Humidistat turns on A/C?

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Well then, whats a hemostat for?
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Not many in the US, vs our Canadian friend's. That's another mistake.
Another mistake is to imagine that it takes less heat energy to humidify a house than the energy saved by turning the thermostat down 2 F for equal comfort. That only works if you live in an airtight house without much insulation, eg an old oil tank in Barrow, Alaska :-)
Winter humidification typically consumes 10X more energy than it "saves."
Nick (again repeating obvious truths to people who will not listen.)
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Well, to stop the static shocks, bloddy noses and itchy skin, running my humidifier may cost me a total of an extra 50 cents per month. Well worth it if you ask me....
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Personally, I don't give a damn about the added cost or the savings. What I do care about is comfort breathing, dry mouth, shrinking furniture, and static shocks.
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Hello Again to all,
After doing a bit of detective work, here's what additional information that I've gathered:
The cenral air conditioner is a Ducane AC10B30, the thermostat is a White-Rogers thermostat (model 1F80-261), the furnace is a Keeprite high efficiency central forced air furnace (model PS-90), and the humidistat is a Broan knob-type switch which controls the furnace's blower through an air flow pressure switch.
The R, W, G, and Y terminals of the thermostat is connected to the R, W, G, and Y terminals on the control board of the furnace, respectively.
The humidistat pressure switch is connected to the R and G terminals of the control board on the furnace.
And the central A/C is connected to the Y and C terminals of the control board.
As shown below, disregard the periods, they're just used to line up the letters (sorry for the poor diagram): .....................Furnace Thermostat Humidistat-----------R--------- | .....................W--------- | Humidistat-----------G--------- | .....................Y----------+---A/C .....................C--------------A/C
Whenever the humidistat turns on, it is turning on the A/C as well. It seems to be backfeeding the Y terminal through the thermostat (the Y and G terminals of the thermostat seem to be internally jumpered together from my ohmmeter readings). Any more suggestions on this problem?
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Jumping into to this late, but when the thermostat fan switch is set to "Auto" there is a jumper inside the thermostat, that jumps 'G' (which starts the furnace fan) to 'Y' (which starts the outdoor condensing unit).
You will have to add a relay.
snipped-for-privacy@gmail.com wrote:

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wrote:

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Hopefully I am not double posting.
KJ, when you say the 120V control connections, it sounds as if you are talking about the line voltage to run a humidifier.
It sounds to me like 'Winterpeg' is not running a humidifier but trying to reduce high winter humidity by ventilating with cold dry air. Its a Canadian thing, tight homes and high winter humidity.
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Sorry, I thinking Humidifiers...not dehumidifiers...
I'm located where we need to add humidity, not remove it in the winter.
~kjpro~
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Then why exactly is he concerned about the A/C coming on?
He would need it to dehumidify?
~kjpro~
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I think the installers wired it up so on a rise in humidity, it would start his fan. Probably a fresh air intake to the return. Sucking in cold dry air will bring humidity down so you do not get window condensation.
Except with the fan switch in "Auto" position, everytime he puts 24 volts to G, to start fan, he is also starting the condensing unit. Setting the fan switch to 'Auto' is a switch inside the thermostat that 'jumps' Y to G. So the dehumiditat sends 24 volts to G on the furnace but the power goes back to the stat, through the jumper to Y and starts the AC in the winter.
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Yep, I understand the jumper to the condensor, just can't see how just a blower pulling in outside air could make that much of a difference.
Thanks,
~kjpro~
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~KJPRO~ wrote:

10 F outside air will have about 10-20% RH at room temperature...
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Not a humidifier KJ, he is dehumidifying in the winter.
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now this post shows up, Sorry KJ
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Not a humidifier KJ, he is dehumidifying in the winter by ventilating with cold dry air. Tight house too much winter humidity.
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Have the dehumidistat 'take' power from R. On a rise in indoor humidity, it will power a coil of a 24 volt DPDT relay. The return from the relay coil goes to C.
One set of NORMALLY OPEN (NO) contacts will close to send power to G and will start your furnace fan. A set of NORMALLY OPEN (NC) contacts will open to break Y and prevent your outdoor condensing unit from running.
You will need to add an on/off switch between R and the dehumidistat. The switch is turned ON in the winter and OFF in the summer. Otherwise the dehumidistat will prevent the air conditioner from coming on in the summer. You need to remember to flick the switch back on the next winter.
You may have to look and see if there is some motorized damper that opens to let fresh air into your return air duct work. You may need to power that motor the same time you power G.
Sounds like you are in Manitoba. Call Ecco Heating Products and see if they know some one with a brain to come over and wire this up for you.
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Thanks for all your great responses. Abby, you hit the nail on the head, in Manitoba, high humidity becomes an issue in the wintertime due to the "tightness" of the house insulation.
...the relay solution sounds like it will do the job.
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Abby, from you experience, is this how this setup should normally be wired? I would imagine this to be a pretty common configuration in Canadian homes.
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Peg, I grew up about 7 hours drive east of you. To figure out how cold I would be 'tomorrow', I just looked at what Winnipeg was 'today' and added 5 degrees.
HRV is really the way to go, have it cycle on/off with a rise in humidity. Maybe even get a cheap one from Beaver Lumber (is it Ace now? left Canada 7 years ago)
You can try the relay like I said, and maybe you only have to break 'Y'. Instead of a switch you could also set the dehumidistat up to max like 80 in the summer so the damper never opened, and then set it back down in winter. How low you set depends on how good your windows are.
Ecco Heating Products will know of someone who can fix you up, else buy me a Westjet return ticket and I'll do it this summer when I go back home :-)
For the time being, open the breaker to the outside unit so it does not run. After you rectify the problem and at least a day before you ever run the Air conditioning, turn the power back on to the outdoor unit. You need to let the crankcase heaters in the compressor heat back up before you start it. Otherwise I would say to never shut the power off to the outdoor unit.
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