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06Honda 07-12-2011 04:49 AM

Dehumidistat Operation

I have a Dehumidistat with a winter and summer side. See pic for unit. This is my first experience using one of these so I am trying to understand how to correctly use it. Any info would be helpful, no manual came with it. It works with a Venmar HRV. No luck at the Venmar site trying to find any info.

oldognewtrick 07-12-2011 04:59 AM

Link doesn't work. You can add a pic to your post by uploading from your computer. Scroll down on the message screen to "Manage Attachments"

06Honda 07-12-2011 06:48 AM

Link reposted, I use an IPAD so the upload box is greyed out.

Mallot999 07-21-2011 06:35 PM

Is that the only stat. mounted on the wall? Usually these are wired in series with the Thermostat. These were popular in Florida (where I used to work as an HVAC tech.) with people who owned vacation and winter properties. It allows the A/C unit to run only when the indoor space reaches a certain humidity level, thus saving money.

Mallot999 07-21-2011 06:44 PM

The way they usually work: You have numbers ranging from high to low. These indicate the % of humidity you are trying to maintain. 90 would bring on A/C at 90% humidity and 20 for 20% humidity. You can set it for max (90% or above) if you want to control cooling by temperature as opposed humidity level. We would tell people to leave it on 65-70% when they were gone for the year with the Thermostat set for 80 degrees, and "off" when they are there (the ones we sold had an "off" setting). Hope that helped!

Eventually, you may want to replace that with a programmable thermostat. Humidistats become less acurate with age!

06Honda 07-22-2011 04:59 AM

We don't have AC. My understanding is the dehumidistat is linked to the HRV. Our house is a one level bungalow has infloor radiant heat so the other dial type thsrmostats are used for that. Thanks for the info, it made me understand better this simple but effective setup. Temp hit 45 C yesterday, managed to keep the house at 28C. Fans on are a must.

nealtw 07-22-2011 10:45 AM

A few years ago I set up a bathroom fan on one of these switches, the idea was that it would look after the fan when the humidy went up in the house. The problem is the relitive humidity outside changes all the time. What we did was in the morning turn the dial until it started the fan and backed it off just till the fan stopped. Now it is set at the relitive humidity and when the shower or laundry drives up the humidy in the house the fan will run automaticly. In the heat you have, I would think you will want everything running.

06Honda 07-23-2011 04:39 AM

Good info, thankyou for that.

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