Whole house humidifier, working correctly???

Discussion in 'HVAC Heating & Cooling' started by Master Brian, Dec 30, 2008.

  1. Master Brian

    Master Brian DIY Senior Member

    Nov 13, 2008
    I have a whole house humidifier, unsure of exact brand, but it the same as either an Aprilaire 224 or 440.

    My question is the water seems to continuosly run through the system even when the furnace isn't on. Is this normal? I normally leave the fan set to ON, because I like the airflow and I don't seem to get cold pockets throughout the house.

    I recently, within a month or two, replaced the valve, because the old one was sticking.

    I'm not sure where the humidity is set to, but I can check when I get home if that matters. It doesn't seem to be overtly humid in the house and I know it is set a little below normal, because the dryer air was giving my 3y/o nosebleeds.
  2. Cookie

    Cookie .

    Oct 7, 2005
    I don't think the water should be running continously, nope.
    My son, age 23, still gets nose bleeds if it is too dry in the house. He had one just the other day.
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  4. Chris75

    Chris75 Electrician

    Aug 12, 2007
    Litchfield, CT
    They should only run with a call for heat. few exceptions though.
  5. SteveW

    SteveW DIY Senior Member

    Feb 11, 2005
    Omaha, NE
    What happens when the furnace and fan are both off?

    If it still runs, the solenoid is stuck open.

    Also, try to get the name and model number.
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    If installed correctly, it should only run if the fan is on (doesn't require heat to be called for), AND the humidity is lower than the set point.

    Some models of AprilAire use a flow-through wick, some use a drum, reservoir. The flow-through wick always runs water when it is on, the water that doesn't evaporate, runs down the drain. The units that use a rotating drum (or other reservoir), only run water when the float drops and needs to refill the tank.

    The type that uses flow-through is similar to an evaporative cooler without the tank and pump. You're less likely to get stagnent water with this type, since it could end up drying out in between. A tank type drum could sit there all summer with water and grow some nasties.
  7. Master Brian

    Master Brian DIY Senior Member

    Nov 13, 2008
    I forgot to get the model # last night, I'll try to post it later.

    It is the type that has about a 2"thick x 10"wide(approx) x 8"tall(approx) filter. The water flows through the filter and drains directly out. There is no storage or drum, so I guess it is the flow through wick type.

    Like I said the fan is set to ON, not AUTO, so I guess this is normal. The air quality feels pretty nice, not to muggy/humid and not too dry. I also don't think my daughter has had a nose bleed for a month or two, so maybe I shouldn't mess with anything, but I feel like water is being wasted.

    Is it bad to play with the saddle tap, to slow the water down, just enough so that not as much is being wasted? ....or will that just mess things up. I hate to play with the humidity level, since like I said that seems good.

    I would also like to ask about the humidity controller, is there anything wrong with mounting that in the basement near the furnace? Or is it better left in the hallway next to the thermostat? My last house had it mounted on the furnace, but I believe the inspector, when house was sold, said that wasn't correct. It was there when I bought that house. I wouldn't mind it being in the hall if I could get a better looking unit or a thermostat with a humidity control. I just need some pointers on what to get there.

    Thanks again.
  8. CarlH

    CarlH New Member

    Feb 4, 2007
    Northern VA
    My furnace has a separate power tap for the humidifier. It only allows power to the humidifier when there is a call for heat and the fan is running. Turning on just the fan on mine does not allow power to the humidifier. It could be that the humidifier is not connected correctly, or this could be the best solution for a furnace that does not have a separate tap for a humidifier.

    If the humidity controller is mounted to the furnace in a way that it is in the path of the incoming air, then it is in the correct spot. This would mean that the controller is mounted to the inlet duct so that the part that detects humidity is inside the duct. It should be mounted upwind of where the humidified air is introduced so that it can sample the air before the humidity is added. The problem with this location is that it is less conspicuous and often forgotten about. Not that you should need to make frequent changes to the humidity setting.
  9. PEW

    PEW DIY Senior Member

    Sep 2, 2004
    I use the same unit you are describing.

    Both the internal fan and water should only run when the heater fan is on, and the humidistat is calling for humidity.

    Do not try to cut back on the water supply (with everything working properly). There is a very small orifice in the unit to limit the water volume. It is replaceable as is the media you described. I usually change mine every few years, but the condition of your water may dictate differently. When the unit is running you should see waste water going down the drain.

    If the humidistat is wall mounted, I would leave it by the thermostat, you want it to read from your living quarters. There are duct mounted units which can be install in the return duct.

    Be careful, do not over humidify the house, that can lead to other problems you do not want.
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