HRV

[sprink]

building a new house and I will be installing a heat recovery ventilator. the returns will come from the 4 bathrooms, the kitchen, and possibly the laundry room. the hrv will be 150 cfm. my question is do I also need bathroom exhaust fans, or would the hrv be sufficient. I would wire it to come on from any bathroom switch if it was not already running.

[trouble time]

The local building inspector can answer your question. It changes from Provence to Provence and I would guess from State to State. When I built by house I was planning on putting one in anyways and then the inspector said I needed one.
I did not install any fans in the bathrooms, but the windows open. Our code says one or the other.
Mine is wired in with the controls that come with it. A Humidity sensor in each bathroom. The unit runs low speed most of the time until the sensors in each bathroom pick up high humidity and then it switches to high speed until the humidity level is where I want it.
good luck.

[teddy bear]

building a new house and I will be installing a heat recovery ventilator. the returns will come from the 4 bathrooms, the kitchen, and possibly the laundry room. the hrv will be 150 cfm. my question is do I also need bathroom exhaust fans, or would the hrv be sufficient. I would wire it to come on from any bathroom switch if it was not already running.

Rated at 150 cfm results in 100 cfm actual at best. Divide by 5 is 20 cfm per spot. A good bath/shower exhaust is +75 cfm. Why not focus on the main shower/tub bathrooms. For get about the laundry room, the clothes dry exhaust +100 cfm. The kitchen has a hood. Also make the ducts larger because they are longer from the farther baths. Just a thought.If you go with the small ducted many exhaust points, use a good bath fan in the key baths. Make provisions to operate the HRV whenever the windows are closed and the home is occupied year around. Homes breath less during calm warm weather than during cold windy weather.
Don't forget a good heavy duty dehumidifier the Santa Fe Advance in the basement to provide <50%RH throughout the home.
Regards TB

[sprink]

thanks for the info. the house is being built with ICF's so a HRV is pretty much a necessity anyway. i'll just have to suck it up and install the bath fans also.

[enb54]

building a new house and I will be installing a heat recovery ventilator. the returns will come from the 4 bathrooms, the kitchen, and possibly the laundry room. the hrv will be 150 cfm. my question is do I also need bathroom exhaust fans, or would the hrv be sufficient. I would wire it to come on from any bathroom switch if it was not already running.

We also have an air to air heat exchanger (HRV) with independent ducting to two bathrooms, kitchen and basement so that we don’t have mould buildup problems in the winter when the place is basically sealed up pretty darned tight. After several years, also installed bathroom fans into the HRV ducting as the moisture was not being evacuated fast enough with the HRV only.

[sprink]

I like the idea of piping the bath fans into the hrv duct. that will save me a lot of ductwork,and more importantly, wall penetrations.I'll still need the HRV running when the bath fans are running to help with what will be a long exhaust run. Thanks.