“Basics of IAQ”

1. “Basics of IAQ”

2. What is IAQ? IAQ (Indoor Air Quality) is an ever-growing concern to the population and is a far reaching subject that we as comfort specialists must get a better grasp on in the very near future. With our customers being bombarded with products that make claims to do everything from cleaning 99.9% of all dust in the air to killing all airborne germs and viruses, our customers look to us to make sense of it all.

3. Who Regulates IAQ? The information in the industry is sporadic at best; so, we must turn to the agencies that monitor it for guidance. The Environmental Protection Agency (EPA), American Medical Association (AMA), and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) are such agencies we depend on for the best possible information.

4. How do you control IAQ? • What we read from the EPA is that there are three main areas of concern for IAQ, they are: • 1) Source Control • 2) Ventilation • 3) Filtration

5. What are they? Source control eliminates the problem or reduces the problem at its source. Ex. Dehumidification, removing cleaning products from under the sink. Ventilation brings in fresh air from outside to dilute the stale air inside the tightly constructed home. ERV, HRV, or Fresh air duct Filtration cleans the circulated air that is in the home. Ex. Filters, UV, Catalyst

6. What is Relative Humidity? Humidity is measured in Percentage of Relative Humidity (%RH) or the amount of moisture in the air compared to how much moisture the air can hold at any given temperature. The warmer the air is the more moisture it can hold before producing condensation (dew point).

7. Humidity is “Latent Heat” High humidity makes us uncomfortable in the cooling season (summer). We all know that. However, high humidity can also make us feel warmer in the heating season as well. Remember that moisture in the air is a form of heat (latent heat). Remember as the temp drops the amount of moisture in the air stays the same but the Relative Humidityincreases.

8. What are other impacts of Humidity? If the Relative Humidity is too high, we can have moisture problems. Fungus and mold can grow, dust mites thrive, and a host of other undesirable conditions can occur. If the Relative Humidity is too low, we lessen those detrimental effects but then can have static electricity, skin disorders, nose bleeds, etc. - another group of issues we must consider. The ideal RH for a home is 35% - 50%.

9. What else is in the air? • Pollutants include the very materials from which the home is constructed. • Examples are: insulation, plywood, particleboard, foam sealants, caulk, paints, carpets and glues. • All of these products, when exposed to higher temperatures or humidity, will off-gas at higher rates. • Off-gassing is when these products let off VOCs (Volatile Organic Compounds) into the air we breathe.

10. So how do we control VOCs? • The recommended methods for controlling these VOCs are to: • 1. Remove products from the living space (source control). • 2. Ventilate. An air change does not represent a complete change of all air in the home. The actual percentage of a home's air which is exchanged in a period depends on the airflow efficiency of the enclosure and the methods used to ventilate it. The actual amount of air changed in a well mixed ventilation scenario will be about 63% after 1 hour. In order to achieve equilibrium pressure, the amount of air leaving the space and entering the space must be the same. ASHRAE has a standard of 35% air changes per hour.

11. So how do I Ventilate a home? • HRV, Heat Recovery Ventilator • For dry climates • ERV, Energy Recovery Ventilator • For humid climates • Fresh air duct tied to the return that may be controlled by %RH or outdoor Temperature

12. What else is harmful in the home? One pollutant that is common in modern homes is carbon dioxide (CO2). CO2 is produced by cigarette smoke, candles, unvented cooking products, unvented fire logs, leaky chimneys, idling cars in attached garages, and wood burning fireplaces or stoves or a damaged gas or oil furnace.

13. Are there any Standards for IAQ? ASHRAE has set 2 standards that you should become familiar with. Standard 52 covers Filtration in homes and offices. Standard 62 covers the ventilation for homes and offices.

14. How big is all of this stuff? Mold is a large particle and viruses are very small

15. How are filters rated? The large dust captured by the filter was rated as Average Arrestance Efficiency. If a filter captured 90% of the large dust, over a given time, it was given a 90% Arrestance Efficiency. The small dust captured by the filter was rated as the Average Dust Spot Efficiency. If a filter captured 30% of the fine dust, over a given time, it was given a 30% Dust Spot Efficiency. One of the most common ratings today is the MERV. Minimum Efficiency Reporting Value

16. So how does a MERV compare?

17. So what do I recommend? First make sure the filter is sized right and second make sure it will move the air (CFM) properly. Lennox has chosen to use a MERV 12 as its target minimum for recommendations.

18. Will the filter be enough to clean the amount of air in a home? All of the air in your home should be completely circulated through your system in 8-20 minutes. 2000 Sq ft x 8 ft ceiling height = 16,000 cubic ft of air. 3 ton A/C moves 1200 CFM 16,000 / 1200 = 13.3 minutes completely circulates the air.

19. Circulation Problems • Humidity high or low • Not cooling or heating in home • Dust in home • Drafty rooms • Sweating ductwork • Moisture around grills • Musty odors • Home pressure changes when blower turns on