Where to start with HVAC?

[drvnbysound]

So you have 3 systems, each system is 1 zone, so you have 3 thermostats?

 
Yes. See bolded below:
 

I've been working on a home that's roughly 4,000 sq ft, which has (3) separate air handlers, and (3) separate compressors. Basically 3 individual systems under a single roof. One is for the main portions of the home (living areas, kitchen, dining, breakfast, additional bedrooms), another is for the master suite, and the third is for the guest suite. Each zone/system has it's own thermostat.

 

[pete_c]

Yup; tested those to work fine with the Omnistat2 using 22/2 alarm wire.  Guessing tested with some 30-50 feet of it at the time.  The thermostat to the Omnipro2 cable is CatXX and I left in place the original thermostat wires to the furnace.  I did also add an HAI thermostat isolation module in the furnace for the original Omni RC-80 thermostat and left it in place for the Omnistat2 many years ago relating to some power issues to the Bryant air handler motherboard.  I am impressed that the mother board has a set of diagnostic lights on it with the read codes on the cover.  (well and its now around 12 years old).
 
Omnistat2 Thermostat Isolation Module, 29A00-1

 

Relay isolation for Omnistat2 thermostats. This optional module may be needed for HVAC systems using non-standard voltages. Mounting clips and instructions are included. For use when continuous 24-volt power is not available from the HVAC equipment. It completely isolates an RC-80B series (Rc-8x) thermostat from the heating and cooling system and allows a separate 24-volt AC transformer (sold separately) to power the thermostat. This is necessary because the Omnistat2 receives power from the HVAC unit. If there are separate heat and cool units, this product allows you to only obtain power from one but control both.

 
The above noted; my assumption of use of said remote temperature sensor was primarily for use with the thermostat control.  You can configure to get an average temperature between the thermostat and remote temperature sensors or use one or the other (well more remote temperature sensors).  Neato that it works independently without a connection to the HAI OPII mothership.
 
I did notice when testing the remote temperature sensor adjacent to the thermostat that my thermostat temperature was off by 2 degrees F.  The hole for the wires is sealed from the thermostat.  You can adjust this on the thermostat.  I compared it an old granular analog thermometer.
 
Not sure if the temperature sensor temperature will display on the thermostat concurrent with thermostat temperature sensor.  Never saw that when testing remote Omnistat temperature sensors.
 
Unrelated the Leviton remote combo Temp/humidity or Temp sensors that plug into the Leviton HAI OPII panel display temperatures on the Omnitouch screens.  When I look at the thermostat on the Touchscreen it will only show the Omnistat ambient temperature (which could be local or remotely connected)
 

which can live in my wiring closet. I will need one thermostat in the closet per zone, and at least one remote temperature sensor per zone. The thermostat contains a local temperature sensor, I presume, which can be disabled in place of the remote sensor. Did I get that all correct?

 
Yes.  So you will not see any of the thermostats eh? 

 

[wkearney99]

Yeah, didn't mention, our thermostats have a humidity sensor, as do the remotes (but not the remote controller).  This can be used by a humidifier to deal with overly dry air (which is typically only an issue here in the winter).  I'd imagine there's also some logic in there to take in into account for cooling recovery times and such.

 

[pete_c]

Yeah here got in a major discussion with old friend (HVAC) relating to using the Aprilaire sensors on the air handler versus remote control of the humidity; it became an almost political / religious discussion. 
 
I just look at the humidity levels and typically try to keep them around 35% RH in the winter.  I utilize a dehumidifier in the basement in the summer.
 
Friend was very adamant about using the built in stuff on the Aprilaire (and the sensors outside that plug into the humdifier).
 
He always would say though you want to always think about "heating the house with one candle and cooling it with one ice cube"; metaphorically.

 

[wkearney99]

From what I've learned regarding thermostats there's a lot more to decent ones than just turning something on based on a temperature.  
 
Various simple stuff like not causing compressor freezing or other damage due to improper cycling.  But then it gets more sophisticated when dealing with stages of operation, inside/outside temp & humidity.  All of which often needs to be tailored quite specifically to the equipment in place, at least if you want anything more than basic efficiency & performance.  I'm sure there's an engineer somewhere involved with the Nest that was damned surprised to discover just how complicated it can be...

 

[wkearney99]

n the walls and connect it via cat5 (overkill, I know) back to the thermostat

 
Pay close attention to what a vendor recommends for wire gauge.  CAT5E isn't ideal for carrying current needed for some devices.  Sure, you can "get away with" a lot but you run the risk of running afoul of all sorts of oddball unforeseen complications.  I let the HVAC folks pull whatever they wanted to the device locations, and then I added a CAT5E line.  It's pretty likely I'll be covered, either way, no matter what tech emerges in the future.  But anything that expects 'normal' HVAC wiring schemes will absolutely work since that's already there
 
And while you're planning wires, don't forget about doorbells and video cameras.  I'm kicking myself for not pulling a CAT5 line to where the electrician (stupidly) put the doorbell transformer.  But for the video cameras, I'm covered.

 

[NeverDie]

From what I've learned regarding thermostats there's a lot more to decent ones than just turning something on based on a temperature.  
 
Various simple stuff like not causing compressor freezing or other damage due to improper cycling.  But then it gets more sophisticated when dealing with stages of operation, inside/outside temp & humidity.  All of which often needs to be tailored quite specifically to the equipment in place, at least if you want anything more than basic efficiency & performance.  I'm sure there's an engineer somewhere involved with the Nest that was damned surprised to discover just how complicated it can be...

I'm under the impression that most commonly it is the furnace micro-controller that handles the safeguards (even regarding AC), not the thermostat.  At least that's how the basic Trane that came with my current house works.  That why, at least in my case, replacing one thermostat with another doesn't  require any configuring.
 
On the topic of not having visible thermostats on the wall: there are some thermostats with wireless mobile remotes that you can move around and put on your bedstand or wherever.  The wireless remotes look to be roughly the size of a deck of playing cards.  In that case, I suppose you could maybe put the wireless receiver in a closet or somewhere else that's out of sight, because it uses the temperature at the mobile remote.  Would that achieve what the OP wanted regarding the "ugly thermostat boxes"?  I'm guessing the OP would probably perfer one base receiver and 5 remotes rather than 5 base receivers and 5 remotes.  Is there such a thing commercial off-the-shelf (COTS)?  I'm guessing maybe not, due to wireless range issues.

 

[pete_c]

On the topic of not having visible thermostats on the wall: there are some thermostats with wireless mobile remotes that you can move around and put on your bedstand or wherever.

 
Yup you can get the same thermostat mentioned above with a Zigbee radio and console for it.  
 

 
I have a few beta Utility company testing Openpeak tablets that include a zigbee radio and DECT radio for large utility companies.  These had zigbee energy metering and zigbee thermostat control plus 3G, 802.11X, bluetooth, GB and DECT phone hub connectivity.  These were "test" market boxes.  They are not available today.
 

 

 

 
I have two of these on the nightstands as touch screen consoles running whatever.  Still working on the DECT / Zigbee connectivity.  Everything else works fine.  The original applications were all cloud based linux.  Tiny applications.  Avaya sold these devices to many domestic and international hotels.  They were a bit ahead of their time.  I have mine running Linux, Android and Wintel OS.  Base stuff is EFI and Seabios today.  EFI booting enables multiOS stuff.  Doing this today with another tablet booting into Linux, Windows 7-8, MAC and Android OS. 
 
Geez imagine a cloud based automation hub, DECT phone and internet tabletop tablet that was already available around 2009.

 

[pvrfan]

...As for integrating, honestly, I've yet to see much need for it.  ...
 
A well designed (and scheduled) HVAC system should be largely invisible.  It took us about a month into each seasonal change to arrive at our desired schedules.  But once we got that sorted we've really never needed to control it otherwise.  Save for parties or setting vacation start/stop timestamps.

 
Re integration, the obvious thing that bugs me is that the HVAC system will run or continue to run with the doors/windows open.  In the spring and fall, our house may heat up during the day but, by the time we arrive home, it may be quite comfortable outside.  The security system will 'know' if we open up doors/windows but the HVAC system will happily burn electricity running the A/C at the same time.  I have to override the thermostat to prevent.
 
Or perhaps we're having a BBQ with guests going in an out of kitchen to the backyard all afternoon.  Again, the A/C will blast away unless I override it.  If I've left the patio door open more than 5 minutes, the security system and HVAC should stop trying to air condition the great outdoors!
 
For me, this would be a major improvement in the HVAC's "invisibility".  
 
Craig

 

[pete_c]

Re integration, the obvious thing that bugs me is that the HVAC system will run or continue to run with the doors/windows open.  In the spring and fall, our house may heat up during the day but, by the time we arrive home, it may be quite comfortable outside.  The security system will 'know' if we open up doors/windows but the HVAC system will happily burn electricity running the A/C at the same time.  I have to override the thermostat to prevent.
 
Or perhaps we're having a BBQ with guests going in an out of kitchen to the backyard all afternoon.  Again, the A/C will blast away unless I override it.  If I've left the patio door open more than 5 minutes, the security system and HVAC should stop trying to air condition the great outdoors!

 
You can automate this easily with the Leviton HAI OPII panel automation integration to do whatever you want with your Omnistat thermostat(s).  Personally its fun to watch energy usage.
 
I still have my Omnistat connected via a serial link.  I am already playing with Zigbee automation (Almond +) and have been wanting to purchase the Zigbee stuff for the OPII panel.  That said there are a few users on this forum using Leviton HAI Zigbee thermostats today.

 

[NeverDie]

Maybe this?
 
https://www.forwardthinking.honeywell.com/products/wireless/portable_comfort_control/pcc_feature.html
 
At least it's available.  It says "Adjust the temperature in any zone from anywhere in the home when used with the Wireless Zoning System"  Not immediately clear whether it assumes ugly wall thermostats, or whether all the thermostats can be these wireless mobile units.

 

[wkearney99]

Maybe this?
 
https://www.forwardthinking.honeywell.com/products/wireless/portable_comfort_control/pcc_feature.html
 
At least it's available.  It says "Adjust the temperature in any zone from anywhere in the home when used with the Wireless Zoning System"  Not immediately clear whether it assumes ugly wall thermostats, or whether everything can be a mobile thermostat control.

 
Yep, I've got one with our Honeywell setup.  I posted about it.
 
The downside to this particular setup is the ethernet bridge does not have a published local API for controlling it.  It depends on their free website to handle programming.  The upside is the IOS and Android apps work quite well from anywhere you've got an Internet connection.  I'm not entirely thrilled with this, but at least it's free and DOES NOT require an active connection for any of the thermostat's built-in functions to operate.  
 
And while the Vision Pro line is sold as 'installer only' the add-ons can be picked up quite reasonably from folks like Pex Supply.  I added the Redlink gateway, the remote, an outside temp sensor and and two indoor temp/humidity sensors.  It was pretty simple to add them using the menus on the thermostats (the date code on the back is the setup code).

 

[NeverDie]

Yep, I've got one with our Honeywell setup.  I posted about it.
 
The downside to this particular setup is the ethernet bridge does not have a published local API for controlling it.  It depends on their free website to handle programming.  The upside is the IOS and Android apps work quite well from anywhere you've got an Internet connection.  I'm not entirely thrilled with this, but at least it's free and DOES NOT require an active connection for any of the thermostat's built-in functions to operate.  
 
And while the Vision Pro line is sold as 'installer only' the add-ons can be picked up quite reasonably from folks like Pex Supply.  I added the Redlink gateway, the remote, an outside temp sensor and and two indoor temp/humidity sensors.  It was pretty simple to add them using the menus on the thermostats (the date code on the back is the setup code).

Ashes on my head for not catching that.  Sorry for my redundant post.
 
I'm still not clear though: does it require any ugly wall thermostats, or can it all be sensed and managed using just the handheld thing-a-ma-jigs?

 

[wkearney99]

You could, conceivably, put the wired units in a closet and then add the wireless sensors where ever would provide BEST detection.
 
Note, I'm emphasizing BEST position, not just someplace aesthetically pleasing.  Nor someplace a homeowner guesses might work.  Sensors benefit from being positioned somewhere factoring in the system, the structure, environmental conditions, and how it's going to be used.  I'm reiterating this point to help folks avoid naive mistakes.
 
I don't know how many of the remotes it supports.  I just have the one.  I don't really use it all that often.  About the only times I do are for parties and if someone's here outside of regularly scheduled periods.  Yes, a smart gizmo like a Nest might avoid both of those (but not with geothermal, etc).  Presumably if I know ahead of time I could just as easily use a vacation mode schedule for parties.
 
I've got a pair of these indoor temp/humidty sensors:
https://www.forwardthinking.honeywell.com/products/wireless/wireless_products.html#indoor_sensor
https://customer.honeywell.com/en-US/pages/product.aspx?cat=HonECC%20Catalog&pid=C7189R1004/U
 
They're pretty unobtrusive at around 2" wide by 3" tall.
 
I moved them around a few times to find where would end up being the best place given our floorplans and use patterns.  Trying to avoid sunlight and flow from ducts is trickier than you might expect.  Now, did my HVAC guy get something wrong?  Perhaps, but given this is a custom home it's not like they had much to go on.  That and sun patterns, amount of windows and removal of some trees added a lot of unexpected heat in the summertime.  
 
They're battery operated and listed as lasting a year.  If I wanted to avoid the batteries I could add wired sensors, assuming I pulled the necessary wires for them.  Like this one:
 
http://www.supplyhouse.com/Honeywell-C7189U1005-Remote-Indoor-Sensor-5764000-p

 

[NeverDie]

[Note:  I moved the beginning of this post to here:  http://cocoontech.com/forums/topic/27042-multi-zoning-driven-by-true-variable-speed-air-conditioning-is-it-finally-here/]
 
Anyhow, it's of direct relevance to the thermostat question, because you might very well want to have a lot more of them.  In my own case, I took my own advice from earlier in this thread and already have the thermostat wires in-place behind the drywall for everywhere on the first floor, and adding them on the second floor when the time arrives will be cake because of easy attic access from above.  When I installed the first floor thermostat wires as future proofing in 2009, there weren't nicely integrated systems like there now might be.  Back then my "Plan A" was to use z-wave thermostats to integrate thermostat control with the rest of home automation, and I imagine that's still a live option that's worth comparing.