Controlling Cooling Through Humidity???

[big dave nek]

Found a supermarket today that the only way that the Y1 and Y2 came on was through a Johnson Control Remote Temp/Humidity Sensor. The Heating is controlled trough typical Tempature but the Cooling is controlled through a Humidistat. Right now it is factory set at 65% for cooling. Any idea's or comments are welcome.

[no8no3]

I've seen this set-up many times. Most supermarkets have so much cooling in the form of open display cases, little comfort cooling is required. However dehumidification is almost always needed, as is the case here in the south.

Most of the time a humidistat is paralleled off the thermostat, and around here set at 50 to 60%.

[outside rep]

Was this on a Season 4 unit or a Munters unit ?

[freonrick]

the idea is to keep defrost time down on the refrigeration cases. as already posted most of the cooling comes from open cases.

[big dave nek]

There are four seperate controlers on 10 ton ICP Package Rooftops.

[kano]

That is correct the only way to dehumidify is to bring on full cool. Thus when the humidistat is set at 50% and on a humid day the store gets up to 80% humidity the humidistat will bring on full cooling to remove humidity back to 50%. That is probably the way every unit is set up in that store.

[Milk man]

I would have thought staging the compressors on would dehumidify better. (Not arguing) My reasoning is longer run times. If one oversizes an AC in a house it will be cold and clammy. How is it different in Markets?

[newoldtech]

Originally posted by Milk man
I would have thought staging the compressors on would dehumidify better. (Not arguing) My reasoning is longer run times. If one oversizes an AC in a house it will be cold and clammy. How is it different in Markets?





Houses only have air conitioning, supermarket have many refrigerated cases that help cool the store. Therefore the air conditioning is only needed if it gets too humid in the store.