Humidifier install on existing furnace

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I have an older furnace that i wired up to an ecobee4 thermostat.
I bought an aprilaire 500m
I'm not sure what is the best placement of the humidifier.
Supply stack is out of question too cramped.
I could cover over an old basement return which I believe is supposed to be a dehumidifier of sorts for basement in the summer.




Or it could go on the back and leave the old basement return open?
I think I can run a single wire from ecobee acc+ terminal to water solenoid on humidifier
Without needing to use the transformer or manual humidistat it came with
 
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Ours is mounted on the supply side, but from what I understand the preferred side is the return. That way there is no chance a leak would go into the furnace. And it would be exhausting into negative pressure, vs. trying to blow into positive pressure on the supply side.

I just hooked an Ecobee4 up to ours. I used the two wire ACC + and - connections. The one wire method also works, but it will need to be internally powered.
 
I've installed many humidifiers .You do "not" want it on the return. The moisture from the humidifier going across the heat exchanger of the furnace will cause it to prematurely rust through.
 
Mine is mounted so it draws air from the warm side, across the humidifier, and feeds it to the return. It takes advantage of the pressure differential to enhance flow. This is the way I found it installed 32 years ago.
 
Is the air immediately behind the humidifier panel more humid than the air 5ft away from it?

Humidifiers nowadays are evaporators they don't disperse droplets unless you go the steam route.

I have used the cool mist room humidifiers that blow air over a panel and if you put your hand in front of them they don't condense moisture on your hand.

I have seen old humidifiers mounted on horizontal ducts with a spinning rotor inside that caused some rust.

I'm planning on running a wire from the C furnace panel to the humidifier then the acc+ from ecobee

Did you jump C and acc - behind the thermostat or do you have a powered fan humidifier?



Does this look too close on the supply side, about 3.5 inches from exhaust duct
 
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whats wrong with a free standing cool mist humidifier?

I use one for the mild texas winter and it does a good job.

Mine has no filter and works fine with standard water. I fill it with a couple gallons of bath tub water every night the furnace runs.
 
Originally Posted By: Brybo86
Is the air immediately behind the humidifier panel more humid than the air 5ft away from it?

I'm planning on running a wire from the C furnace panel to the humidifier then the acc+ from ecobee

Did you jump C and acc - behind the thermostat or do you have a powered fan humidifier?


I'm guessing your Ecobee question might be directed at me? I have an Aprilaire 760, so it's a powered fan model. It's plugged into an outlet in the furnace room. I don't remember the details exactly, I just followed the included directions for a two wire install. We had an existing humidistat mounted near the thermostat already, so I just moved the wires over to the Ecobee.

The internet is full of debate over supply vs. return side. Sorta like Pennzoil vs Valvoline. I'm no pro, so won't jump in the argument. I'm pretty sure my humidifier would be more efficient on the return side - just because of the negative pressure differential, vs fighting the positive pressure on the supply side. And I don't think the air going into the heat exchanger would be moist enough to make any difference. It's a small amount of air blown through a pad, which is then mixed with a lot of incoming dry air. Just my 2 cents based on internet reading.

I'm excited to try to humidity programming on the Ecobee that varies humidity based on outside temp. That's something I've forgotten to do before when the temp dropped, and had the iced up windows to prove it. But overall, I really like the whole house humidifier. Hope you do too!
 
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