Whole house humidifier ?

[vwboomer]

I have an Aprilaire 550 attached to the main furnace plenum. My 2 8" ducts from the wood furnace enter about even with the humidifier but point up due to the 90deg elbows inside the main plenum.

Would the cool air blowing past the hum be enough to evap some air when the main furnace fan is on? And how do I swap the wires around on the board in the furnace?

Currently it was connected to the HUM terminal (which would get power after the prepurge cycle) and the 24v COM terminal. I manually turn the main furnace fan on at the thermostat upstairs - do I swap the wire from the COM terminal to the GREEN terminal and keep the HUM wire where it is?

I'm reaaaaally sick of 22% humidity and keeping a pot simmering on the gas stove doesn't seem very economical. This static drives the cat nuts!

 

[mga]

what brand and type of furnace do you have?

ie: lennox...trane..80% 90%?

 

[mtfallsmikey]

Seems like it would be smart to run the humidifier with a separate humidistat/sail switch...or do I understand how your setup was done/wired??

 

[vwboomer]

The main furnace is Carrier - about 94% eff I think. About 12 years old.

The humidity control is manual with a dial on the cold air return in the basement.

When the wood furnace is going, I usually have the main furnace blower switched on by hand.

I do have a transformer and thought about running a switch on that, but it would be more simple to just have it come on when the main blower was on.

 

[mga]

is there a 24 volt pin on the board that gets "hot" when the blower turns on?

 

[vwboomer]

is there a 24 volt pin on the board that gets "hot" when the blower turns on?

I imagine so - however my multimeter was showing nothing across any of the terminals.
Green is the Fan wire. So I believe the green and red on the thermostat should show a current when the fan is switched to 'on'.
I'll check more tomorrow with the meter, but I certainly wasn't hookin anything up just to try it

 

[mtfallsmikey]

I imagine so - however my multimeter was showing nothing across any of the terminals.
Green is the Fan wire. So I believe the green and red on the thermostat should show a current when the fan is switched to 'on'.
I'll check more tomorrow with the meter, but I certainly wasn't hookin anything up just to try it

Good attitude to have...be careful whilst messing around with those control boards, they are big $$ to replace. Try running your fan with the fan switch in the "on" position, see if the humidifier runs...then you will have a place to start.