Helpful? 0

Is it cheaper to run a dehumidifier than an ERV in winter?

I am in zone 5A and I have a problem of excess humidity in my ICF home with no abnormal sources of moisture (5 occupants of a 2150 sft home with a full basement). This results in condensation on the wall of windows facing a pond on the north.

Since a dehumidifier will also dump heat into the home helping my all-electric furnace heat the home, I am wondering if it would cheaper to run the dehumidifier than to use an ERV to lessen the humidity in the home. I realize in the latter case, there's some loss of sensible heat that the electric furnace would then have to compensate for.

TIA.

Asked by Venkat Y
Posted Fri, 08/29/2014 - 16:17
Edited Fri, 08/29/2014 - 16:19

Tags:

5 Answers

Select your preferred way to display the comments and click "Save settings" to activate your changes.
1.
Helpful? 0

You still need some ventilation in winter, but for simply lowering the humidity during the heating season a dehumidifier would be more energy efficient overall, quite a bit more if you are heating with resistance elements rather than a heat pump.

Depending on your local climate and house construction you may need to pull the humidity down to 35% RH or lower to be protective of the house itself.

Answered by Dana Dorsett
Posted Fri, 08/29/2014 - 17:17

2.
Helpful? 0

Of course it would be even cheaper to lower humidity by using an efficient wood stove.

Answered by flitch plate
Posted Fri, 08/29/2014 - 20:09

3.
Helpful? 0

Sounds more like you need a HRV installed. Condensation is typical in a tight home with poor air exchange or lack of bathroom and kitchen ventilation. Dew point sensors installed in lieu of fan switches in the bathrooms can also assist.

http://www.dewstop.com/

http://www.venmar.ca/39-air-exchangers-e15-ecm-hrv-new.html#!prettyPhoto

Answered by Richard Beyer
Posted Fri, 08/29/2014 - 22:52

4.
Helpful? 0

Venkat,
Richard is right: if you are having problems with high indoor humidity during the winter, you want an HRV, not an ERV.

I disagree with Dana's advice. During the winter, lowering indoor humidity levels by ventilation is less expensive than lowering indoor humidity levels by operating a dehumidifier.

Answered by Martin Holladay, GBA Advisor
Posted Sat, 08/30/2014 - 06:43

5.
Helpful? 0

ICF homes take about one year to dry out initially. Also, if there is no capillary break, concrete walls can wick water up from below grade.

Answered by Kevin Dickson, MSME
Posted Sat, 08/30/2014 - 14:08

Other Questions in Energy efficiency and durability

Roof insulation

In GBA Pro help | Asked by Steven Clark | Oct 24, 14

Calculating how much air needed to even out temps for minisplit

In Mechanicals | Asked by Tom Frisch | Oct 23, 14

Will spray foaming my basement rot my sill plate?

In General questions | Asked by Chris McLean | Oct 24, 14

Window U-value comparison to wall R-value and window replacement

In General questions | Asked by Keith Miller | Oct 20, 14

Radiant Retrofit Best Practice

In General questions | Asked by mie asdfav | Oct 24, 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!