Mold is Not Cool, But Hope Your A/C Is!

There have been a few days with temperatures in the 80's already this spring. Soon, the NC heat and humidity will settle in for the summer and air conditioners will be working hard to keep up.

The proper sizing, design, installation and maintenance of your HVAC system is essential to help control indoor mold. Problems in any of these areas can cause issues with humidity levels or condensation, both of which are key moisture sources for mold growth in your home.

Your HVAC system and its associated ductwork also provides a vehicle to transport mold spores throughout your home once a problem starts. A little preventative maintenance now will help ensure that your systems operates effectively throughout the summer and does not contribute to indoor mold growth.

Remember that HVAC contractors are busiest during peak summer heat and winter cold periods. Schedule a preventative maintenance check of your cooling system now to ensure you are ready when the temperatures start to rise.

The Energy Star website offers these tips for homeowners to ensure your HVAC contractor is keeping your cooling system operating at peak performance:

1) Clean evaporator and condenser air conditioning coils. Dirty coils reduce the system's ability to cool your home and cause the system to run longer, increasing energy costs and reducing the life of the equipment.

2) Check the central air conditioner's refrigerant level and adjust if necessary. Too much or too little refrigerant will make your system less efficient increasing energy costs and reducing the life of the equipment.

3) Clean and adjust blower components to provide proper system airflow for greater comfort levels. Airflow problems can reduce your system's efficiency by up to 15 percent.

4) Check thermostat settings to ensure the cooling and heating system keeps you comfortable when you are home and saves energy while you are away.

5) Tighten all electrical connections and measure voltage and current on motors. Faulty electrical connections can cause unsafe operation of your system and reduce the life of major components.

6) Lubricate all moving parts. Parts that lack lubrication cause friction in motors and increases the amount of electricity you use.

7) Check and inspect the condensate drain in your central air conditioner, furnace and/or heat pump (when in cooling mode). A plugged drain can cause water damage in the house and affect indoor humidity levels. Air Matters reminds you that this can lead to mold growth.

8) Check controls of the system to ensure proper and safe operation. Check the starting cycle of the equipment to assure the system starts, operates, and shuts off properly.

And don't forget to change your air filters regularly!

Air Matters LLC has performed mold testing services in the Raleigh NC area since 2002. The owner, Renee D. Ward, has over 25 years of safety and environmental experience and holds both her Bachelors and Masters degrees in engineering. Renee is also a member of the American Industrial Hygiene Association and the Indoor Air Quality Association. You may contact Air Matters at (919) 961-2221 or info@AirMattersMoldTesting.com.

How Does Your Home "Stack" Up?

There is constant air movement through your home. There are generally three types of forces that move air through a house: HVAC equipment, wind, and the "stack effect".

The stack effect is when warm air moves upwards in a house. Since we can't create a vacuum in our homes, new air has to come into the home to replace the air that has escaped to normalize the pressure.

Although the stack effect occurs in both the summer and the winter, the effect is usually greater in the winter due to the temperature differential. In the winter, cracks and openings throughout the building shell allow the pressure difference between indoor and outdoor spaces to drive air out of the top floor and to suck air in through the first floor.

In the summer, when indoor air is cooled, the reverse occurs; however, because the temperature difference between inside and outside typically isn't as great as it is in winter, the stack effect isn't as great either.

Whatever the season, the best way to remedy the stack effect in most houses is by minimizing gaps between indoor and outdoor spaces. Think about the places where new air is able to enter the house.

According to the US Department of Energy, the following areas are responsible for a large majority of air leakage that occurs in the average American home:


Ceiling, Walls and Floors – 31%
Ducts – 15%
Fireplace – 14%
Plumbing Penetrations – 13%
Doors – 11%
Windows – 10%
Fans and Vents – 4%
Electrical Outlets – 2%

These figures provide you with the most important areas to target for air sealing. However, a home energy audit will pinpoint the exact locations of air loss and assess your entire home’s energy consumption and waste, and recommend ways to improve your home’s energy efficiency.

Air Matters LLC has performed mold testing services in the Raleigh NC area since 2002. The owner, Renee D. Ward, has over 25 years of safety and environmental experience and holds both her Bachelors and Masters degrees in engineering. Renee is also a member of the American Industrial Hygiene Association and the Indoor Air Quality Association. You may contact Air Matters at (919) 961-2221 or info@AirMattersMoldTesting.com.

I’ve done a whole lot of research on sealed crawlspaces the past few weeks. I have read everything from product literature provided by contractors who install the systems, to building science articles, to ASHRAE standards and studies. Here are a few of the highlights of what I have learned:

What is a Sealed Crawlspace?

A sealed crawlspace is also referred to as closed, conditioned, or semi-conditioned. The basic design has no vents, insulated foundation walls, a heavy plastic and/or concrete liner on the floor, and an insulated and weather-stripped access door.

A small amount of conditioned air is delivered to the crawlspace area from the HVAC system creating positive pressure in the crawlspace. The positive pressure prevents air from the crawlspace being drawn into the duct work and delivered to the living space. Crawlspace air remains in the crawl not in the living areas.

What are Some of the Benefits Claimed?

Sealed crawl space systems are said to reduce or eliminate many common problems, such as:

• Mold or moisture damage in the crawl space or living area
• Musty odors
• Condensation (“sweating”) on air conditioning ductwork or equipment
• Condensation on insulation, water pipes, or truss plates in the crawl space
• Buckled hardwood floors
• High humidity throughout the house
• Insect infestations
• Rotting of wooden framing
• Increased load on air conditioning and dehumidification systems

Many studies I read documented average energy savings from 15-18%. Another resource also pointed out that many of the crawlspace upgrades qualify for the 15% federal tax credit energy program.

The two most common disadvantages I came across were the cost and the ability to retrofit existing crawlspaces.

Are Vented Crawlspaces Really a Problem?

There was a study performed by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) involving fungal sampling indoors, outdoors, and in the crawlspaces of 45 homes with traditionally designed vented crawlspace. Air leakage testing determined the connections between the house, crawlspace, and HVAC systems located in the crawlspace.

Results indicated that most of the crawlspaces contained liquid water, moisture vapor, and fungal spores. The houses also contained measurable holes between the crawlspace and the living space, with both natural and mechanical air movements across these openings.

This led to a measured transmission of fungal spores from the crawlspace to the living area. High moisture levels in vented crawlspaces in the Southeastern United States were linked to higher mold counts inside the living space.

There are also a number of excellent scientific articles available on www.BuildingScience.com that explain why traditional vented crawlspace designs may not be the best option for humid climates.

Want More Information?

Advanced Energy is an independent non-profit corporation that is governed by a Board of Directors appointed by the governor of North Carolina and the member utilities. The company was set up and still operates to work with member utilities on energy efficiency and conservation projects. There is a lot of useful information regarding crawlspaces and other topics in the knowledge library of their website at:

http://www.crawlspaces.org/

Air Matters LLC has performed mold testing services in the Raleigh NC area since 2002. The owner, Renee D. Ward, has over 25 years of safety and environmental experience and holds both her Bachelors and Masters degrees in engineering. Renee is also a member of the American Industrial Hygiene Association and the Indoor Air Quality Association. You may contact Air Matters at (919) 961-2221 or info@AirMattersMoldTesting.com.

Carolina Wattbusters Crush Wolfpack Kilowatters

The Environmental Protection Agency (EPA) recently announced the winners of its first ever National Building Competition. Participants were challenged to measure their energy use and reduce wasted energy with support from the Energy Star program. Their energy performance was tracked from September 1, 2009 through August 31st, 2010.

From a building over 100 years old in New York City to an elementary school in the mountains of Colorado, a shopping center to a hotel, and many types of buildings in between, these teams from around the country worked hard to slim down their energy use.

Together, the 14 competitors reduced their energy consumption by over 44 million kBtu’s, saved more than $950,000 on their utility bills, and reduced their carbon dioxide emissions an equivalent of the electricity used by 600 homes for a period of one year.

Contestants were judged on the percent reduction achieved in their Energy Use Intensity, or EUI. A building’s EUI is calculated by taking the total energy consumed in one year (measured in kBtu) and dividing it by the total floorspace of the building.

For example, if a 50,000-square-foot school consumed 7,500,000 kBtu of energy last year, its EUI would be 150. A similarly sized school that consumed 9,000,000 kBtu of energy last year would have a higher EUI (180) to reflect its higher energy use. Generally, a low EUI signifies good energy performance.

The winner was a building from right here in the Triangle! Morrison Residence Hall on the campus of UNC-Chapel Hill went from a starting EUI of 213 to a final EUI of 137, a 35.7% reduction. Morrison is a 10 story, 217,522 square foot, 850 occupant residence hall constructed in 1965. It was renovated in 2007 to provide central heating and air conditioning to all rooms and to install solar hot water panels.

Second place went to the Sears in Glen Burnie, MD and the third place finisher was the JC Penney in Orange, CA. Another triangle campus dormitory – Tucker Hall at NC State University – was in the running and finished in 8th place. Tucker dropped their EUI from 172 to 154, a 10.3% reduction.

For more information on the contestants, strategies used to reduce energy consumption, or to apply for the 2011 contest (applications must be received by February 25th, 2011), visit www.energystar.gov/buildingcontest.