Long-time lurker, new poster...hello, all!
First full winter (moved in 3/2012) in our new home....
NE Ohio, 1500 sq.ft (each of 2 levels), super tight ICF construction, R60/foam ceilings, Carrier Infinity system air to air heat pump/ERV, EnergyStar rated, blah, blah, blah
...and our problem is not keeping it warm (we actually heated it to mid-60's inside temps last Feb. with a 1500w milk house heater prior to heat pump install), but de-humidifying it in cooler (30's to high 20's so far) weather.
I'm treating this as a separate issue from fresh air control, which I think we have handled OK, including slight positive pressure in the house (.12/83 cfm in... .08/70 cfm out per labeling on the ERV). We have just been leaving the ERV set on LOW during our waking hours till this point, but the humidity is climbing into the 50% range.
The Infinity controller has an AUTO setting for the ERV which according to the manual should run the system to achieve a pre-selected humidity level. I played with that some over the weekend, and for most of the time, the ERV was on HIGH and the furnace fan was on at least medium.
Now to the specific question.. Is it more efficient energy-wise to use the ERV for humidity control in this manner (and suffer the hit of heating all that incoming air), or should I revert to ERV for replacement air control only and use a 50 pt dehumidifier I already have to control the moisture content in the house?
An associated thought.....although the dehum uses 500 watts when on (thanks Killawatt!), some of the energy actually heats the house (warm air coming off the unit when running), and there's no indoor/outdoor air exhange.
Thanks to anyone who takes the time to comment on this very specific question, or any other comments.