Humidifiers and soft water - Contractor Talk - Professional Construction and Remodeling Forum

kane co plumber · 09-13-2009, 10:58 AM

I am going to be installing an Aprilaire 700 powered humidifier in my personal home and a friend told me I should install it on the supply side of my power vent furnace with hot water. I then talked to a hvac guy on a job site and he said with soft water he would recomend installing it on the return with cold? What are the pros and cons of either.

beenthere · 09-13-2009, 12:40 PM

On the supply side of the furnace. The hot air helps to evaporate the water.
Also, connecting it to the hot water line also helps to evaporate the water quicker. Plus, it can be set up to humidify with out the thermostat calling for heat, if youo hook it to the hot water line.

On the return side. You must connect it to the hot water if you want it to humidify correctly.

You must have either a very large house, or a very drafty house to need a 700.

kane co plumber · 09-13-2009, 01:46 PM

House 4k sf, so r u saying soft water doesnt matter only temp of water.

beenthere · 09-13-2009, 02:57 PM

Yep. Softwater only means you shouldn't have much scale build up on the pad.
Means nothing as far as where to mount the humidifier.

gene2 · 09-13-2009, 06:19 PM

Definately do not hook up to softened water, the salts will collect very, very fast. We have found that connected to the HW side of the WH gives the "cleanest" water for humidifying. Also if it can be done, on the supply side of the ductwork. The more heat, the better performance.

By the way, we hate humidifiers because of the trouble with the water in our area, the clients expectations of "trouble-free" service. I know it is an educate the customer & a profit center, but has caused more grief than any other part of the system. The worst is water leakage when things go awry.

We have found the Aprilaire 700 the best unit for fossil fuel systems, The new Honeywell Steam Humidifier for Heat Pumps due to the lower supply air temp.

beenthere · 09-13-2009, 06:24 PM

Gene.

Check into the Aprilaire 400. Its not my favorite. But, may be the unit for your area. It does require the pad to be changed beginning and middle of the heating season.

Its not a flow through. So water problems are minimized.