DIY Heat Recovery Ventilator ?

[bassman]

I don't really need a HRV in the true sense for what they are designed for. I need something to deal with the possible humidity problems from a large tank.

This is my idea...

First my canopy will be sealed off from the air in the room in which it sits. Heat from my lights is dealt with in sump. So I am looking for a way to pull the hot, humid air from inside the canopy to the outside of my house.

I can easily punch a hole in the wall behind the tank, it's sits partially on a outside wall.

The only concern is replacing the air in the canopy as it's being pulled outside.

I could put a vent in the opposite end of my canopy and allow the air to be drawn in from the room but this is basically pumping my expensively heated air outside, not very energy efficient.

So I was thinking about having the air drawn in from outside as well as vented outside, of course in the winter this is going to be way too cold.

So.....

Why couldn't a person connect a pile of dry vent hose together (because they are fairly cheap) and snake them all over the ceiling in the basement thus allowing the new air time to warm from the house temperature? A person could even have the hose coiled up in numerous places to create even more "acclimation" time.

Thoughts???

[CRAP! Another Hobby]

So your concern is the humidity? What about some type of small de-humidifier built into the canopy? Not sure if there are any small enough to fit into a canopy, but might be worth the look. Who knows...maybe the rescued water from the dehumidifier can be filtered and fed back into the sump as your top-off water.

[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)

[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.