Most of us spend the bulk of the day indoors, and a lot of that time at home. The EPA notes that indoor levels of some pollutants can be two to five times higher than typical outdoor levels. Your heating and cooling system moves all of the air in the house, which makes it the best tool you have to manage it.
What's in the air
Indoor air quality, or IAQ, comes down to a few things:
- Particles. Dust, pet dander, pollen, smoke and dust mites from carpet and bedding. Cincinnati's spring pollen season pushes a lot of this inside every time a door opens.
- Gases and chemicals. Volatile organic compounds, or VOCs, from cleaning products, paint, new furniture and flooring. Cooking adds its own mix.
- Moisture. Too much and you get mold, musty basements and more dust mites. Too little and you get dry skin, static shocks and gaps in wood floors.
- Combustion byproducts. Gas furnaces, water heaters, stoves and fireplaces all have to vent properly. Carbon monoxide is the dangerous one, and you can't see or smell it.
Newer and remodeled homes are built tighter to save energy. That helps the utility bill, but less fresh air leaks in, so whatever is produced inside stays inside longer.
Why humidity matters so much here
Greater Cincinnati swings between humid summers and dry winters. The EPA recommends keeping indoor humidity below 60 percent, ideally between 30 and 50 percent. In July a basement can sit well above that. In January a furnace-heated house can drop well below it.
Summer humidity is partly an equipment question. An air conditioner removes moisture as air passes over the cold evaporator coil. An oversized unit cools the house quickly and shuts off before it has run long enough to dry the air, leaving the house cool but clammy. Proper sizing helps, and a whole-house dehumidifier can handle what's left. In winter, a whole-house humidifier on the furnace adds moisture back in a controlled way.
What your HVAC system can do
Good indoor air starts with controlling the source, then filtering and ventilating what is left.
- Better filtration. Filters are rated by MERV. A MERV 8 catches dust and pollen. Filters in the MERV 11 to 13 range catch finer particles, including some smoke and bacteria. Denser filters also restrict airflow more, so a thick media filter cabinet is often a better choice than forcing a dense one-inch filter into a slot built for something lighter. A technician can measure static pressure to see what your system can handle.
- Sealed ductwork. Leaky return ducts in a crawlspace, attic or garage pull dusty, damp air straight into the system. Sealing them helps air quality and efficiency.
- Ventilation. An energy recovery ventilator brings in fresh air and exhausts stale air while holding on to much of the heating or cooling energy.
- Clean coils and drains. A dirty, wet indoor coil or a clogged drain pan can grow mold and spread it through the ductwork.
- Carbon monoxide detection. Every home with gas appliances or an attached garage should have working CO alarms on each level and near bedrooms.
When you change a filter yourself, shut off power at the furnace switch or breaker first.
If your home feels stuffy, dusty, damp or too dry, or someone in the house has allergies that flare up indoors, call JM Mechanical at (513) 667-8484 or request service online. We'll look at filtration, humidity, ductwork and ventilation and tell you what will make a difference.