Humidifier in crawl space with flexible ducts?

[toyzrme]

Hi -
I'd like to install a whole-house humidifier, but I live in NC, and I have one of those AC/gas-pack systems where the HVAC unit it outside, up against the house, connected through the wall to a small plenum (22x16x18) inside my crawlspace as a distribution block for flexible ducts. I think there is enough room to mount a humidifier there, but I have a few questions:
- where would my evaporator coil be in this case? Is it in the outside unit, or in that little bit of a plenum in the crawlspace, meaning I can't attach the humidifier there?
- what are the implications in low temperatures? My crawlspace is uninsulated, but I have put down plastic on the dirt floor for moisture, and keep the vents in the foundation closed. I have a thermometer down there, and it looks like it keeps about 18 degrees above the outside temp (so far), so it would be ok until a really cold snap. I know there are wrap-around heat tapes for pipes I could use on the water supply line, but what about the humidifier itself? Would there be enough heat from the furnace running periodically to keep the humidifier warm? (I could insulate around the humidifier if that would help)
- would a drainless model be better for me, since (as I understand it) they leave no standing water that could freeze? (eg Aprilaire 400)
- how long can the bypass duct be? I'd have wrap mine around a bit to get it there, but should still be under 6-8 feet total
- what do I do for sensing that the HVAC is running? Can I add a current-sensing relay anywhere on the 220v supply line to the AC/gaspack unit?

I also have a second zone system in the attic for the second floor, but I assume this is even less attractive (b/c it would get colder).

Are there any decent options for me? Or am I SOL?

Thanks!

[Jay11J]

To be honest, you are kinda SOL..

You could do it. but it just too much work to "Protect" the unit from freezing. And IF you sold the house and the next home owner don't know about it.. then they are in for a mess.

Also if it's down in the crawl space, it maybe forgotten about, and also if there was problem, you won't see it right away.

Be best to get those stand alone unit and put it in your living room, or near a larger return vent.

Even in the attic, it's a big no no.

[toyzrme]

Thanks - those were my thoughts, too.

One thing I should add is that the crawlspace is on a slope, and the HVAC plenum is near the lowest/bottom corner, so if there was a leak, there would be no damage to the house (as for the furnace, well......).

I was just hoping someone would know of a system that was designed for such a situation. All of my neighbors have the same setup - it's very common around this area.

I do have an in-house humidifier, but I have to put 3-6 gallons of water *a day* into it - a pain, and it tells me we need the humidity <g>.

Does anyone know of system that could be installed in-line with one of the register ducts, or the cold-air intake/return (eg one that's inside the house)?

Another thought was that I could move the water valve (solenoid) up to the water heater where it would stay warm, with an anti-siphon valve so that the line would drain when the solenoid shut off. If I insulated all of the tubing, the hot water would keep it warm enough to drain all the way through. Any little bit of moisture that remained should melt quickly the next time the hot water flows through.

Is a mist/sprayer-type humidifier appropriate for this situation?

Or am I trying too hard? <g>

[Jay11J]

I would never suggest the spray type for anywhere.

To me, the spray may over spay, then you have wet ductwork.... rust..... leaks...

Packaged units are not found around here in homes, just on bussiness..

Ed may know what you can do for your set up since packaged units are found more often in the south.

[Ed Imeduc]

Well to start here Go to http://aboutsavingheat.com/crawlspace.html

and

[url]http://www.advancedenergy.org go to buildings here

I would close up the crawl space and put insulation on the walls also a small register in the duct to let some air out and a small return there also. All of this should start to give you more humidity in the home. On the ground there you want a 6 mil poly one the ground aver lap it 2' and tape all seams. on the wall 2"or 3"polystyrene up to the joist line.
Id try all this first. If you do put in a humidifier you can usa a A50 relay on the blower wires and this will tell the humidifier to come on that the blower is running.
Any more ????? come on back in this same post..

my .02 cents

ED ;)

[toyzrme]

Thanks.

FYI there is good (thick) insulation under the floor (between the joists). So will insulating the crawlspace still help that much with heat in the house?

My crawlspace is 13ft at one end, 6ft at the other, so not cheap to insulate, and would take a lot to seal - think it would still be useful?

Plus, I'm concerned about covering the back of the siding - I don't want a vapor barrier there, as it would trap moisture and rot the siding, would it not? (I have at least some siding - 1ft-10ft - on 3 sides of my crawl)

And I would be worried about 'air-conditioning' my crawlspace, esp. pulling all that air into the house (eg humid outside air).

Thoughts?

[rtimg]

I live in southeastern VA and have a gaspack/crawlspace configuration too. The hardwood floors around the registers were starting to dry out soon after we moved in. When I started to do some research, I found out pretty much the same thing- there are no great options for a humidifier app with this config. I contacted the manufacturer of the gaspack unit but they were absolutely no help whatsoever.

I ended up having a Skuttle spray mist unit installed, but I now regret the decision. A steam generator with fan assist system looks like a much better option (Honeywell HE420A1009). I will likely replace the Skuttle sprayer if its performance remains unsatisfactory. (Such a great feeling to waste $$$ and effort, is it not??)

As to freezing, you likely live in the same transitional climate area that I do- relatively mild temp extremes. Freezing in the crawlspace should be relatively rare, and the heating element in the steam humidifier would provide some protection. The mounting orientation would also afford some thermal transfer. I assume that you already have water pipes in your crawlspace.

You could always rig a light bulb adjacent to the humidifier unit and set a thermostat switch to turn on and keep the unit warm when the temp does drop below freezing in the crawl.

Good luck. If you have since figured all of this out please let me know what I should do.

rtimg