attic humidifier needed
I am an EE and an avid do it yourselfer. I just finished an addition in Maryland. I put in a second Heat Pump system (American Standard, electric, airtight, variable speed, 13 SEER) during the project. I removed the existing heat pump ductwork from the basement system that used to feed the second floor. I installed a new system in the attic with all new rigid and insulated ductwork. Every room on the top floor has a seperate supply and return, and there is a common return in the hall. The system itself works fine.
My big question is: what is the best way to get Humidified air up there? I don't want stand alone and tacky room humidifiers, I don't want an in wall stand alone unit, and above all I don't want it to freeze in the attic. The cost of a steam system is prohibitive as well as dangerous (in my opinion), so that leaves only evaporative. I have been searching relentlessly for a system made for attics and I can't believe it, but no manufacturer has an evaporative type that is good enough for attic installation. I started to design one myself and came up with a pretty darn good idea of a centrifugal type that I can connect to the hallway return duct that might work. Although I would have to buy a bunch of seperate parts (24v - 110V ac relay, make a special overflow pan and run lines through to the bathroom on the other side of that wall as well as do some custom sheetmetal work.
I was just wondering how would you do it? Anyone ever run up against this issue before?
Is there some reason that you can't use a humidifier such as an Aprilaire in your attic? Get the model 760a (now 700) with the forced air operation that installs on your main supply duct. I think that you don't want it in your return duct because of condendsation problems and subsequent rust. See: http://www.aprilaire.com/
Last fall I was going to install one myself but I found a great installed price from Burtonsville Fuel in Burtonsville, MD.
You'll need a water supply line (of course) and a drain in the attic.
[This message has been edited by BillyG (edited September 06, 2001).]
I forgot to address the issue of freezing in the attic. You can probably insulate the supply line enough and run it near a heated duct to help prevent freezing. It will take a lot of insulation. You may want to use a hot water line for the supply.
You could build an insulated box around the humidifier unit with at least two (in case one burns out) small light bulbs inside the box, such as nite light bulbs. Or get a thermoelectric heater. You need to do it carefully so it will not be a fire hazard.
One option for running the supply line would be to run it inside insulated PVC pipe with some type of heat source (low wattage heat tape?) inside the pipe. You're a EE so you can figure it out.
The more difficult problem will be the drain line. Perhaps you should drain back into a drain line inside the house.
When necessity is the mother of invention, I just had to do it myself. I designed, built, tested, then installed a solution to the attic humidifier problem. I designed a system that humidifies the upper floor of my Northeatern home through the attic system automatically, using commercially avaliable parts. There was not one single manufacturer willing to do it, nor did any have an idea on how to do it well. My subsystem is now in its second year of running and it works perfectly. I can adjust the humidity to whatever level that I wish, with no problems.
The system consists of some standard relays, switches, humidistat, and a specific type of humidifier. I only wish that I had the money to patent it and my three other inventions.
Actually I did not run any water lines to the attic. That is what is so neat about the invention I came up with. I have figured out a way to eliminate all the problems that everyone here has described.
As I am writing this, I am comfortably enjoying an adjustable (I like mine at 55%) humidity level in my upstairs office from my attic heat pump system (that's right a heat pump system). No more sore throats when I awaken, no dryness, no filling up portable units, no spores. mold or mildew, or dust from atomizers. It just plain works. I have perfect humidity, with a completely maintainable, clean, and automatic system. the only maintenance is cleaning the resevoir once per year in the spring (not that there is standing water in the system).
And it is connected to a hot water line, with absolutely no danger of bursting water lines, leaks, overflows, etc. etc. The air conditioning engineers couldn't figure out how to do it, so it toook an Electronics engineer (me) to figure it out. I just wish that I could patent my design, the whole set-up was inexpensive to build from off the shelf parts. There was some electrical and mechanical work, but it was all pretty easy, once I got the prototype working.
Thankls anyway for the advice, but I have it all working now and am going into my second season with it, and so far no failures.