HVAC Frustration. Need Advice

[ano]

I need to replace my AC/Heat unit and have it HAI automation capable.  Sounds easy but it isn't.  I should add, I really need a zoned system as well. 
 
The first comany came out yesturday. They recommended a Trane XL16i with three zones. O.K. All looks good, but then I mention that I really want this to be be controllable by my HAI system.  I have printed out the specs of the OMNI Stat2, and gave it to them, but this is where the problem starts.  From what I understand, the Trane zone controller has this LCD panel there the temps are set, and it doesn't sound like any other thermostat options are possible.  I have two more companies coming for estimates but I'm afraid of this repeating again and again. 
 
Has anyone installed a zoned system and had it controllable with HAI thermostats?  It doesn't look like my system will be controllable and i won't be too happy.  Or maybe any zoned system controlled by HAI? 
 
Any advice is appreciated. 

 

[fcwilt]

I have a system from Lennox. The zone controller uses plain old thermostats so that HAI units would work fine. I have another home with a Water Furnace unit. That zone controller also works with plain old thermostats.

 

[tmbrown97]

It's perfectly doable - you just need to be talking to someone who actually knows what they're talking about.  Many of the standard zone controllers take normal thermostats as Frederick mentioned - in fact, I have a spare 2-zone controller sitting in my office... I really liked the RCS communicating zone controllers, but unfortunately it seems they discontinued those; now your only good option is a normal dumb zone controller connected with communicating thermostats like the HAI.
 
Just make sure they don't put in anything with a proprietary control panel - you want a system that uses industry standard control components.

 

[ano]

I have two more companies coming over to give me quotes.  Although I'm sure what I want is possible, trying to get a system configured like that is a big challenge.  I live in Phoenix so getting the AC to work like it was designed is very important, and with AC bills over $350/month in the summer, all the energy saving features need to work too.  These units have not only two or multiple speed fans, but also multiple speed or multiple compressors.  My fear is I'll be able to control it, but all those extra energy saving features I paid for won't work. 
 
Then there is the problem that the guy coming to your house is a sales guy, not an engineer.  If the option for an industrial-grade zone controller exists, these guys don't seem to know about it.  And even if my thermostats will communicate with the zone controller, the zone controller has to communicate with their fancy HVAC unit, and that can be a problem also. 
 
Thanks for your advice. I'm going to continue to chug away with these other companies to see if I can get something that will work.  

 

[iostream212]

I was looking into this myself for zoning my system and ran into similar problems. The main problem being that the HVAC people usually have their system that they are trained on and will try to push it on you. After I showed the tech my HA system and he saw all my wiring in the attic he looks at me and says "I don't know why you would need us. You could totally do this on your own." That was the first thing we agreed on. Turns out my system was already zoned, but had manual dampers. Basically all I need to do is get a multizone controller, motors for the dampers, and I should be in business. However the tech said I did need a bypass zone because the pressure would be too great if one leg was closed completely. I was quoted $200 for that. W2P was this the RCS controller you were talking about? http://www.smarthome.com/3038C/HVAC-4-Zone-Controller/p.aspx I have RCS so I was looking into this board to get multizone control. But in all honesty this will cost me $600 out the door vs the HVAC company's quoted $2000.

 

[standon]

I have an xl19i with an older Honeywell zone controller working with ecobee thermostats and no issue.  I would check out the specs for the zone controller they are recommending, I'm guessing there is far more than one option for the controller. My zone controller handles the damper, while the wiring to the thermostat looks exactly as it would if the system was all a single zone.  

 

[ano]

Getting details from these guys isn't always easy, because I don't think they know. Again, these are sales guys.  I don't doubt they can get it all working, but I like to see it all spelled out at the start.  Especially for the $10,000+ that is being talked about. I'm sure they know zone controllers and the like are cheap so they can juggle around a bit later and still make money. 

 

[tmbrown97]

iostream - RCS used to make a different communicating zone controller in which the serial connection from the M1 was to the zone controller in the attic, and you had to use their specific Wall Display Units (look like a thermostat but connect via 4-wire bus).  That's what I have here and I love it because I can look at any tstat and see why the system is on - they'll all show "MRT" or MOT" (minimum run times, etc) and let me know where it's running; you just can't get that level of integration with a dumb zone controller and smart thermostats because none of them are familiar with each other.  Sadly, RCS cancelled that.
 
Do you really need 4 zones?  If you only need 2 I have an RCS 2-zone non-communicating (the 2-zone version of that) that is just collecting dust under my desk - you're welcome to it.  You can't zone your system too small or the pressures will be too high so be careful when trying to DIY this - you definitely need to do your research.  I was hoping to go to 3-4 zones but put that on hold until I replace this old system completely.

 

[ano]

O.K. Second guy came and went. He said that Trane zone controllers can't be connected to "regular" thermostats but thinks Carrier one can be. He is going to speak with the engineering dept. at Carrier to see if its possible.  I know HAI can "talk" with some Carrier systems through a serial port, and he will see if that is possible as well.  He said that Honeywell Zone controllers will work, but he was pretty negative on those, saying they don't work well, and that they require air bypass valve.  I know that used to be true of the single stage ones, but I'm not so sure that is still true.  He is going to do more research.
 
Tomorrow will be company three. This is not an easy task to accomplish. 

 

[ano]

Thanks for the offer Work2Play.  I probably will need three zones.  If I was a bit younger, I might consider this as a DIY project, but the more I'm learning, its pretty involved. Doesn't look like a project for the faint-at-heart.  The cost I'm getting for just the zoning is $4500 - $5500 which should give you some idea of what's involved. 
 
Overall the direction that I'm seeing in HVAC systems is a bit disturbing.  As their systems get more complex, they are using this fact to make it HARDER to hook their systems to other systems.  Their systems are becoming more proprietary than ever because they want to force you to buy ALL their equipment and more.  If your Trane, for example, and you make all your communications proprietary, they can force others to have to license systems that connect to it, and they can force consumers to not only buy their system, but buy their high-end systems if you want to communicate with it. If you want to control it remotely,  great, buy our $800 interface and it will work great with OUR iPhone app.   

 

[apostolakisl]

Zoning as system is not that complicated, but it can be a lot of work, mostly because you have to separate the air flow routes.  If you are doing a virgin system, it isn't that hard, but retrofitting may be a challenge depending on your details.  The zone control boards act just like a single thermostat from the perspective of the HVAC unit.  Honeywell makes a good 4 zone board that handles just about any type of system out there.
 
If you want three zones, you need a minimum of three dampers which send air to 3 "sub" plenums, which will branch off to each register.  The zone board is connected to 3 regular thermostats which you locate in the appropriate space of the house and wire back to the honeywell board just like the honewell board were the HVAC unit itself.  When a thermostat calls for AC or Heat, it tells the zone board, which then opens that damper and turns the unit on.  It can even work with cooling and heating at the same time, it just alternates.  Multi-stage compressor and fans are handled by the Honeywell board, but I am not 100% on how they decide what stage.  If you go to honeywell website, I am sure they have downloadable stuff.  I have a honeywell board on my office system with 3 zones on each of 2 units.  But my units are single stage, so I'm not super familiar with the multi-staging.  But I have read the manual a while back, and it does have a lot of options for all kinds of different configurations.  The board costs a few hundred bucks and the dampers aren't that pricey.  So mostly it is a matter of changing up all your ducting . .. that is the hard part.
 
EDIT: The thermostats that run to the zone control board can be any thermostat that uses the standard wiring.  So all of your HAI compatible thermostats should work, assuming they use standard wiring (which I have to believe they do).  The zone control board is not connected to your HAI.

 

[picta]

It looks like RCS ZC zone controllers are still available: http://www.automatedoutlet.com/Home/RCS-Zone-Controllers, and it can use HAI omnistats
I used to have RCS 6 zone controller, it worked great with my multistage heat pump.

 

[Del91574]

Time for hardware to start moving to bacnet.

 

[tmbrown97]

To be clear, there *were* two types of RCS zone controllers - the kind available now uses standard thermostats... The system I installed in this home does not - it's a much smarter system where all the components talk to each other and their proprietary wall display units are required.

 

[picta]

To be clear, there *were* two types of RCS zone controllers - the kind available now uses standard thermostats... The system I installed in this home does not - it's a much smarter system where all the components talk to each other and their proprietary wall display units are required.

 
That was the type of system I had, in a 6 zones version, with proprietary WDUs. It was a very good "smart" controller, I wonder why RCS stopped making them...