January 9, 2018
Winter is typically the time of year when we start to pay more attention to indoor air quality. This is because we spend more time indoors and try to save money and energy by sealing off our homes to the cold air outdoors (aka winterization).
While energy efficiency is something we encourage, there are real dangers associated with airtight homes. In fact, the Environmental Protection Agency has deemed indoor air quality one of the top 5 environmental risks to public health.
Exhaust fans, usually located in kitchens, bathrooms, and laundry rooms, expel stale air and moisture that builds up in the vicinity. While they do a pretty good job at getting rid of stale air, they are exhaust only, meaning they don’t have a way to pull in fresh air from the outside.
Instead, exhaust-only “spot” ventilation tends to create negative pressure inside of the home, resulting in air coming in through cracks and gaps in the home. This can potentially pull in unwanted radon and other soil gases that we don’t want in our homes and businesses.
A potential solution to exhaust ventilation negative pressure buildup is to install a supply-only mechanical ventilation system. This will bring in fresh air, allowing the home to depressurize. Supply-only ventilation can be hooked up to your forced air system, allowing fresh air to get dispersed via your duct system.
This can help reduce the amount of radon and other contaminants from entering the home. One problem that may develop is the introduction of high humidity into the home, especially in areas where you already have a moisture/condensation problem.
For nearly all homes, especially if they are tighter and more energy-efficient, we recommend a balanced ventilation system that has been specifically designed for the building.
Balanced ventilation combines exhaust and supply ventilation into one system. When contaminated and moisture-laden air leaves the home, fresh air enters. With a balanced ventilation system, you can choose where the exhaust air is drawn, where fresh air comes from and where it is delivered to.
Typically, exhaust ventilation is installed where the most moisture and pollutants are generated, such as bathrooms, kitchens, and artist/hobby spaces. Every stove and bathroom should have a high-quality exhaust fan that vents to the outside.
You can choose whether or not the supply air is point-sourced or ducted. If the fresh air is brought in through the duct system, it is typically delivered to the most-used areas of the home, such as living rooms and bedrooms.
One reason why people don’t ventilate their homes as much as they should is because they don’t want to lose the precious heat or air conditioning that they are spending precious money on. That’s where a heat recovery ventilator comes in. Installed into the ventilation system, the air-to-air heat exchanger uses the conditioned air that leaves the house to help precondition the air coming in.
Source: Popular Mechanics
HRVs are typically used in colder climates, but they can also remove heat from incoming air during the summer months. Something called an energy recovery ventilator (ERV) is used in hotter, more humid climates.
They work pretty much the same, but an ERV helps transfer the humidity from incoming air to the stale, outgoing air. This helps maintain ideal humidity levels in the home, which is especially important for indoor air quality. ERVs can also bring humidity into the home depending on the humidity level inside the home and the humidity level of the incoming air.
Learn more indoor air quality solutions for winter, and don’t forget to ventilate!
Service Champions is known for trustworthy, on-time heating and air conditioning service throughout the East Bay, South Bay, and Sacramento areas.