DIY Heat Recovery Ventilator ?

[Matt]

Either way, you're still paying to heat that air. The air you draw from outside will take a specific amount of energy to heat to room temperature, and that energy will come from your furnance/fireplace/heat pump/cookstove... whatever. Another minor problem is that it will take more fan than you think to push much air volume through any amount of dryer hose -- that stuff is fairly resistant to air-flow with all it's ridges and bends.

[Lance]

Matt's right. Any cold air brought inside and heated is consuming energy.

[bassman]

Well there ya go then, won't work properly. Thanks everyone, time to re-think.

As well as humidity control I would like fresh air circulating above the water.

[mark]

How much air you talking of moving?

If your talking to move the moisture evapourated would think you could get by with a reality low CFM. Just do what your thinking (vent hole opposite to let in the room air in) and could use a small in-line fan such Princess Auto carries to boost furnace ducts or fab something up with a small muffin fan.

[bassman]

Originally Posted by mark

How much air you talking of moving?

If your talking to move the moisture evapourated would think you could get by with a reality low CFM. Just do what your thinking (vent hole opposite to let in the room air in) and could use a small in-line fan such Princess Auto carries to boost furnace ducts or fab something up with a small muffin fan.

That is exactly what I am talking about, almost a whisper of air would do it I think.

[rdnicolas]

Originally Posted by bassman

That is exactly what I am talking about, almost a whisper of air would do it I think.

There are two general ways to remove mosture from air.
1) Use a dessicant dehumidifier
This uses a mosture absorbant silica gel to trap moisture from air
2) A (direct Expansion) DX Dehumidifier.
This has a refrigeration cycle that cools a heat exchanger below the dewpoint temperature of the air passing through it. The mosture will condense on the surface (like water condesning on a cold pint of beer) and drop out of the air.

Using a dehumidifier is probably the best way to reduce humidity without having to worry about heating transfered air from the outside. If you wanted to build something from scratch, you can build a glycol run around loop to run during the cooler days, however it wouldn't be effective during the summer (but your air transfer from outside idea might work in in its place)

[bassman]

Originally Posted by rdnicolas

There are two general ways to remove mosture from air.
1) Use a dessicant dehumidifier
This uses a mosture absorbant silica gel to trap moisture from air
2) A (direct Expansion) DX Dehumidifier.
This has a refrigeration cycle that cools a heat exchanger below the dewpoint temperature of the air passing through it. The mosture will condense on the surface (like water condesning on a cold pint of beer) and drop out of the air.

Using a dehumidifier is probably the best way to reduce humidity without having to worry about heating transfered air from the outside. If you wanted to build something from scratch, you can build a glycol run around loop to run during the cooler days, however it wouldn't be effective during the summer (but your air transfer from outside idea might work in in its place)

I am not as concerned about removing the moisture from the air as I am in removing the moist air all together, moving it outside. I have thought about a coil, still might do something like that too.

[ElGuappo]

If this is on an outside wall could you not run a 2" pvc pipe from inside your canopy throu the wall and out side. this would not allow any air into your house and alow the humiditty to go out. all it would need is a small fan for coaxing the humid air outside, and some sort of valve (butterfly/ball) to close this up in the winter.

[bassman]

Yes that is pretty much how I envisioned it, it won't need much movement at all.