there is a magic bullet(s). Oxidizers. That annoying guy on the Oxiclean commercials is selling a product that uses this principle in cleaning fabrics. It can also be used to clean air.

There are devices available that generate oxidizers, mainly ozone and hydrogen peroxide. These are molecules that are dispersed into the living space from devices inside the return or supply duct. These devices consume less than 25 watts of electricity to power ultra-violet lamps.

Ozone and hydrogen peroxide react with mold and viruses in the ductwork and in the household environment killing them and/or stopping their propagation. Ozone (O³) is generated with a less expensive device than hydrogen peroxide (H²O²). Peroxides have a less noticeable odor than ozone. Also, there are limits to the amount of ozone you want in your home as it can irritate lung tissue. Peroxide generators are surprising in their effectiveness in eliminating odors inside the home. Installed cost of a peroxide generator is about $1,000.00 and they require an element replacement every 3 years at a cost of about $350.00. This gives an annualized cost of operation over a 15 year period of $165 per year or 44¢ per day. It is a luxury but it is a nice luxury. It can really make your home smell fresh with no masking odor. Also there is a reduction in allergens which can reduce histamine reactions.

Other points in your home to review are mainly structural in nature. Some structural issues are air conditioning related because of the temperature of the building materials and the humidity of the outside air. I will go other some of these items in future articles.

http://www.swinsonac.com

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IAQ – Allergies and asthma – Ductwork

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IAQ – Allergies and asthma – Indoor AC Equipment

Indoor Air Quality

In the previous article on Indoor Air Quality, the section of your air conditioning system from the wall filter to the indoor equipment was covered. This installment covers the indoor machinery. Two types of equipment are used depending on the fuel used for heating. If you have a gas furnace your indoor cooling coil is less accessible than if you have a heat pump.

Dirty Indoor Cooling Coil

Dirty indoor Cooling Coil

Above is a view of the inlet to a cooling coil (click for enlarged view). All air that moves through the cooling system passes thru this coil which is wet and functions as a very efficient air filter. The coil remains wet during cooling operations and collects nearly all dirt and debris that is not filtered upstream. This coil is very difficult and expensive to clean and that is one reason why timely filter replacement is so important. Look at the lower center section to see an area that we cleaned with a wire brush. This coil is over 2 inches thick; a wire brush cleans the first .125 inch so it only clears debris from the surface.

Dirty Blower Wheel

Dirty Blower Wheel

This isn’t a great photo but it shows typical growth of mold on a blower wheel. The blower is after (downstream of) the cooling coil. You would think that air would be dry after leaving the coil but it leaves the cooling coil at 100% relative humidity. The air going through the blower deposits dirt on the blades reducing their effectiveness. Also, the blower section is dark and wet so the bacteria in the dirt furnish everything necessary for a mold colony (shown as round globs in the photo).

There is very little a homeowner can do to clean this equipment. Before the introduction of the American Standard ForeFront® Air Handler, air handlers weren’t designed to be cleaned, even by professionals; cleaning was a difficult, improvised process.  Proper filter replacement schedules mean that the interval between air handler cleanings can be 10 years or more.

The next installment will deal with mold in ductwork and duct cleaning, one of the most frequently asked questions we receive.

http://www.swinsonac.com

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IAQ – Allergies and asthma – Return Air Duct

SneezeIndoor Air Quality

Allergies and asthma are triggered by the body’s reaction to substances in the environment. Sometimes the cause is:

  • known from experience
  • told to you by your physician
  • unknown

I am starting a series of short articles on these problems and how they relate to air conditioning. This guide will allow you to investigate it yourself or to look over the shoulder of a technician. There are many deceptive practices in the field of mold remediation; some of it is just overkill on a problem; some is dishonest; some is inattention to the problem. As in all issues of your health, it is up to you to keep plugging away and asking questions until you find your answer.Heater Closet - 1

Our interest here is to ascertain how well the system is sealed from the outside air and that air’s entrained moisture and contaminants. The first place to look is the largest air grille in the system, the return air grille. Starting at the return grille to the supply grille where the conditioned air enters the home, all surfaces inside the air conditioning system are shielded from view and cannot be cleaned by the homeowner. The purpose of these articles is to explain what goes on in these spaces.

At this location you should see an air filter. Many homes have the filter in the furnace or air handler and not here at the return air grille. Having a filter at locations other than the return air grille is universally sub-standard. Not having a filter at the starting point of the system causes heavy accumulation of household dust under the furnace and in the return air plenum or return air duct.

Open this grille and use a flashlight to look around the space.

1. If the furnace is in the closet above you –
The only holes should be the ones for the filter and at the bottom of the furnace; the rest of the space should be ‘bubble-tight’. This is very important. When the filter is in place, the plenum is at a negative pressure and will pull air in through every crevice. As the filter loads with dirt, this negative pressure increases. This intruding air is unfiltered, humid and from the attic.

If there are holes, the repair for this does not require high skills; it is pretty tough getting in and out of the hole amongst the piping nonetheless.

The preferred material is 1/2″ thick sheetrock but that is during construction. After the fact, we use 1/2″ styrofoam exterior building sheathing and expanding foam. We are attempting to build a smooth, sealed, cleanable enclosure between the return air grille and the furnace.

2. If the furnace is under the house or in the attic –
Most homeowners are out of their depth at this point. This space behind the return grille is an extended duct to the furnace. Reliable repairs to duct material require developed skills and only the handiest of homeowners should make these repairs. As with the closet mounted furnace, this section is at a negative pressure and pulls in outside air if defective. Here is a good tip for anyone with a furnace in the attic. If you are spry enough to walk the ceiling joists of an attic or it is decked, look at the point where the return duct rises through the ceiling to the attic. There will be insulation covering this location. If the insulation is dirty in a ring 4-6 inches away from the duct, you have found an important duct leak. The negative pressure from the duct is pulling air through the insulation. The insulation filters dirt from the air and becomes darkened with age.

Modern air conditioning works best when it doesn’t have to process new air. It recycles the same air through the system removing moisture and heat and contaminants. In a normal house, clothes dryers, range hoods, bath fans and door traffic supply plenty of fresh air.

If you are going to win the battle with mold you have to deny it the things it needs to live:

  1. moisture
  2. darkness
  3. food

If you live near me, your summer consists of 8 months of 90% or higher relative humidity. Mold cannot grow in an environment of 55% relative humidity or less. When we replace indoor air conditioning equipment, we always improve the seal; very often we find huge holes that have been pulling attic air into the house, sometimes for decades.

If you will follow the things I post on here in the coming weeks you can educate yourself about mold allergies related to duct systems. This treatment of the return duct is just the start of the process but I will take others in turn. Some houses are easier to correct than others but the causes of mold allergies are known causes. There is no reason for you to suffer in your home from allergies caused by your home.

http://www.swinsonac.com

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Good news about freon leaks

In preparing our annual refrigerant purchase in light of the upcoming refrigerant phase-out I made a surprising discovery.

Refrigerant usage analysis

Click on the link above and you will see the result of American Standard’s all-aluminum coils sold by Swinson Air Conditioning.

Our fiscal year starts on Oct 1 so the year 1998 is truncated. What the chart indicates is the more than halving of R22 refrigerant sales in a record overall year for Swinson Air Conditioning. American Standard changed production of indoor cooling coils for gas furnaces in 2004 and heat pump air handlers in 2010 to all-aluminum manufacturing.

We started to emphatically recommend to our customers that they not repair their copper coil indoor equipment but to let us replace it with all-aluminum machinery. It has taken some time to get traction but last year’s sales of R22 is down more than 50% by weight over the previous year.

We place a special emphasis on locating and repairing refrigerant leaks because we see the year to year expense that the repairs can stop. This drop in sales represents large savings for our customers as well as a reduction in the release of refrigerant gas to the atmosphere. And the savings extend into the future at no additional cost to our customers.

This illustrates our commitment to do our part in giving you a comfortable, healthy home at the lowest expense.

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What happens when R22 refrigerant (Freon) is no longer available?

Most air conditioners that are older than 10 years of age use R22 refrigerant. R22 was introduced in the 1950’s and became the predominant refrigerant used in residential air conditioners and heat pumps.

In 1989, the United States was a signatory to the Montreal Protocol that requires a 90% phase-out of consumption by 1-Jan-2015. That is just over one year away. Most new equipment manufactured in the past decade uses R410a refrigerant which is much less expensive and more widely available than R22. So what are your options?

  1. You can install a new system that uses R410a
  2. Install a substitute refrigerant
  3. Repair your system so that is doesn’t leak refrigerant

I will go over some effects of each option listed above.

Option (1) has the highest initial cost. If you have an old inefficient system with leaks located in the outdoor unit and/or your electrical utility bills are higher than they should be, this may be your best long term solution. Sometimes you don’t want to spend this much right now. So lets look at Option (2).

Option (2) is an option available for a medium term of 1 to 3 years. We have refrigerants that are not R22 or R410a but are compatible with your extant outdoor unit at a lower cost and higher availability that R22. Substitute refrigerants do have a few drawbacks. These refrigerants decrease the capacity and efficiency of your existing system by 5% to 7%. Also, they require the replacement of the fixed orifice in your indoor unit with a larger bore device. This is done by trial and error at the time of refrigerant conversion. You may not know what I talking about here by your air conditioning technician does. If your existing indoor unit uses an expansion valve instead of a fixed orifice, the valve must be replaced with a valve having a 20% larger capacity than the current valve. So the initial conversion is more expensive than subsequent recharges. Option (2) has seen very limited use by Swinson Air Conditioning; it is not the best long term solution for most of our customers.

Option (3), repairing the leaks, comprises a major part of the time spent by us in the field. We have very few regular maintenance customers that have refrigerant added every year. Adding refrigerant instead of repairing the leaks is a terrible plan for low cost air conditioner operation. When we add refrigerant to your system, the next thing we do is ask if you would like us to locate the leak. Most people do want the leak located and most of the leaks are located at the indoor

Corrosion on copper coil

Corrosion on copper coil

copper coil, some leaks are on the access ports where we connect the gauges, some on rusted out driers or accumulators in the outdoor equipment. Where ever the leak is located, if it is a repairable leak, you want that leak repaired regardless of the refrigerant availability situation. Operating a leaking system is false economy. See this previous post for more information on Option (3).

So that sums up the refrigerant phase-out situation. Each of these options can give you a future of reliable air conditioning operation with lowest possible cost.

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Do I have to replace my entire air conditioning system?

Several times per day, our technicians add refrigerant to air conditioning systems. Each of these systems is leaking refrigerant. Air Conditioners do not consume refrigerant; they only leak it. A well maintained and repaired air conditioner may run 20 years on the original refrigerant charge.

Corrosion on copper coil

Corrosion on copper coil

The biggest source of leaks is the indoor coil. Most every brand is manufactured with copper tubing. American Standard is different. All split-system indoor and outdoor coils

American Standard ForeFront Air Handler All-Aluminum Coil

American Standard ForeFront Air Handler All-Aluminum Coil

in our indoor and outdoor units are made with aluminum tubing.

When you replace the indoor coil with a direct replacement for what is currently installed, you are limiting your future options on the outdoor unit selection. You can replace just the indoor coil but I only advise that on houses that you don’t plan to own for very long. Even if you do plan to sell soon, older equipment results in a lower appraisal during home inspections; some of the savings of a replacement coil are offset during the sale.

I always advise the installation of a coil that is compatible with a high-efficiency outdoor unit. Our procedure here is to:

  • Install an indoor coil (for gas furnaces) or air handler (for heat pump systems) that is compatible with a 15 SEER or higher outdoor unit using R410a refrigerant
  • Convert it to R22 refrigerant if that is what you are currently using
  • Leave the parts from conversion with the homeowner for future use with a future outdoor unit.

The wisdom of this approach is in the reduction of wasted material and labor. Also, the repair expense is spread over two events; now to correct the leak and later when the outdoor unit does fail.

Another advantage is an immediate increase in efficiency. While the outdoor unit consumes most of the electricity, the indoor coil plays a large role in that consumption as well. The indoor coil meters the flow of refrigerant through the system. Older coils often use a fixed orifice to meter the quantity of refrigerant through the coil. In older less efficient systems this was acceptable. Newer systems operate at a lower compression ratio and are more sensitive to lower ambient conditions. All quality systems now use either TXV’s (thermostatic expansion valves) or EEV’s (electronic expansion valves). These valves modulate in reaction to varying indoor and outdoor conditions. The valves allow the use of more of the indoor coil in cooler weather and remove much more water from the air.

Copper coils weren’t always leak problems. There are several reasons that merged in the past three decades to make them a huge expense for a homeowner. All-aluminum coils solve many problems and save many tens of millions of dollars in expense over their lives nationwide.

So to return to the question posed in the headline of this article, do you have to replace the entire system. You can confidently replace just the indoor unit by itself. You cannot replace the outdoor unit without a matching indoor unit. That is the reason for installing an improved indoor coil or air handler now. That prepares your system for future upgrades without the wasteful discarding of good equipment at that time.

Posted in Air Conditioning, Freon, Refrigerant Leak | 2 Comments

Why compressors fail

A compressor failure is one of the more expensive of common failures of air conditioning systems. I’ll describe in this article the causes and prevention of failures. First I’ll explain what job the compressor has in cooling your home.

Cut-away view of modern compressor

Cut-away view of modern compressor

The compressor is a device weighing about 100 to 150 lbs and is inside the outside air conditioner in the yard. It takes cool gas from the indoor coil and compresses it to a higher pressure in the outdoor coil. At this higher pressure the gas’ temperature is above that of the surrounding space allowing it to reject its heat.  Inside of its welded steel shell is an electric motor close-coupled to a gas compressor. These components spend their working life in an environment of refrigerant gas, without oxygen and moisture, bathed in oil. The motor draws its power from terminals bonded to the side of the shell. It is the job of the Air Conditioner installer to provide this oxygen-free, moisture-free condition during installation.

If your tooth hurts, avoiding an appointment with the dentist is not a good plan. Likewise, if your air conditioner seems to perform less well than before, have it inspected.

High Operating Temperature – Probably the single biggest cause of failure is long term operation with a low refrigerant charge. The compressor is the last item in a long circuit (up to 100 feet) that is cooled by refrigerant gas. When your system’s refrigerant charge has partially leaked away the compressor’s operating temperature rises while the interior of the home continues to be cooled.. If the leak is slow, it may operate for years at this higher temperature.

Capacitor Failure – The compressor in residential equipment is dependent for operation on devices called capacitors. Capacitors can change their electrical value over time and this change is detected by a good program of maintenance.

Dirty Coils – Inside the home and outside are heat exchanger coils. Depending on the season, one is hot and one is cold. Fouling of these coils increases the compression ratio the compressor operates under. This causes it to use more power, operate more hours, and operate outside of its designed conditions.

This is not an exhaustive list but covers quite a few failures. If you are not mechanically inclined to address these yourself, annual maintenance by a professional is a proper step toward lower operating costs and longer life for your equipment.

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Capacitor failures

American made capacitor

American made capacitor

http://www.airstarsolutions.com/Documents/CheapCapacitors.pdf

If you are experiencing repeated failures of capacitors in your air conditioning system the problem may lie in China. Fifteen or twenty years ago the production of capacitors was moved out of the United States to countries such as Mexico, Brazil and Indonesia. About five to ten years ago we began to notice ‘Made in China’ on the capacitors.

Capacitors are not very expensive; the labor to replace them and the vehicle and fuel to get the labor to the machine are the major cost.

When I started in this business forty years ago, capacitor failure was not that common. Three or four years ago the warranty labor required to support the sale of capacitors became so high that we were charging a very high price to install them. This caused me to start a search for an alternative and the result was serendipitous. I found two manufacturers in the United States: Genteq and AMRAD.

We made the decision to purchase these at an average 400% higher price than the Chinese capacitors they replaced. The failure rate is below 3%; it was 130% at 18 months with the old ones.

Best part of the story: We have lowered the price of capacitor replacement even though we pay more. Why? The large reduction in warranty labor. We win and the customer wins.

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Duct Integrity Testing to combat allergies and mold

There is one complaint from a homeowner that is very challenging to a technician: “It cools but seems to run a lot. ” After going through all the standard problems that affect an air conditioning system we are left with a question of capacity; is the system large enough for the home. Sometime during the construction of the home, the air conditioning contractor’s job was to evaluate the sources of heat gain/loss in the yet-to-be-built home and design a cooling and heating system. Some years hence an occupant of the home calls with the above complaint and the technician is left to find out: Is the system broken or was it ever large enough?

The decision tree branches a bit at this point but one of the newer tools available to us is duct pressure testing.

Duct Integrity Testing System

Duct Integrity Testing System

These tools allow us to quickly evaluate the integrity of your ductwork without having to spend the time with a visual inspection. In about 30 minutes we can set up this system and identify how much air is escaping to the outside or, better yet, eliminate ductwork as the source of the problem. Every year during equipment replacement we find holes on the order of .5 to 1 square foot. Often these holes were extant at original installation and presented only as high power bills. Before these electronic diagnostic tools were available, the several man-hours of labor required to inspection ductwork integrity discouraged homeowners from this test. Now for less than $100 on most homes we can answer the question; for less than $400 most homes that do have failed duct systems can have it corrected. Perhaps as important, you can know that your expensive conditioned air is staying in your home.

You should consider duct integrity testing as an essential test for home rehabilitation.

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Water dripping from ductwork in attic

Do you see a series of water stains on your ceilings in different parts of your home? Every few summers a set of conditions occurs that uncovers a fault in many homes. Blown-in insulation often covers the ductwork in the attic. This causes the outer foil surface of the ductwork to drop in temperature below the dewpoint of the air in the attic.

water shield under duct work

water shield under duct work

Removal of the blown-in insulation from contact with the ductwork and the addition of a shield to catch any water from dripping on the ceiling are the recommend repair.

When adding attic insulation, instruct the installers to avoid installing the insulation in contact with the ductwork.

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Blocked Air Conditioner Drain – II

A poorly performing condensate drain is top of the list on damage caused to a home by a poorly maintained air conditioner.

An air conditioner in the cooling mode produces up to 20 gallons of water per day. That is sufficient water to ruin a nice carpet, hardwood floor, sheetrock ceiling and it can go undetected for weeks or months.

Some causes are covered here. We have a few ways of preventing and detecting the problem and automatically shutting down the system before the damage is caused.

The primary method is an auxiliary drain pan.

American Standard ForeFront Air Handler installed over sheetmetal auxiliary drain pan

American Standard ForeFront Air Handler installed over sheetmetal auxiliary drain pan

This is a sheetmetal pan under an attic mounted air conditioner. In heater closets, we can install a

Polymer liner under upflow furnace or air handler.

Polymer liner under upflow furnace or air handler.

polymer liner under the furnace or air handler. These catch water overflow and direct it to the outside. They should be periodically checked. I have seen these function for years under a failed main drain pan unobserved until they also block and fail for the same reason.

The next method of detection and prevention is an inline condensate float switch.

In-line float switch installed on upflow air handler

In-line float switch installed on upflow air handler

There are several models available. The type shown (click on photo for enlarged view of tee-shaped device in white piping with wiring) in the photo is constructed with an enclosed magnetic reed switch. When the piping becomes blocked, the water level rises in the pipe tripping the magnetic switch. This switch breaks the controls to the outdoor unit and shuts the system down until the drain can be corrected.

There are several locations in the condensate drainage system where a blockage can occur. Also, no device is completely reliable due to defects in the device or maintenance conditions that go unobserved.

For folks that like the ‘belts and suspenders’ method, we can install a wet switch. This is an electronic device that sits in the pan or on the floor under the condensate pan. Three drops of water will trigger the circuits and shut down the system.

The cost of damage caused by 20 gallons of water per day can get into the thousands of dollars in a short period.

IF the air filters are replaced on schedule; IF the condensate drain is treated on each filter change; IF the drain slopes away in proper fashion and does not trap water on the way; IF the condensate pan materials don’t crack or rust over time; IF none of these events happen the drain will function for years with no problem, many do.

Regular maintenance is the best method of prevention. Additional control devices are always available but wisdom of installing them is often apparent after the damage. Every system we install over structure that can be damaged by water gets a float switch. These devices can be retrofitted to almost any existing system.

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Summertime Humidity Control in your home on the Gulf Coast

We’re getting spoiled. I can recall going into a cool home, seeing a window air conditioner and feeling how nice it was inside. No numbers on the knob; just ‘warmer – cooler’ and that was fine. As equipment became more sophisticated, we fiddled with whether 74 or 76 was just right.

010

Now we can go another step for more comfort with humidity control.

011

This is a practical system to install in your home for several reasons:

  • Thermostats like the one pictured above are actually small wall-mounted computers. They measure the temperature like the old ones and also measure the humidity of the air. They also make control decisions on how to achieve the temperature and humidity set-points you select.
  • Variable Speed Air Handlers use small programmed modules bolted on to the end of a motor to adjust the speed of the fan. 014Faster fans move more air and drop the temperature of the air faster. Slower fans move less air and get it much colder. Getting air colder condenses more water vapor from the air making the air in your home drier.
  • Two-Speed Outdoor Units have the ability to change how much cooling or heating they deliver. Having an air conditioner that is too large is a common cause of a humid house. You experience this already in your home now. Every Spring and Fall your air conditioner is too large. Have you noticed that during those seasons you have to turn the thermostat down by 4 or 5 degrees to feel comfortable. It’s not your imagination. An air conditioner that is large enough for your home when it is 98 degrees and 90% relative humidity outside is much too large for your home when it is 80 degrees and night time; it won’t run long enough to remove moisture. Two-Speed Air Conditioners solve this problem. Those two thermostat pictures above were taken on a rainy day with an ambient temperature of 75 degrees. Inside the relative humidity is 50%. A single speed air conditioner will not achieve these results.

Why do you want one of these systems in your home? Comfort is one good reason. Drier air in the summer, no cold air blowing out of the vents during start-up in the winter.  Another is your health. Maintaining the humidity below 55% will not allow mold growth in your home. That is something you learn over time when you own a system like this. But the first thing you notice is how quiet it is. A Two-Speed unit will spend almost all of its running hours on the low speed mode. At that speed it is nearly inaudible when running, inside and outside. Since it runs longer at lower speed, the temperature through the house is more even; the equipment is not turning on and off as often. Economy is another issue. These units are usually rated from 16 to 22 SEER. The will reduce the amount of electricity used.

Even if you select a single speed outdoor unit, a variable speed indoor unit has a built-in program that slowly ramps up the speed achieving a reduction in the humidity inside the home. For installations in a primary residence, this is the minimum level of quality that I recommend to my customers. Even if you select the least expensive outdoor unit, a variable speed air handler or furnace provides two decades of comfort at a very low daily cost. It is a luxury available to the common man that is worth the price.

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Blocked air conditioner drain

Something we see often in new and older subdivisions are below-grade air conditioner drains.

Below grade drain

Below grade drain

Many homes are constructed with the air conditioning condensate drain exiting the home underground. Others start off above ground but, with the accumulation of topsoil through natural processes, become buried over time.

A normal air conditioner can produce 15-20 gallons of water per day. If the path to the outside is blocked it ends up on the floor (for closet mounted units) or the ceiling (for attic mounted units).

What we find in homes with this problem is a pipe that leaves the air handler inside, travels under the foundation for 20 feet or so, then either runs into the dirt or uphill above grade, forming a large ‘U’ holding 3 or 4 gallons of water. This trapped water grows mold and eventually forms a blockage. It can be surprisingly stubborn to clear.

What we offer to correct this is to install a drain field that allows the water to be reliably dispersed.

Image

click on photo for enlarged view

A plastic pail is placed in a hole below grade, the condensate line is installed in the pail with a Tee running vertically. The pail is filled with river rocks, covered with landscaping cloth and covered over with mulch and/or grass. If the ground has a high percentage of clay it may be necessary to repeat this with a second or third pail. Trial and error is a better method for an individual home rather than an expensive percolation test.

One function of the 3/4 plastic pipe extending above grade is as an indicator of a blocked or poorly performing field. Another function is to allow a temporary path of exit for the condensate water until repairs can be made. If water is flowing out the top of the pipe, there is a problem with the field. The landscaping cloth is in place to prevent silting of the rocks and filling of the spaces between the pebbles. Algae or mold can also block this space; properly maintaining the drain as noted in a previous posting on filters will prevent this.

This method of drain field

Completed below grade drain before mulching

Completed below grade drain before mulching

can reliably operate for several years. When a blockage does occur, pull back the landscaping cloth, take a shop-vac to suck out the rocks, wash the debris from the rocks and re-install. Maintenance afterwards only takes a few minutes.

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Lightning Damage

My current home suffered 4 lightning hits in 3 years, the last one taking out the TV, phone(s), computer and Heat Pump. Before the last one, anytime two clouds approached each other, I would shut off the breakers to everything and wait for it to pass. The final hit came about 4 in the morning to a pecan tree outside. I woke up running down the hall smelling a burned circuit board somewhere.

That was about 3 years ago and I’m just now starting to relax. I knew at the time that not everyone else suffered the damage I did. I started in earnest to investigate what could be done without spending a fortune. 

The first step I took was to remove four pecan trees near the house.

Step two was to check out the wiring in my home. It was built in 1964 and I hadn’t looked very closely at the grounding. I found that none of the wiring had a third ground wire. A previous owner had replaced all of the receptacles with grounded devices on un-grounded wiring. I replaced the wiring to any receptacle that supplied power to anything but a light. 

Step three was to drive new grounding rods at the power meter, telephone interface, satellite dish, outside building panel.

Step four was to purchase a UPC with surge protection, run a ground cable from it to a ground rod, run circuits to the television, computer, modem, and security system.

Step five was to install dedicated surge protectors and the outdoor Heat Pump, indoor Air Handler, Main Power Panel, Outer Building Power panel.

Lightning can enter your home directly through an onsite strike, through a strike on or near power lines or phone lines. I know from experience that some geographic areas receive a greater number of strikes. Spanish Fort Bluff is one of them because the storms from the northwest discharge, after crossing the delta, on the first high point of terrain. 

We can install these devices for you on your Air Conditioning equipment. We drive dedicated ground rods for the purpose. Newer Air Conditioners, Heat Pumps and Gas Furnaces are operated by micro-processor boards just as vulnerable as your computer. If you are paying for damage caused by these storms you may benefit from their installation.

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Heater Closet

Heater Closet –

Often when we replace the indoor equipment of a heat pump or air conditioner we find that we could have improved the performance of the system merely by removing and re-installing it. What I mean by this is, there were defects in the original installation that we corrected during the new installation. These mainly involve correcting the sealed area under the equipment.

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The Closet –

If your duct work is in an attic, the closet is the device that separates the air inside the home from the air outside. The problem is that it is usually built by workmen that do not understand it’s functions. Further, many air conditioning installers do not understand the importance of the seal between the attic space and the space under the equipment.

The only air that enters the furnace or air handler (referred after this simply as furnace) should pass through the air filter. The preferred location of the air filter is in the wall. Many are installed in a compartment built into the furnace. This is less desirable because of the dirt that accumulates in the hard to clean area under the furnace.

The other paths that are created by a defective heater closet are:

  • Holes in the platform for piping and wiring
  • Holes in the walls under the platform
  • Gaps under the furnace caused by deformation of the platform due to furnace weight

This may seem a boring subject. It is until you consider that the air coming into the house from these defects is from the attic. This air can reach 130-140 degrees in the summer and is laden with water vapor.

The quickest tests we use can be performed by the homeowner. All you need is a thermometer and a hot or cold day.

  1. Measure the air in the room by the return air inlet grille. This is the wall opening with air moving into the wall. Then place the thermometer in the space behind the return air inlet grille. If the readings are not identical, you are pulling air from the attic.
  2. Open the door to the heater closet. Put your hand in the space a feel the temperature. Close the door and count to 20. Open it again and put your hand in the space. If it got hotter, you are pulling air from the attic.

Leaving a window open in the summer would only allow 95 degree air to enter fairly slowly. Having a leaking heater closet pulls 130 degree air from the attic.

We routinely find situations where this has occurred for decades without the owners awareness.

If your furnace is located in an attic or under the house, these considerations still apply but the the problems here are caused when the duct from the furnace to the filter grille is formed by the structure of the house. Again, the workmen that build the framing and sheetrock that comprise this duct may not appreciate how tightly it must be sealed.

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Air Conditioner Refrigerant Leak

Refrigerant leaks can occur at the indoor equipment, outdoor equipment or the piping in between. Most refrigerant leaks occur inside the indoor equipment on a component called the cooling coil.

Corrosion on copper coil

Corrosion on copper coil

Copper coils corrode mainly because of compounds in the air of the home. Outdoor coils, even though constructed of identical materials, do not experience this failure. My preference is aluminum.

American Standard ForeFront Air Handler All-Aluminum Coil

American Standard ForeFront Air Handler All-Aluminum Coil

We seldom have refrigerant leaks on these.

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Air Conditioner Maintenance

First things first –

If you don’t do anything else to maintain your air conditioner:

  • Change the air filter.
  • Maintain the condensate drain. Very few items are more likely to damage your home than a stopped up condensate drain.

Next on the list is outside. Clear any vegetation or anthills from around the unit. If you know where the condensate drain is located, make sure it is above ground and clear.

Air Filters –

There are two types available to the homeowner,

fiberglass Fiberglass Air Filter

Pleated Air Filter

and pleated.

Fiberglass filters are great if you get shot down behind enemy lines and need an air filter. All other times you should use pleated filters.

Drain maintenance –

Dad probably told you to pour bleach down the drain to keep it clear. It will keep the drain clear but also it accelerates corrosion on coils manufactured with steel and copper components. My preference is one (1) gallon city water ( it has chlorine bleach in it already) and maybe a 1/4 cup of bleach added. A properly installed system will have an access point installed at the indoor unit to allow the addition of water. Pour it through a funnel to restrict the rate of flow. Never pour bleach or water in a blocked drain; it doesn’t help. If you have a blocked drain, a wet-dry vacuum cleaner attached to the outlet will often clear up the problem. It that won’t do the job, you probably need a technician with more powerful tools to clear it out.

Why do drains stop up? –

You. Or more exactly, your skin cells. Between 30,000 and 40,000 of them fall off every hour. Beside pet hair, these cells are the major component of household dust. They are covered with bacteria. When swept into your air conditioner, they attach to the wet cooling coil and are washed into the drain pan. Inside the pan are ideal conditions for the growth of molds. It’s dark, it’s wet, all it needs to eat is bacteria. Air filters can keep this bacteria out of your cooling system.

Fiberglass air filters have large pores in their media. You can hold one in front of a book and read through it. Pleated filters have smaller pores catching smaller particles like skin cells.

A blocked drain can be cleared with a wet-dry vacuum but the blockage will probably recur. Cleaning of the internal condensate pan and addition of an algaecide by a technician is called for. If you don’t have one already, addition of a condensate float switch will turn off the air conditioner before the next blockage damages your floor or ceiling.

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