Humidity Control?

[hawk]

Originally Posted by BMW Rider

So even at 86% RH outside, you would gain significant drying of the inside air.

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With a HRV , but not with a bathroom fan when the exchange, is, already heated drier air going out for cold, more humid air coming in. I agree a simple bf will help in many situations but not for all.

[mark]

I'm with Ed on this (my weatherguy training), point to remember it's relative humidity.

Exhausting indoor moist air helps, all basically a HRV does is warm in the incoming air with the out going so you're not dumping (wasting) the heat outside. A bathroom just isn't a efficient way to do it.

[BMW Rider]

Originally Posted by hawk

With a HRV , but not with a bathroom fan when the exchange, is, already heated drier air going out for cold, more humid air coming in. I agree a simple bf will help in many situations but not for all.

The point I was making is that even though the outside air has a higher relative humidity, it actually has less moisture in it. The term relative humidity refers to the amount of moisture relative to the temperature of the air. Cold air can't hold as much moisture as warm air so even though it would seem to be more humid it actually is less so. Calgary can actually reach near to 100% relative humidy in very cold temperatures, but trust me, it is still really freaking dry.

It is irrelavant how you are making the air exchange, the colder outside air still has less moisture. The bathroom fan will work, its just that you'll be pumping all your expensive heat out with it.

[TheReefGeek]

Ok I went to the hardware store and got a bathroom fan, the tubing, and a 4" outside vent with a flap so that I dont lose heat when there is no air blowing.

Now, I found a humidistat, but that is to turn a humidifier on, I want the reverse. The only way I know to fix this is by installing a relay switch so that when the humidistat is on, the bathroom fan is off. Is there an easier way though?

I remember someone posted they have a bathroom fan with a humidistat, maybe they can chime in with how they did it?

[Delphinus]

You technically want a "dehumidistat" not a "humidistat" (they exist, the HRV's come with them).

[TheReefGeek]

Anyone know where these De-Humidistats exist? They were not at the Home Hardware or Rona I was at, I assume it will be a more specialty type store.

[Delphinus]

Afraid not. Maybe try a greenhouse supply or a heating (furnace) place and see if they can order you one.

I did find this one at grainger.com but wow .. not cheap
http://www.grainger.com/Grainger/wwg...632223&ccitem=

[TheReefGeek]

That is a bit pricey, a humidistat with a relay is about half the price, but a lot more work. Maybe I can find a cheaper one at a furnace place like you said.

[Paverdude]

I got mine @ sears

[crusty1]

thought I'd try to revive this thread rather than starting a new one, so it's kind of like a one stop shop for info on humidity issues and options to solve.

Has anyone using a dehumidifier or a bathroom ventilation fan experienced corrosion from the salt creep?

Any solutions to this problem?

Both my bathroom fan (went within weeks of install) and my dehumidifier (about a year before the humidity sensor coroded) have died due to salt creep/corrosion.