multi-thermostate in one zone

[naifmbo]

hi;
Is it practically accepted to use multiThermostate in the same zone has multi-units.

thanks.

 

[walkes]

Multiple thermostats can cause problems in the same zone, depending on their proximity, they may tend to fight each other. One thermostat may be affected by the device controlled by a separate thermostat.

You could have one thermostat control multiple units where possible.

 

[darkvibe]

If you have a DDC system you can use multiple thermostats and control all the units based on the worst case/average temperature in the zone.

 

[blutfort]

What you need to watch out for is contention or fighting between thermostats. In a large zone with multiple units I have seen one unit heating and one unit cooling. Obviously this is not the most energy efficient way of conditioning the space.

If you are fortunate enough to have a DDC system with some horsepower, you could write a quick and dirty routine to prevent a new mode from being entered unless all units were in vent only mode.

Lacking a DDC system if your units use sensors instead of contact closure stats, you could wire the stats in a series parallel configuration. This would have all units see the average temperature of the space.

If you have thermostats you could use relays to prevent zone contention.

 

[NNACons]

If you have zoned your buildings A/C correctly so that the multiple units are all serving a similiar zone ie all units provide heating and cooling to west perimeter zone, and taken that the different areas within this zone have similiar internal loads and usage, similiar outside air proportions and occupant / lighting and equipment densities. Multiple thermostats in the same zone will not cause a problem as all units provide for common or same building load profiles.