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Douglas, HVAC Technician
Category: HVAC
Satisfied Customers: 3089
Experience:  Manufacture Rep for Major Brand, Technical Trainer, NATE
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We have a vanEE HRV. It is installed on a dual energy furnace

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We have a vanEE HRV. It is installed on a dual energy furnace (heat pump/gas) with a humidifier. There are only two controls for the HRV unit, the 20 min bathroom timers and the black button on the unit itself that controls the fan speed (low, high, off). My questions is: Is the fan supposed to be running all the time? I thought that was supposed to cycle on/off to balance with the humidifier. It is currently running all the time and we can hear the fan through the duct work in the master bath.
Which control do you have? Do you have the bathroom timers also?

Customer: replied 7 years ago.
There are only 2 controls (see original question) bathroom timers and the push button on the unit itself. The only thing we can control from the thermostat is the furnace fan, temp, energy source and humidity percentage. I had been told that the humidity percentage would control the humidifier and the HRV unit would then balance automatically based on the humidity setting.
The button on the unit has 3 choices. Low, high and off.

The XXXXX XXXXXght will leave the fan on low speed always and only go to high when the bathroom timers are engaged. High (green LED)all the time is just that and the bathroom timers are moot. If it is off, (LED off) the bathroom timers of course will bring it on.

It would then depend on whether your installer interlocked it into the furnace and how. If he did, when the unit comes on, it would also bring on the furnace blower.

Check the LED and see if it's blinking, this can indicate an error depending on whether the LED is blinking amber or green.
If he wired it to control humidity it will depend on if it's wired forward or reverse acting. If your humidity setting is lower than the actual humidity, raise the setting to see if the fan shuts off, and visa versa
Customer: replied 7 years ago.
I guess my question wasn't clear enough. I understand the settings on the unit for the fan speed, but I'm trying to figure out from a technical standpoint (and also from a comfort perspective) how are we supposed to have it set. Is the unit supposed to be on all the time or is it better to have it cycle on and off?
I see, sorry.

If you are using the HRV to simply make up fresh air to the home when evacuating a bathroom, the 20 minute cycles are fine. This is best from an economic standpoint. However, if you are trying to keep fresh air supplied to the home, then leaving it on in the low fan mode is the preferred method.

There are additional controls. For instance on my home, I have the master control which has the unit come on for 20 minutes out of every hour and it also has a polution sensor (dont ask me what it measures as a polutant) but I have noticed when my daughter is done in the bathroom with her hairspray and perfume, the polution sensor takes over and runs the system until it is clear. This is a nice feature but requires the additional control.

That is not to say you need to have that control installed, but it would give you another option. Comfort is subjective and to each his own, but if I didnt have the 20 minute on and 40 minute off control, I would certainly run it constantly on low and let the bathrooms run on high when the timer is pressed. I dont have the bathroom sensors, just the main one in the hall. I wish I did because if someone doesnt turn it on and off when they use the restroom my only hope is that either the polution sensor or the timing works out.

The HRV simply takes the heat out of the exhuast air and puts it into the fresh air in winter and visa versa in summer.
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