I have a Fantech HRV shr3205d. I am running it continuously on low in my house. I have a waterfurnace geothermal cooling system. The humidity level is staying around 60%. Once this summer, it went to 50%. I noticed that the drain hose that is connected to the drain pan on the HRV does not have any water/condensate running through it. The only time I saw water running through the drain hose was when the humidity level in my house fell to 50%. I have cleaned the aluminum core and filters. I have questions:

Should the HRV produce condensate during operation in the summer? I would think if the air being exhausted is cool and the intake air is warm, when the pass by each other, condensation should form? If condensation is not forming, is this an indication that there is something wrong with the unit or the aluminum cores? Could this explain the elevated humidity in my home?

I am running my geothermal at 68 and the house still has humidity levels above 60% and does not feel as cool as would be expected. Please advise.

Sincerely,
Frustrated!

Normally you should not expect condensation to occur in the summer months, but if you are located in the gulf coast area, with tropical humidity levels, then conceivably running the thermostat too low could cool the incoming air down to the dew point. Running the tstat at 68 could be problematic in such a climate, as the water vapor drive from outside toward the inside could result in condensation to occur behind the drywall inside. Then if you have a low-perm paint or vinyl wallpaper on the inside you haven't provided any way for the moisture to dry out.

Normally, condensation within the HRV would occur only in the winter months in a heating climate, when you have enough of a temperature difference to cool the outgoing air below the inside dew point, which likely would be in the mid to upper 40s. An HRV can be used in a tight house in winter to keep interior humidity from getting too high from human activity. In summer it can't normally be used for that. Don't run the HRV at any higher fan setting than you need to maintain interior air quality.

If you are running your heat pump in cooling mode now, then a humidity problem would mean that the unit is not running long enough to dehumidify the house. That could be because the outside air is humid but not especially hot, so that the heat pump doesn't have much cooling to do, or it could mean that the unit is quite oversized for the cooling load in the worst of summer. If you don't have any settings to run the unit in "dehumidification mode" then you could think about a standalone dehumidiffier for the shoulder seasons. Whether the house is cool enough is a matter of reading a thermostat. If the tstat is set at 68 but the house won't cool down to that, then either the tstat is faulty or there is something wrong with the unit. Umm, you don't have the tstat set in heating mode, do you?

Is there a need to bring in outside air 7/24/365?