Indoor air quality

Fresh air for a healthier home

These videos from the Northwest Clean Air Agency show different ways to ventilate homes to maintain indoor air quality. They are useful resources for anyone who designs, builds, inspects or lives in a structure.


Intro & segment 1 - Why ventilate?

New houses these days are more tightly sealed, so it’s even more important for occupants to control the fresh air ventilation system inside the home. Natural ventilation, such as opening windows, may not be ideal as it can introduce contaminants such as pollution and pollen and increase energy costs.


Segment 2-Exhaust only systems

This system is the least expensive and uses the simplest technology. This system pulls air in using intentional air inlets called trickle vents.


Segment 3-Integrated systems

This system uses a fresh air intake located away from pollution sources. It pulls outside air into the suction side of the furnace, which then circulates air to the rest of the house. This is the most expensive system to operate.


Segment 4-HRV/ERV systems

Heat-recovering ventilation and energy-recovering ventilation (HRV/ERV) is a balanced system that despite the initial cost can be the most effective, efficient, and inexpensive system to operate on a daily basis. This system uses two small quiet fans; one to draw fresh air in from the outside and the other to remove stale indoor air.


Segment 5-Installation & inspection

Before planning and installing any type of ventilation system, you’ll need to determine how much fresh air needs to be delivered. Ventilation standards are measured in CFM, cubic feet per minute, based on the square footage of the house and the number of rooms. The video describes how to get the most efficient ventilation rate with each different type of system.


Segment 6-Upgrading existing homes & credits

This describes how to improve ventilation strategies in older homes, which may rely on uncontrolled air leakage for air exchange. Studies show that of natural air leakage, 40% comes from crawlspace and another 17% comes from attached garages, both of which aren’t commonly associated with healthy air. Remediation techniques include sealing air leaks and ensuring adequate flow rates for localized fans.


Protecting your home from radon

According to the U.S. Environmental Protection Agency (EPA), radon is the number one cause of lung cancer among non‐smokers and the second leading cause of lung cancer overall, responsible for about 20,000 lung cancer deaths every year.

Radon is an invisible, odorless, and tasteless gas that comes from the breakdown of uranium inside the earth. It causes no immediate health symptoms. Simple test kits can reveal the amount of radon in any building. In most buildings, levels of radon can be reduced with easy and affordable venting techniques. Homes built on a concrete slab or homes with a basement may also be at a higher risk for radon gas.

Radon levels are believed to vary throughout Clark County, with higher levels in areas bordering the Columbia River. Because of these varying radon levels, Public Health encourages all residents to get their homes tested. Test kits are available at most home improvement stores.

Radon: Have you tested your home?
Radon: frequently asked questions