AprilAire - Humidity Control Remote Mounting

AndrewF · 02-17-2009, 05:24 PM

My Aprilaire 600A came today and I am going to install it tonight.

I really had hoped to be able to mount the control panel on the wall near my thermostat so that I dont have to go to the basement to make any adjustments and to see if it needs to be serviced.

The wall behind my thermostat is a return cavity from an upstairs room.

Can I install the controller on this wall, making a hole into the cavity so it can read the humidity level? Or should I go ahead and mount it on the return trunk in the basement.

My main thermostat has a humidity control function as well, perhaps i just dont even use the AprilAire one and rely on the function built into my Venstar T1900 t-stat.

http://www.venstar.com/Thermostats/SlimlinePlatinumR/

Detail: The Automatic Humidifier Control has a RH sensor on the back of the unit that juts out.

http://www.aprilaire.com/index.php?z...aticHumidifier

**beenthere** · 02-17-2009, 06:07 PM

Use your stat.

hvaclover · 02-17-2009, 07:32 PM

Duhh....

AndrewF · 02-18-2009, 10:10 AM

Quote:

Originally Posted by hvaclover

Duhh....

That wasn't a very nice response.

The disadvantage to using my stat is that it cant vary the humidity level based on the outdoor temperature. It only knows what the humidity set point is and how to get there.

I guess I could wire the AprilAire unit up on the return box and then set the tstat to energize it when it calls for humidity and let the aprilaire unit fine tune the humidity levels with its outdoor temp probe and all. That way I wont have to worry about condensation on the windows on extremely cold days.

hvaclover · 02-18-2009, 01:04 PM

C'mon Andy! It was just a little friendly ribbing between regulars

**beenthere** · 02-18-2009, 02:28 PM

How about a nice Honeywell IAQ thermostat.

Didn't know your stat lacked that feature.

AndrewF · 02-18-2009, 05:11 PM

Well, if you are including me in the "Regulars" club, I am honored

Quote:

Originally Posted by hvaclover

C'mon Andy! It was just a little friendly ribbing between regulars

Winchester · 02-18-2009, 08:23 PM

I installed a 600A earlier this winter. I too thought that the controller could be more remotely placed. But with the probe in back of the controller, would suggest following the guidelines of the manual.

To put this on the wall near your thermostat would probably consider a "larger" hole than just that of the probe for sense of accuracy. Otherwise is more of a recessed whole vs. jutting into the air flow. Not to mention then having to seal behind the hole that you've created to maintain a sealed return.

Myself, I haven't been able to dial in my 600A yet. Most of the time I'm still getting zapped by static electricity but I move it up a bit and start to get condensation on the windows.

Best of luck.

AndrewF · 02-19-2009, 01:14 AM

I got the Aprilaire 600a installed tonight. I went ahead and put the controller on the return trunk. I didnt have time to install the outdoor probe, so I set the unit for manual mode in the MAX setting.

I wired it to come on whenever the HP is running.

I did some testing and found out that if I rely solely on my Venstar T1900 and it calls for humidity, it opens the valve on the Aprilaire, even if the HVAC isnt running. I can set the Venstar thermostat to turn the fan on if there is a call for humidity, but I dont want to do that as I fear the blower will run most of the time to try to get the humidity up.

So instead, I am going to wire a relay in so that even if the Venstar calls for humidity, a relay wont open the valve unless the HVAC is running. This gives me the best of both worlds as my thermostat will control the call for humidity and the Aprilaire Controller will fine tune the humidity levels based on the outdoor temperature using its probe.

Fortunately for me, it will be easier to dial it all in with all the monitoring I have setup.

http://enviro.onlinedesk.net (Charts are at the link at the bottom of the page.)

Thanks all for your input.

**beenthere** · 02-19-2009, 05:56 AM

What is going to control the relay.

AndrewF · 02-19-2009, 11:07 PM

When the Y1 is energized from the tstat.

So, Y1(+) and Common(-) will be hooked to the 24vac coil on the relay.

On the Relay output terminals. The H1 (humidity) terminal from the tstat will hook to the NO terminal, and the H terminal from the humidifier will connect to the C terminal.

So when the HVAC unit is off the NO and C terminals will be open, resulting in the Humidifier being off.

When the HVCA unit is on, the NO and C terminals will be connected, enabling the humidifier to turn on IF the thermostat has energized the H1 terminal.

**beenthere** · 02-20-2009, 07:08 AM

So no humidifier operation if you have to switch to emergency heat.

I'd use a sail switch in the return.

That way. If you have the humidifier connected to the hot water, and the stat can run the fan during humidity calls. It can add moisture weather or not you have a heat call.

AndrewF · 02-20-2009, 11:35 AM

Quote:

Originally Posted by beenthere

So no humidifier operation if you have to switch to emergency heat.

I'd use a sail switch in the return.

That way. If you have the humidifier connected to the hot water, and the stat can run the fan during humidity calls. It can add moisture weather or not you have a heat call.

Good point.

I could just hook it to the G(fan) wire and just tell my tstat to energize the fan when it calls for eat, regardless of whether it is HP or Aux. (Right now the AirHandler energizes the fan when there is a call for heat.

I hadnt thought about a sail switch.