Basement dehumidification options

[S_Elliott]

I have a basement that gets humid in the summer when it's hot. Seems to be fine in the winter. The basement shares a heat pump with the main floor. I've used a portable dehumidifier for the last 2 summers. Now I'm finishing the basement and want a built-in system. Is it possible to use the existing heat pump for dehumidification control or should I be looking for a separate dehumidification unit.

The heat pump is an American Standard Heritage 18 with variable speed air handler.

[ga-hvac-tech]

I do not know where you are (what area you live in), however I did basement work most of the 1990's.

HVAC in a basement has some unique details to understand. Personally, I would contact a few HVAC guys that can demonstrate experience with basements. They can explain the details to you and make recommendations.

As a rule of thumb (which mostly do not work); NO, you really should not plan to use part of the capacity of the main floor system for this application... unless you find someone that really understands airflow and zoning.

[S_Elliott]

I'm about 30 miles SE of Seattle. I made a few phone calls to HVAC contractors but have not been able to find anyone I'm comfortable with. Recommendations welcome.

[Carnak]

dehumidifiers are for musty basements in the summer

[DavidPJ]

I'm not a professional but I can tell you what works for us on our just over 1 year old house. The basement has radiant concrete floor heat for the winter. The rest of the house has heat pumps. The HVAC contractor installed a heating/cooling zone in the basement with vents and returns off the main system. The purpose of the zone was to provide airflow in the basement and to dehumidify in the summer. The basement zone has its own thermostat, and in the summer I set it to provide just a little cooling for dehumification purposes. Works great.

[wahoo]

As previously discussed, you could zone your system and it would condition the basement. However you may not get enough "run time" in basement zone to lower the humidity much, so I'd still keep the stand-alone de-humidifier and leave it connected in the furnace room. If you have a variable speed air handler, use the continuous air flow option, and this will help a bunch.

[DavidPJ]

As previously discussed, you could zone your system and it would condition the basement. However you may not get enough "run time" to lower the humidity much, so I'd still keep the stand-alone de-humidifier and leave it connected in the furnace room. If you have a variable speed air handler, use the continuous air flow option, and this will help a bunch.

Forgot to mention, as wahoo suggests, I have a variable speed air handler and have the VisonPro thermostat set to automatically and radomly turn on/off the fan.