How to Create a Healthy Environment, Step 2: Continuous Mechanical Ventilation
Homes now are being built tighter than ever before, especially if you are buying an Energy Star 3.0 Certified Home or an NAHB (National Association of Home Builders) Certified Green Home. In these certified homes, builders work very hard at sealing all the areas where air can leak in or out of the house. They use newly designed house wraps, windows, doors, sealing caulks, and other building materials to create a seal that will optimize the energy efficiency. This reduces drafts in the house. But, pollutants trapped in the airtight house can cause health problems for the occupants. It can also cause problems with the structural integrity. Because of this there are also requirements for the ventilation in a “green” home.
Some of the pollutants found in airtight homes are mold, mildew, pollen, dust mites, pet dander, viruses, and bacteria. These biological pollutants thrive in a humid environment.
Sources of Moister in a Home:
• Tubs
• Showers
• Cooking
• Washing Machines
• Dish Washers
• Fish Tanks
• Plumbing Leaks
• Defective Gutters
• Inadequately Waterproofed Basements
• Human Breathing
A continued build up can affect those with allergies or asthma. It can also lead to deterioration of structural supports and walls from the inside out.
As part of the natural aging, decomposition, or curing of the building materials, carpets, furniture and many other items in the home VOC’s (Volatile Organic Compounds) are released into our homes. This is called “out-gassing”.
Other Sources of VOC’s:
• Hair Spray
• Paints, Lacquers, Finishes
• Oven Cleaners & Other Cleaning Solvents
• Pesticides
• Smoking
• Lead, Mercury, Cadmium, Arsenic (Found in Lumber)
• Asbestos (Found in Older Homes)
• Calcium (Collects in Humidifiers and becomes Air Borne)
VOC’s can be odorless and colorless. Prolonged exposure can cause immune system damage, headaches, dizziness, nausea, muscle spasms, and multiple chemical sensitivity.
It is impossible to eliminate all the pollutants found in a home. Eliminating old chemicals, purchasing Low VOC paints and chemical free cleaning products can help. Proper ventilation in the home will also combat these issues. An ERV (Energy Recovery Ventilator) can help with the mechanical ventilation in an airtight home. An ERV is used to remove stale, moist, polluted air and replace it with fresh outside air. It runs all the time to provide continuous ventilation to a home. As part of a continuous ventilation system vents are often placed by bedroom and bathroom doors to ensure air movement throughout the house even when the doors are shut. Exhaust fans will not work by themselves. They only exhaust air causing a negative pressure in the home, and they
don’t bring fresh air back in.
Choosing an ERV is important. Because it runs continuously it needs to be quiet and energy efficient. It can also filter, dehumidify, and temper the incoming air. Tempering helps bring the outside air temperature closer to the temperature inside the home. This is done through a special filter. Tempering helps keep a steady more comfortable environment in the home winter or summer.
Knight West Homes puts a Panasonic Whisper Green ERV in every house. Not too long ago a wild fire burned in a Saratoga Springs Community. Homeowners were evacuated. Upon returning to their homes, Knight West Homeowners reported having no smoke
damage or smell in their homes, neighbors who didn’t build with Knight West had to bring professional cleaners in to get rid of the smoke smell in their homes. This is due to the air tight construction and the Panasonic ERV.