Healthy Home - Fresh Air Supply Systems
I think it’s safe to say we are now living a post-covid world or at least an altered one that has many different new normals. My optimism says we have gotten a lot of good things out of this pandemic, including a better work/life balance with the flexibility of working from home. That means we are spending an even greater amount of time inside our homes breathing air and is why indoor air quality (IAQ) is more important to your overall health than ever.
One of the focuses we have at Dilworth Homes is making our homes a healthier place to live by using materials that have a low VOC off-gasses, installing water filtration systems, air sealing certain areas of the house with spray foam and installing fresh air supply systems.
A modern air-tight home needs mechanical fresh air ventilation to keep its occupants healthy. This is a deep dive into how to get fresh air into your house through a controlled, filtered system no matter what kind of climate you live in.
HVAC (Heating Ventilation & Air Conditioning) systems in your home commonly just recycle the air inside your house and have a filter on the return vent that you should change out every 3 months or so. Side note; using the subscribe feature on Amazon to deliver air filters to your house is great to keep your air clean and remind you to change them out. However, unless you open a window, you are never getting fresh air inside your home. When you open the window, you are bringing in all kinds of pollen, dust and pollutants from outside and into the air you breathe.
Today’s building code has a minimum requirement (in California at least) that we have a “whole-house fan” running at all times sucking the air out of the home creating a slight negative pressure inside your house. This helps bring in fresh air when you open a window or from all the small leaks your house has in your walls, floors and roof. Not a great practice if your home is built with materials that have VOCs inside the structure. Surprise, everything has VOCs in them! Didn’t you read the warning label on everything that you buy in California that causes cancer?
Fresh air supply systems are commonly used in commercial buildings and in the past have been uncommonly used in residential homes. The food and the medical industry use fresh air supply to positively pressure certain rooms and keep contaminated air from getting inside the space, creating a clean air environment. Hospital rooms use this positive air pressure method to keep patients in different rooms from breathing the same air. On the contrary, when a restaurant’s kitchen or science lab has a room with smoke, contaminants or chemicals they don’t want to get out, they suck the air out and create a negative pressure in that space to control where that air goes.
In our homes, we apply the same commercial air pressure principles and techniques using today’s latest technology so our houses are the healthiest home a consumer can buy.
The commercial systems for air control are fairly complicated, but the concept is simple; pull filtered, fresh air from outside to create positive pressure in your house to keep out airborne contaminants like allergens, chemicals, viruses, bacteria, and radon out. Contaminants that can make you and your family ill over a long period of time.
In rooms like your garage, we suck air from inside to outside to create a negative pressure and keep the garage air out of your home which is where high VOCs things are often stored including your car.
Here are 3 easy methods and products we have found to bring fresh air into your home depending on the climate you live in:
Energy Recovery Ventilation (ERV) System or Heating Recovery Ventilation (HRV) System: Both ERVs and HRVs are somewhat new to mainstream home construction, and can often be confused with a commercial system. We like the Panasonic Intelli-Balance 200 or 100. The 200 model is brand new with an easier install in smaller places, additional custom controls. This system should be used in hot and cold climates because it uses the stale exhaust air to preheat or cool the incoming fresh air depending on the outside temperature. This reduces the energy required to bring outside air to ambient room temperature so saves some money on heating and cooling bills. The system cost around $1,000 plus installation. There are several manufacturers for residential ERV & HRVs, but look for the models that have a built-in filter (Merv 13 or better) with variable fan speed controls for both the intake and exhaust fans. That way you can put a positive pressure inside your house with a higher speed for the intake than the exhaust. This system is on most of the time and has automatic system-off controls. Its power consumption is pretty low with brushless DC powered fan motors that Panasonic is known for.
Fresh Air Supply Fan: If you live in a climate like we do in Culver City, California, then you don’t really need an ERV or HRV system since it is almost perfectly 75 and sunny everyday. To keep it simple, we like the Panasonic WhisperFresh Select Fresh Air supply fan. It’s about $500 plus install and comes with built-in Merv 13 filter and controls for 50-150 CFM, temperature and humidity. So, on those occasional times when it’s hot or it rains, it will turn off automatically. This system is also on all the time unless one of the custom controls turns it off, but draws a max of 0.41 Amps when it’s on at 150 CFM.
Fresh Air Ventilation Damper (FAD) Systems: These systems are about as basic and cost effective as you get. It is tied into your house’s HVAC system on the air return side and can utilize the system’s air filter. The FAD has an electronically controlled damper system so you can control when you want to bring in the fresh air. In addition, you can implement this into your house’s dehumidifier if you have one on your system.
The California Energy Commission Title 24 requires fresh air ventilation systems in all new construction and renovations. The code minimum currently for fresh air is a whole house fan running 100% of the time (a bath fan usually) that sucks air out of the house and brings fresh air in through windows and cracks in the home. We think that code minimum is a poor method and to upgrade to a mechanical fresh air system is well worth the money-to-health impact. Having a healthy home is so important to the longevity of your family's health and it should start with fresh air pushing out stale air to improve indoor comfort and health.
About the Author
Jonathon Dilworth is the Principal of C&D Partners, a real estate development and investment company that specializes in value-add multifamily investing in the Western United State and for-sale spec single-family-home development in Culver City, CA.
