Our friend and customer, Robb, just moved into his beautiful new home in Louisiana. It’s on a quiet bayou and it’s the dream house he and his wife have wanted for years. In winters, it can get clammy there, but the house is tight and well-insulated so he stays warm. In summers, the air conditioner runs 24/7, of course. But the AC hasn’t been able to handle the humidity, says Robb.
‘Do I need a ventilator?’ he asks. ‘And if so, what kind?
There is some understandable confusion about the topic. Heat Recovery Ventilators (HRVs) or Energy Recovery Ventilators (ERVs) are designed for different climate zones. The difference is that HRVs recover some of the heat that would be exhausted. For most of the country, an ERV will do the job of removing humidity and introducing fresh air into a well-sealed home.
A Home Needs to Breathe
We hear this all the time: A house needs to breathe. Whereas in Robb’s grandpa’s day, the chief concern was keeping the heat outside the building and minimizing humidity, now the attention has turned to the amount of fresh air introduced into the home— an equation known as CFM, or cubic feet per minute.
One example is the Rheem PROTECH ERV (http://www.comfortup.com/rheem-protech-energy-recovery-ventilator-erv-200-cfm). This whole-home ventilator replaces 200 cubic feet per minute (CFM). There are other units available such as this 100-CFM Heat Recovery Unit: http://www.comfortup.com/rheem-protech-heat-recovery-ventilator-hrv-100-cfm), also made by Rheem, that change air at the rate of 100 CFM.
There are standards for how much fresh air is needed in the home, depending on the size of the home, number of occupants and other factors. The rule of thumb is that a 2,000-square-foot home with three bedrooms and four occupants should have a CFM of 50. That number will be affected by other factors— such as home construction and the climate. (Calm, muggy weather like Robb gets for most of the year, means less air flow in and out of the home.)
If you want to learn more about ventilators in general, check this paper from the University of Kentucky: https://www.bae.uky.edu/energy/residential/guide/guidehtml/guidep32.htm.