DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (
-   HVAC (
-   -   humidistat (

plumcass 04-01-2009 07:15 PM

i have a ranco humidistat just above a honeywell t8400c 1099 2 thermostat. can you tell me which is the proper sequence of operation?
should the humidistat be the primary control?

beenthere 04-01-2009 07:28 PM

Depends what you want to do.

hvaclover 04-01-2009 07:41 PM

The humidistat should be subordinate to the t'stat assuming a regular furnace function.

beenthere 04-01-2009 07:43 PM

Some commercial apps.
I have them as primary. Because they bring on the A/C and a 5KW heater, to keep the humidity down.

plumcass 04-02-2009 10:01 AM


Originally Posted by beenthere (Post 253658)
Depends what you want to do.

the house is residential with central air and heat unit.
i want the house to cool or heat when the humidistat is satisfied.
i am in the process of changing my manual heat cool thermostat to an auto heat cool.
can you explain the proper sequense of operation ?
the house is in florida and will be empty for long periods of time in the summer.

beenthere 04-02-2009 12:47 PM

Will the humidistat only control a dehumidifier, or will it control other devices.
Or will it bring on the A/C to dehumidify.

plumcass 04-02-2009 06:35 PM

in the summer it will control the ac

beenthere 04-02-2009 07:24 PM

You can do it a couple ways.

One way.

Just wire the dehumidistat parrallel with the thermostat.
That wat, either one can bring on the A/C.
But it may over cool on rainy days.
Plus, you can't have the thermostat set to auto change over, or it would damage the A/C.

Next way. Is to add a lockout relay. That if the thermostat calls for heat, it shuts off he A/C.
And brings on the heat. After the heat is back up. if the humidity is still high, the A/C will run again.

May I ask, if you considered getting a thermostat that does cool to dehumidify automatically.

All times are GMT -5. The time now is 01:37 PM.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

Search Engine Friendly URLs by vBSEO 3.6.1