Multi-zone HVAC

[Goose66]

Anyone doing reliable multi-zone HVAC with an ISY99i? I have looked at a multi-zone controller with 4 Venstar thermostats (very expensive) or several SimpleHomeNet I/O devices with programs on the ISY99i controlling (not very reliable). Is there something in between these, like a Insteon controllable multi-zone controller board that can work with cheaper, digital thermostats. Something like the X10/RS485 devices that RCS used to make (or still does, perhaps).

[io_guy]

RCS still makes hardware zone controllers. SH has a 4-zone unit for $190. If I used all "true" thermostats that's what I'd use.

 

My system is 2 zones. A thermostat downstairs and a temp sensor upstairs (1-wire). I use an EZIO8SA to control duct valves based on the 1-wire values.

[Illusion]

I am doing highly reliable multi-stage 3-Heat 2-Cool zoning with my ISY.

 

I do not think I am going to be able to help much as I ponied up the $$. Venstar Stats with adapters, Honeywell HZ 432 zone controller (the best there is), and a few I/O links to run a special de-humidify mode and also to disable aux heat based on ISY condition monitoring.

 

I carefully considered other control options, but ultimately decided that going all the way was the best solution. I have seen HZ series of zone control boards going for as little as $55 new on eBay. I would not try to skip this part. A dedicated purpose built zone controller is essential for equipment safety. This includes monitoring of discharge air temperature with de-staging control.

[apostolakisl]

You might look at a CAI webcontrol unit. They are inexpensive, integrate with ISY via io_guy's application, and can be programmed to operate independently with or without ISY (or other) supervision (so if com goes down they still will operate).

 

They can take 8 1-wire temp sensors and have 8 digital inputs, 8 digital outputs (that you would connect to relay boards), and 3 analog inputs. There are 8 addressable variables that ISY could post values to for temp settings. They have an internal PLC programming language that would be perfectly sufficient to operate an hvac unit without any outside intervention if so desired. They are IP enabled and accessable via a gui or REST interface.

 

A single CAI unit might be all you need to operate all three zones assuming you can get wire from the unit to wherever you want the three temp readings taken and that they aren't too far away. CAI unit is $40 with shipping and a relay board will be about $25 on ebay. You will also need a 9v power supply and a cat5 connection to your internet connection (or you could buy a wireless bridge).

 

I have a couple of these units and am enjoying them. They are fairly simple but with creative thinking, you can actually get them to operate in a very sophisticated way. It mostly comes down to getting a grip on the PLC language. It is a very simple language but putting together the simple commands in with some care and logic produces complex operations.

[junkycosmos]

With the minor annoyance of the prior issues with the stat 2441 stat adaptor aside (SH issue with firmware) I have been very happy with our 2 zone setup.

 

I went with a honeywell zone controller board in between the t1900s for some measure of safety after seeing a few horror storries of wireless going wacky. Might be isolated case noted here http://forum.universal-devices.com/viewtopic.php?f=25&t=4727&hilit=fried+ac but prior to zoning I also encountered something similiar of a "bouncing loop" with my own T1900 turning my humidifer on and off

I would also note that the support guy at Venstar was very helpful but in the end we found no good explaination.

 

Current setup with 2 t1900s both with a 2441V works great and the ISY makes programming simple while the zone controller by honeywell has reasonable safety limits and lock outs. Zone board has both overheat and overcool limits. Noted I did go with the higher end zone board with more than needed zones since it has options for multi stage heat that can be locked out by preset outdoor temp. I.E. Leaving windows open at night and the furnace will not kick into 2nd stage heat trying to warm the yard.

 

Hope the links don't offend anyone but I have ordered from this place with success, unit appeared new non gray market.

 

HZ432K

https://www.pexuniverse.com/honeywell-t ... -panel-kit

 

C7089U1006

https://www.pexuniverse.com/c7089u1006- ... oor-sensor

 

J