Humidity control for hydronic house, opinion please

GMcD

Since there is already an air supply and duct system, why not a couple duct mounted electric humidifiers like the Nortec or Dri-Steem units. Set up the controls to cycle the AC units on a call from either temperature or humidity (set up so air supply temperture during humidification is reset to seasonal required temp for heating or cooling).

Cosmo_3

H.O., wants to add a humidifier in his home. 4K sq ft single level home, all wood floors w/ tile bathrooms. Hydronic baseboard throughout except for radiant in bathrooms. 2 separate A/C systems bedroom area air handler in attic, kit/din/liv areas air handler in basement.

I was thinking of installing a humidifier in the basement A/H, and installing a "Fan Handler" control to keep airflow down to prevent unecessary draft. Use the Aprilair #8570 T-stat to control using Outdoor temp.

I would like the Fan Handler to keep blower constant @ 10% to prevent mold and move air into bedroom area.

To tell you the truth I have already advised him to use a free standing humidifier in the bedroom hallway, but he can't because his daughter's wheelchair needs room to pop wheelies in the hall (she is AMAZING on that thing!). I have also seen some stand-alone humidifiers w/ dedicated ducting.

Opinions?

Cosmo Valavanis

Dependable P.H.C. Inc.

Cosmo_3

Do you like teh steam units?

H.O. is concerned about the fact that the basement located A/H does not serve the bedroom area- where he wants the humidity most. I am relectant to install a humidifier in an attic. Will humidity in a closed evironment seek to equalize, or will one half of the house be drastically higher R/H than the other....

Cosmo Valavanis

Dependable P.H.C. Inc.

GMcD

Vapour pressure

Humid air will spread and infiltrate the whole house. The other issue is watch the indoor humidity levels versus envelope leakage and window quality. A small increase in indoor humidity with poor windows and envelope leakage can lead to serious problems in the winter. Check the envelope first.

Cosmo_3

TIGHT

The house has 2X6 walls, I saw the insulators use icynene on the walls, attic is also icynene in cathedral ceiling areas, r-30 cellulose in attic portion. Exterior has Dry-vit, this consists of 1.5 inches of foam glued to the exterior plywood, and the lightweight stucco product applied on top. All Pella 2 pane ARGON filled glass (you know the funny gas that leaks after a couple years...)

Cosmo Valavanis

Dependable P.H.C. Inc.

Ericjeeper

I needed a dehumidifier last year

I had so much humidity in my new home. My airconditioning ducts in the attic were dripping. my humidity was 45 plus percent..
I am hoping the new house has dried out a bit over the summer.If not I plan on running a dehumidifier this winter.. Hopefully my ducts won't sweat.They are insulated but they still dripped.I ended up taping cardboard over the returns, and shutting all the supplies down., I will quit rambling

GMcD

Sounds OK

It sounds like the envelope is pretty good then. Shouldn't be a problem to boost the indoor humidity to the 35% to 40% range in winter with that envelope. Yes, I like the electric steamers- they provide good dependable humidity compared to the recirculating type units that generally use infrared or atomizing units to make water vapour. Just watch the water quality to make sure you don't get mineral build-up.

Cosmo_3

Not what you think

The reason you had all that water was not just the humidity in your home, it was the fact that the warm air from your house was convecting up to your attic installed A/C ductwork, cooling off, and condensing.

Yes, cutting off all the supplies and returns in the winter will help alleviate this problem.

Thanks


Cosmo Valavanis

Dependable P.H.C. Inc.

rb_6

steam

I'm with Geoff..this our Nortec unit...works great.

Joe Brix

SHould you run a humidifier

in an AC duct system with no heat, just using the blower? I wouldn't think the moist air would carry well without heated air. Just wet the inside of the ductwork. Wouldn't it be better to just use a stand alone humifier mounted in a wall or closet like an Aprilaire 350?

GMcD

No heat humidifying

Yes, the moisture is absorbed by the dry air. The trick is in the design of the steam or moisture distributor heads in the duct to avoid visible drops of moisture as carry-over. If the walls of the duct are at the same temperature as the dry air in the duct you are injecting moisture into, how will moisture condense on the duct? This standalone humidifiers are just injecting moisture into the room air at the same ambient temperature, and the moisture only wets cold surfaces like crappy windows and window frames.