Recommendations for retro multi-zone refit?

[FuseWerx]

Have a typical HVAC system now -- two stage furnace, 12 seer AC, no zones. There are eight main duct feeds.

I would like to set up a better system for keeping an even temperature in the house without having to rebalance the manual dampers in the ducts every month. I'd like to be sure that 72 degrees is 72 degrees in pretty much every room, and possibly be able to set my own office to be a bit cooler or warmer than the other rooms in the house. My assumption is: Zones.

Is this assumption correct?

I currently have the 2-way X10 thermostat from RCS. Runs pretty much flawlessly in my config. When "night mode" is activated, the temp sets back. Before my wife gets up, it starts to warm up. Usual stuff.

If my assumption is correct, I would have to use more than one thermostat (one for every room/zone I want to balance), right? Can someone give me a step-by-step, written for monkeys shopping list?

[FuseWerx]

So, nobody has any suggestions?

[sic0048]

I'm just researching this myself, so I can't provide step by step instructions. You are correct in thinking that a thermostat is required for each zone. In my research, it seems like most of the zone controllers have some sort of output that you could program for HA. I haven't found anything that works out of the box for full HA, but I've really just started looking.

[smoothtlk]

What about a 1-wire network of temp sensors in each room that is directly affected by each major duct? I assume this is forced air system, and that the balancing would be done via electric duct dampers?

I would keep the current RCS thermostat as the primary, but use the 1 wire sensors to tweek the dampers on given rooms. There would have to be some smarts in the software for balancing, or, manual setpoints so that you could balance the system by viewing room temps (1-wire results) and then remembering each damper position for change of seasons. Doing this all automatically might be a software challenge.

Of course this is assuming that the powered dampers have intermediate position sensing and control and are not binary (open / closed only).

By keeping the RCS as the primary, you don't risk freezing your house if your code is suspect!

That should be much cheaper than running mulitple RCS thermos at $200 per room plus the controller.

Always wanted to play with this myself some day!

[cadillackid]

Multi zone balancing of HVAC is not necessarily the easiest or cheapest task in the world.. I currently run a 3 Zone system for my house, 1 furnace , and AC.. I am using the RCS ZC6R controller which uses RCS WDU's and then I use rectangular dampers.. I reworked the ducts in my basement such that I have 3 trunks coming off of the furnace.., and also ran a bypass damper to keep static pressure from being so high that it ruins ducts or gets noisy.

You could Use 1 wire sensors and an ocelot to control dampers in ducts, but that is only going to offer 1 way solution. meaning that say heat is set at 72 on your RCS stat.. room #1 is 72, Room #2 is 74 and room #3 (where stat is located) drops to 71, so the furnace comes on.. in this situation you would close ducts to room #1 and room #2 and let room #3 have all the air. theoretically this works as both peripheral rooms were above the desired setpoint.

if room #1 drops to 69, room #2 is 70 and room #3(where the stat is located) sits at 72, you will never make the temp in 1 or 2 because the furnace never gets called for as the main stat isnt needing heat.

thats why multizone controllers are such a nice thing, as they have individual thermostats that each one can call for the heating plant to be turned on, and the other zones not calling are shut off from the heat.

the reason for bypass dampers is the fact that your furnace is designed to heat the whole house at once, so it expects to push X number of CFM air through Y square inches surface area of ducting, if you close off runs for zoning then you are still trying to push X number CFM air through say 2/3 less ductwork and you get a lot of whistling, registers rattling, or worse yet popping ducts at the seams. a bypass damper takes air from the supply plenum (heated air) and recirculates it back to the return duct so the blower is in effect still move the same CFM.. after all, ALL air eventually goes back to the blower through returns.. this just sends it quicker..

wasted heat by reciirculating?? Not really.. furnaces are designed to heat air based on a temperature rise.. meaning that say it is designed to give 60 degrees rise in air temp, if you push 70 in at the return you get 130 degree air out. recirculated air is heated and mixes with cold house air.. return air from the house may be 70 and heated air being mixed in might be 120. so the furnace sees average air of say 100 so you would get 160 degree air out.. hotter air will heat quicker thus for one zone callingfor heat the run time is shorter.

I take this even another step in my own system and monitor the air temp leaving the furnace and cycle the gas valve to maintain a certain temperature of air leaving my furnace based on many factors including, how many degrees difference is there between my desired temp and my actual temp (if I cranked a Tstat for morning warm up, give me hotter air than if a stat just dropped a degree or 2), how cold is it outside? (if its -5 out, give me hotter air than if its 45), how many zones are calling for heat? (give me a little warmer air if more than one of my 3 zones needs heat)..

thats kind of how I do my system..

what does it cost?

Ive got about $1400 in my multi zone controls.. that includes my RCS ZC6R controller, 3 EWC zone dampers, 3 RCS wall displays (they look like TX or TR series thermostats, bobcats and 1 wire sensors for monitoring duct temperatures.. plus a secu-16 for my ocelot.

and of course lots of hours of writing ocelot programs,and HS scripts , roasting in the midle of the night because a typo set my heat to 96 instead of 69, freezing in the middle of the night because a bobcat -T registered 121 degrees instead of -1....and oh yeah bunged up fingers cutting sheet metal to install zone dampers.

oh yeah, the RCS zone controller will operate standalone without Home automation if you prefer, it will handle up to 6 zones.. I took mine to a higher level as i wanted to throttle back my furnace based on need for heat or cool etc.

-christopher

[jstaab]

Nice description. I'm planning on having a configuration similiar to yours (over a period of time since I have to units to deal with). One question regarding your setup. I take it that instead of installing a Barometric Relief Damper, you are using a damper that you physically control, thus to also adjust the temperature as you mentioned? I'm assuming then that you have also built in some triggers that opens the damper if the air gets too hot or too cold as well (restricted air flow), thus preventing unit from overheating or freezing.