Indoor Air Quality Solutions

If you suffer from asthma or sensitivities to allergens (such as mold) or other irritants, Air Plus may be able to help you breathe a little easier.  How can a mechanical contracting and engineering firm help your medical condition?  By addressing the quality of the air you breathe.   Your doctor will agree that the most effective way to limit your symptoms is to limit your exposure.  Although you may not have control over your work environment, you do have control over your home environment – that’s where we can help.

Simply put, most homes in the Lowcountry are not capable of maintaining acceptable indoor air quality^†.   Many have moisture-related problems unique to the region and/or have deficient air conditioning systems; most, however, were simply designed without regard to indoor air quality and do not provide the fresh air ventilation, filtration and humidity control necessary for sensitive occupants.

If you are serious about the quality of the air in your home, Air Plus can help.  After conducting an interview to discuss your individual sensitivities, we will survey your home to determine if there are any site-specific concerns contributing to poor air quality.  We will then develop a strategy to address point-source contaminants and improve overall air quality in your home via proper ventilation, filtration and humidity control.   Finally, Air Plus is available to install necessary systems and equipment, providing you with a turnkey indoor air quality solution. 

† ASHRAE (The American Society of Heating, Refrigerating, and Air-Conditioning Engineers) defines acceptable indoor air quality as: air toward which a substantial majority of occupants express no dissatisfaction with respect to odor and sensory irritation and in which there are not likely to be contaminants at concentrations that are known to pose a health risk.

Humidity Control

  "It’s not the heat, it’s the humidity"

Nowhere is that more true than in the Lowcountry.  High humidity within your home or light commercial building is not only uncomfortable; it is the primary condition leading to mold and overall poor indoor air quality.  Unfortunately, most residential and light commercial HVAC systems (air conditioners) are designed to maintain temperature, not humidity.  In many parts of the country, systems designed to operate based on temperature alone work fine; in the Lowcountry, many do not.  There are a host of conditions that contribute to elevated humidity levels including infiltration, poor/inadequate HVAC design, site conditions and moisture-laden crawl spaces.  For absentee owners, interior humidity can be particularly problematic if air conditioning systems are "set back" for extended periods.

If high humidity is a problem in your home or business, Air Plus can help by providing you with a professional evaluation to determine sources of moisture and develop a strategy to maintain acceptable interior humidity levels.  If corrective measures are required, Air Plus is available to install necessary systems and equipment, providing you with a turnkey humidity control solution.  Call us today at (843) 225-6265 to find out how we can help.

 

Home owners/buyers should be aware that humidity control (or moisture removal) is only a secondary benefit of standard air conditioning (i.e. moisture is only removed when the thermostat is calling for cooling). Although currently accepted HVAC load estimating methodologies attempt to maximize the moisture removal capabilities of standard air conditioning, it does on ensure satisfactory results, particularly in warm humid climates. Humidity control can be improved with controls, the use of variable speed air handlers and the use of multi-stage compressor systems. Additionally, whole-house dehumidification systems can be installed to precisely control humidity independent of the air conditioning system. Those with mold allergies, asthma or other respiratory concerns should be particularly aware of the benefits of interior humidity control.

Location: Leader Lane, Hidden Cove, Mt. Pleasant

High humidity and poor HVAC design resulted in mold on the ceiling and cabinets in this Mt. Pleasant home.

 

Location: Commercial Building, Kiawah Island

High humidity coupled with cold interior temperatures resulted in substantial mold growth behind the wallpaper in this meeting room on Kiawah Island.

 

Location: South of Broad, Charleston

Uncontrolled humidity in this South of Broad home was causing the paint to literally fall from the walls.  Mold was also a problem as the humidity levels were routinely in excess of 70%

 

Hardwood Floors

In general, cupping is caused by a disparity between moisture above and below the floors (i.e. higher moisture below the floors than above the floors.  Unfortunately, cupping is often just one sign of a more serious problem - excessive moisture in the crawl space that could cause serious structural damage to your home, or worse, create mold-related health concerns for you and your family.  There are numerous causes for elevated moisture below the structure and it is important that the situation be diagnosed correctly, if a long-term solution is to be implemented.

Air Plus can evaluate your hardwood floors and develop a realistic strategy to control moisture and keep your hardwood floors flat.

Legends Terrace, Snee Farm, Mt. Pleasant, SC - These Kitchen hardwood floors were cupping due to elevated crawl space moisture exacerbated by the use of under-cabinet registers and congested ductwork.

White Point Court, James Island, SC - Hardwood floors throughout this James Island home were cupping due to elevated subfloor moisture largely due to interior temperature control.

Harbor Place, James Island, SC - The subfloor under these hardwood floors was saturated causing the floors above to buckle.

Millbrook Court, Longpoint, Mt. Pleasant, SC - Widespread cupping of the hardwood floor in this Mt. Pleasant home was caused by elevated crawl space moisture.

Clearspring Drive, Ocean Neighbors, James Island, SC - Although the crawl space of this James Island home appeared dry, the elevated relative humidity (as compared to that on the inside) was enough to cause these floors to cup.

Monico Drive, Townhomes of Beaumont, Mt. Pleasant, SC - The moisture content of the slab below these floors was high enough to cause these hardwoods to buckle.  The townhouse had experience a plumbing-related flood, but the floors (including the floors in the adjacent unit) were not allowed to dry out sufficiently prior to reinstalling the hardwood floors.

Healthy Air

What is in Your Air?

 

Mold – Mold is the #1 threat to the indoor environment. All mold is allergenic and some can be toxic. According to the EPA, mycotoxins, produced by mold during metabolic phases and as a defense mechanism, can cause illnesses ranging from an allergic reaction to cancer.

 

Dust Mites – Dust mites are the #1 allergen-producing organism in the home. Dust mites are microscopic spiders that feed off dead skin cells. A standard mattress can contain 1 to 2 million dust mites. Dust mites are not airborne so they cannot be filtered out of the air.

 

Pet Dander – Animal dander is dead skin cells, hair follicles, dried saliva and urine. Most animals produce a protein, glycoprotein, to which many people are allergic.

 

Bioaerosols – Any pollutant in the air which is created by a plant or animal is considered a bioaerosol. Pollen, rag weed, mold and fungi are all bioaerosols. Bacteria and viruses are also within this classification.

 

VOC – Volatile organic compounds are vapors or gases that are carbon based. There are hundreds of volatile organic compounds in indoor and outdoor air, many of which have adverse impacts on human health.

 

Carbon Monoxide – CO is a colorless, odorless and tasteless gas byproduct of inefficient combustion and/or vent backdrafting of fuel burning appliances. CO inhibits the blood’s ability to absorb and distribute oxygen. Symptoms include fatigue, dizziness, nausea, flue-like symptoms and death

Why is Healthy Air Important?

According to the American Lung Association more than one-third of Americans have an allergic sensitivity to at least one common substance. They go on to say that asthma rates in the United States have increased 75% over the past twenty years and asthma among children has risen 160%.

Although the causes of allergies and asthma are largely unknown, the triggers are easily identified and, with the proper attention, can be controlled. Beyond eliminating specific sources of contamination, acceptable indoor air quality has three key components – ventilation, humidity control and filtration.

VENTILATION

Energy saving construction techniques may cause contaminants to be trapped in the home and become concentrated. Ventilation is required to dilute these pollutants. According to ASHRAE, the nation’s most recognized authority for ventilation and air conditioning, the air in your home should be exchanged a minimum of 8 times per day. In our climate, however, the humidity brought in with that outside air must also be considered.

HUMIDITY CONTROL

Dust mites, the most common allergy producing organism found in the home, and mold, the greatest health risk in the home, can be restricted through humidity control. High humidity not only supports dust mites and mold, but can also increase the release of VOC’s from building materials. As you can see from the chart below, a humidity level between 40% and 50% is the ideal range to control allergy producing organisms in the home.

FILTRATION

Major advances have been made in the area of filtration, both media-type and electronic. Combined with humidity control and fresh air ventilation, high efficiency filtration is the third key element to improved indoor air quality. Those with allergies, asthma or other respiratory concerns should be particularly aware of the benefits of high efficiency filtration.

Caution should be used, however, when using products such as pleated filters. Readily available and marketed to improve air quality, pleated filters can actually make things worse if the duct system is in poor condition. Since air will take the path of least resistance, more air is pulled in through duct leaks with a pleated filter. If the duct system is located in an unconditioned attic, or worse, a crawl space, "bad" air being pulled into the house can actually increased.

Breathe Easy

If you suffer from asthma or sensitivities to allergens (such as mold) or other irritants, Air Plus can help you breathe a little easier. Your doctor will agree that the most effective way to limit your symptoms is to limit your exposure.

"Once an allergy has been identified, the next step is to decrease or eliminate exposure to the allergen. This is called environmental control. Evidence shows that allergy and asthma symptoms may improve over time if the recommended environmental control changes are made."

National Jewish Medical & Research Center

Simply put, most homes in the Lowcountry are not capable of maintaining acceptable indoor air quality^†. Many have moisture-related problems unique to the region and/or have deficient air conditioning systems; most, however, were simply designed without regard to indoor air quality and do not provide the fresh air ventilation, filtration and humidity control necessary for sensitive occupants.

The Environmental Protection Agency (EPA), the American Lung Association and the American Society of Heating Refrigeration and Air-Conditioning Engineers (ASHRAE) agree that proper ventilation, humidity control and air filtration are vital for healthy indoor air. Properly designed and installed systems address each of these important issues.

If you are serious about the quality of the air in your home, Air Plus is here to help. After discussing your individual sensitivities and concerns, we will conduct a diagnostic assessment of your home to determine if there are any site-specific, building or system issues contributing to poor air quality. We will then develop a strategy to address point-source contaminants and improve overall air quality in your home via building envelope improvements, moisture management, proper ventilation, filtration and humidity control.

† ASHRAE (The American Society of Heating, Refrigerating, and Air-Conditioning Engineers) defines acceptable indoor air quality as: air toward which a substantial majority of occupants express no dissatisfaction with respect to odor and sensory irritation and in which there are not likely to be contaminants at concentrations that are known to pose a health risk.

Crawl Space Assessments

Although commonly incorporated into Lowcountry residential construction, moisture problems are common in naturally vented crawl spaces.  Excessive moisture in the crawl space is responsible for mold and decay, results in cupped hardwood floors, invites termite activity and is a major contributor to poor indoor air quality.  If air conditioning ducts are located in the crawl space, health effects are amplified as mold, moisture and other crawl space contaminants are readily drawn into the living space.  Unfortunately, many of the common methods used to address crawl space moisture, such as increasing ventilation by adding vents or installing fans, can and usually do make the situation worse.  Excessive crawl space moisture needs to be properly diagnosed and realistically addressed.

If excessive moisture has been discovered in your crawl space or you believe excessive moisture has resulted in one of the items mentioned above, Air Plus can help by providing you with a professional evaluation.  Since input from the owner is crucial, we will start by conducting an interview to discuss the history of the situation and other pertinent information such as operating conditions within the home.  We will then perform an investigation to determine the source or sources of excessive moisture and develop a strategy to effectively manage those sources.  If corrective measures are required, Air Plus is available to install necessary systems and equipment, providing you with a turnkey moisture reduction solution. Call us today at (843) 225-6265 to find out how we can help.

 

Location: Castle Pinckney Drive, James Island, SC

These pictures were taken in a crawl space on James Island.  There was an effective vapor barrier in place, but two fans had been installed and were constantly moving moisture-laden air over the cold floor, thereby increasing the amount of condensation forming on the floor joists and resulting in fungal activity.  In addition to wood destroying fungus that will ultimately result in structural damage, black mold was visible at numerous air conditioning duct penetrations.

Location: Lyttleton Street, Byrnes Downs, Charleston, SC

These photos were taken in the same crawl space.  The top two show that the floor sytem original to the house is rotting away.  Two years ago, the new joists seen in the bottom right photo were installed but nothing was done to address the moisture problem.   The new joists are covered with condensation - its only a matter of time before these joists look like the ones they replaced.

Location: Cherokee Rose, Dunes West, Mt. Pleasant

This crawl space isn't even a year old and the joists are already covered with fungi.  This one was caught early enough to correct the situation before major damage or health issues evolved.

Location: Berkeley Drive, Moncks Corner

This Moncks Corner home was purchased from the owner's parents two years before these pictures were taken.  The parents never experienced problems, but when the son moved in and lowered the thermostat setting to 70 degrees, the floors began to buckle.  By the time I surveyed the home, the floor system in the crawl space was covered with mold and wood destroying fungus. 

Location: Burningtree Road, Country Club II, James Island

This house was inspected by the termite company in February, just months before these pictures were taken.  Inactive fungi was noted on their report  but no concerns over seasonal moisture problems were mentioned.  This condition, overlooked by the termite company, is causing serious structural damage and just imaging the quality of the air in the living space above.   

 

Closed Crawl Spaces

What’s All the Talk About?
 

If you don’t know what a closed crawl space is, you might want to do some research. If properly designed and installed, closed crawl spaces WORK – that’s what all the talk is about!

• No cupping floors (moisture is equalized above and below the floors)
• No wood decay/rot (wood stays dry, 10-15% wood moisture content)
• No mold (no excess moisture, relative humidity is maintained at 50-60%)
• And termites hate dry wood

Building New?  Renovating?  Have an Existing Ventilated Crawl Space?  Call Air Plus today to find out more about the advantages of an Engineered Closed Crawl Space (ECCS)

Why an Engineered Closed Crawl Space?

• Confidence – that your closed crawl space will be designed and implemented by Air Plus, a SC registered engineering firm specializing in residential/light commercial moisture control.

• Confidence – that all relevant issues will be explored and addressed including site conditions, drainage, humidity, crawl space layout, interior temperature control, duct location, etc.

• Confidence – that our engineer will work closely with the installation crew during the construction phase and provide valuable technical assistance and consulting services.

• Confidence – that common mistakes will be avoided – our experience will help avoid common mistakes encountered with crawl space moisture control.

• Confidence – that you are installing only what you need.  Air Plus will design the system right for your application and nothing more.

• Confidence – that you will receive documentation detailing the scope of work and verification that the project was installed as designed and meets all applicable codes.  The documentation provided by Air Plus is a valuable asset in the event of a future sale and shows that the project was designed and installed in a professional manner.

If you would like to learn more about Engineered Closed Crawl Spaces, call today. (843) 225-6265

 

This crawl space located in Snee Farm in Mt. Pleasant was covered with mold and wood destroying fungi.  After removal of the insulation and cleaning the floor system, the crawl space was closed and dehumidified with commercial-grade equipment.  The crawl space is now maintained at a relative humidity of 50-60%, well below that necessary to support fungal activity.  Closed crawl spaces such as this one also prevent hardwood floors from cupping and since there is no longer mold growing on the floor system, provide for a better environment in the living space above.

 

CSA Remote Humidity Controller & Alarm

Humidity Controller and Alarm with Remote Sensor for 24 Volt Systems

GLS Engineering developed the CS/A to provide an accessible user interface and high humidity alarm for controlling and monitoring dehumidification equipment located in a crawl space, attic or other limited-access location.

Programming and Installation Instructions

Contractors:  To learn more about the CS/A Controller and how to Order, please contact Louis Schweers, PE at Louis@glsengineering.com

 

• SC/A Humidity Controller/Alarm with Remote Sensor

• Specifically designed for Crawl Space Applications

  • Sensor located in crawl space

  • Controller/Alarm located in Interior/Garage

• Adjustable Humidity Set Point and Band (Differential)

• Adjustable Alarm Set Point and Delay

• Audible and Visual Alarms (with Reset)

• Adjustable Circulation Mode

• Three Alarms

  • High Humidity

  • Float Switch (Optional)

  • Water Sensor (Optional)

• Output relays on all alarms for integration into third party monitoring systems

 

 

But I like it Cold!

The following text is from a letter written to a Mt. Pleasant Air Conditioning Contractor in response to his concerns about oversizing equipment for a customer in order to maintain a low interior temperature and the implications of the low thermostat setting.

November 17, 2005

Re: Residential Equipment Sizing and Operating Temperatures

Dear Mr. M______,

Thank you for requesting information concerning some of the generalities associated with residential equipment sizing and interior operating temperatures. Specifically, you requested information on the implications of sizing residential equipment to maintain an interior temperature of 70º at an outdoor design temperature of 98º. You also requested information concerning the implications of maintaining an interior temperature of 70º in general. The following information should help you identify many of the concerns with non-typical equipment sizing and/or temperature control.

To provide some background information, typical design conditions for the Charleston, South Carolina area include an interior temperature of 75º with a relative humidity of 50% and an exterior temperature of 92º dry bulb / 77º wet bulb. These "standard" design conditions have been developed by the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) and are incorporated into ACCA’s (Air Conditioning Contractors of America) Manual J Load Calculation Procedure. The design conditions reflect average comfort conditions and take into account the limited moisture removal capabilities of standard residential cooling equipment.

Although it is certainly conceivable that the summertime exterior temperature in Charleston can exceed 92º, ASHRAE warns against sizing equipment to meet the cooling requirements during the most extreme conditions. Rather, ASHRAE recommends that in addition to temperature control, cooling systems be sized to provide adequate comfort dehumidification control as well, particularly in humid climates such as coastal South Carolina. To accomplish this, they recommend the use of an outdoor design temperature for which only a small percentage of predicted seasonal temperatures are expected to exceed. Since standard residential equipment only removes moisture when the compressor is running (in an attempt to satisfy the thermostat), this method provides for improved dehumidification via longer run times and improves part-load performance.

Assuming an exterior design temperature of 98º, the resulting equipment size would be larger and the dehumidification capabilities of a standard system for the given space would be significantly reduced, particularly during less-than-peak loads. Loss of humidity control due to "short-cycling" of the unit could reduce comfort levels and provide conditions suitable for fungal activity (mold). The system may also experience higher temperature swings as the larger equipment would quickly cool the space and drop the temperature to below the thermostat setting before the thermostat sensed the change. Although the dehumidification capabilities (and temperature swing) could be improved with the use of variable speed (variable speed air handler and 2-stage compressor) equipment, the addition of whole house dehumidification via add-on equipment (such as manufactured by HealthyAir and ThermaStor) would be recommended in this scenario. Additionally, although variable speed equipment would be recommended, air distribution within the structure may be adversely affected. Although the duct system would be designed for maximum flow at the peak load, operationally, the system would run at a lower fan speed a significant portion of the time, possibly affecting the even distribution of supply air.

Although the loss of dehumidification capabilities with oversized equipment can be address via proper equipment selection and add-on equipment, an interior design temperature of 70º has implications of its own that must be considered. First, the discharge temperature associated with 70º return air (50º-55º) may be problematic. In a scenario where humidity is not taken into account, supply registers and adjacent surfaces (walls, furniture, etc.) could be quickly cooled to below the dew point temperature of the interior air and result in condensation or isolated elevated humidity sufficient to support fungal activity. Even with sufficient interior humidity control, lesser degrees of isolated condensation and/or high localized humidity levels might be possible in moisture prone areas or where air flow was impeded. Assuming interior humidity is addressed, other issues must also be considered.

Lower interior temperatures are often associated with crawl space moisture problems. If a home is maintained at very cool interior temperature, the temperature of the floor system will often fall to below the dew point of the air in the crawl space and condensation will occur on the subfloor, joists and insulation. Similarly, the colder ducts (due to the supply temperature running through them) will be more likely to experience significant condensation and result in colder floors adjacent to the ductwork, thereby increasing the condensation on the floor system. In addition to general fugal activity, if condensation is allowed to form on the wood structural components, wood-destroying fungus will become active and damage the structure. My experience is that naturally ventilated crawl spaces with interior temperatures maintained at 70º to 72º suffer from significant, widespread moisture problems. One method that has been used successfully to address these concerns is to seal and dehumidify the crawl space, thereby lowering the dew point temperature and limiting the amount of moisture available to condense on cold surfaces. This can be readily accomplished with new construction or retrofit to an existing crawl space as well.

Although to a lesser degree than in a naturally ventilated crawl space, the potential for condensation on ductwork and mechanical equipment located in a ventilated attic is also increased with colder discharge temperatures. Condensation in wall cavities has also been associated with colder interior temperatures. Since batt insulation is often installed with the vapor barrier to the warm-in-winter side, if the back side of the drywall falls to below the dew point due to cold interior temperatures, condensation or elevated humidity (and ultimately fungal activity) will occur within the wall cavity. This situation is exacerbated where supply air blows directly onto a wall or in overcooled, confined spaces such as a bathroom. Although various options are available for existing structures, for new construction, sprayed-in-place closed-cell foam insulation has been successfully used to provide a satisfactory thermal and moisture barrier in walls with similar circumstances. Additionally, the same insulation can be used in the attic to provide a semi-conditioned space, thereby limiting condensation on cold ductwork and mechanical systems.

Finally, it should be noted that, in general, buildings are designed with the expectation that they will be maintained at, and have mechanical systems designed for, the conditions outlined at the beginning of this letter. Any deviations, particularly those that have the potential to promote condensation within the thermal envelope, crawl space or attic, should be thoroughly evaluated by the design professional.

I hope this general information has been helpful. Please do not hesitate to contact me if you have any questions or if I can assist you in any other way.

Sincerely,

 

Louis Schweers, PE

GLS Engineering, LLC

 

Duct Cleaning???