HAI Centralized controller

[Oman]

Does anyone know if there is a central controller available for the HAI stats? What I mean is that I have a multi-zone house with normal stats wired. They only have 4 wires run to each stat and I can't add additional wiring. To use the HAI stats I have to use all 4 wires for direct HVAC control leaving nothing available for comm wiring.

I have seen at least 2 stats that have central HVAC controllers (Honeywell PC9800 and AprilAire 6504) that use the 4 wires to connect to the central controller and then the controller connects to the HVAC wiring. As far as I can tell these do NOT have any type of PC communication options though. The nice thing about the Honeywell is that it controls the air exchanger and furnace humidifier as parts of a coordinated system to control humidity. This is critical here in Minnesota where we can see 50 degree average temperature swings from week to week.

All the wiring diagrams for the Omni (and the ELK) show the stat wired to the HVAC and then also to the controller, using more wires than I have.

I was thinking at least with the ELK that I might be also to use the relay board with a bunch of rules to control the HVAC but a single bug in my logic could cause the house to freeze which I would not be happy about.

Any thoughts?

Thanks
Jon

[bwally]

doesn't the Honeywell TZ-4 (might be TRZ-4 ?? ) do this ?

[4Shelby]

Yes - the Honeywell TAZ-4 is supposed to do this.