Whatever happened to zone-synchronization?

fentonc

I've been researching thermostats to try to improve a comfort situation with my 3-zone hydronic system (currently intending to add a 'smartish' thermostat so that I can add a wireless sensor to relocate the thermostat measurement point), and I saw several mentions of Tekmar and Honeywell controls that could delay thermostat calls to try to synchronize zone calls for heat, but everything that supports it seems to be a decade old or out of production. My boiler is way oversized (~4x) and short cycles like crazy, so the idea behind zone synchronization is really appealing, but spending maybe ~$800 to install a bunch of 10 year old tekmar equipment (313+552+087+2x532) is less appealing. Do any more recent thermostats support something similar? Or is a tekmar TN2 solution still considered 'current'?

mattmia2

Why not spend the money on a buffer tank?

fentonc

I really like the idea of a buffer tank, as I think it would significantly improve performance, but 1) I'm personally comfortable doing wiring, but not doing piping, so that means paying a lot to have someone else do it, and 2) there's no room to put it in my mechanical room without either adding a lot of pipe to locate it far from the boiler, or moving/replacing the existing water heater. I think a 'reverse-indirect' system might be an okay solution, but that also seems like it might be a 'weird' setup, which means hard to find someone to install/support it.

Spending an afternoon fiddling with some low-voltage wiring seems more fun/appealing, even if it's not a great solution to the problem.

hot_rod

I don’t think you’ll wire and control you way out of a boiler that oversized 

Those complicated PWM, and complicated logic control platform overwhelmed both installer stand homeowners.  I don’t think they were ever big sellers 

The buffer makes the most sense, honestly.

fentonc

“It doesn’t work that well and it’s unnecessarily complicated” is a pretty good explanation. I went with a visionpro 8000 with a remote wireless Redlink sensor.

EdTheHeaterMan

Whatever happened to zone-synchronization?

It left with these synchronized girls
https://www.youtube.com/watch?v=PHbsTIu-XgM

They will be back in 2024.

Zone synchronization, not so much.

HVACNUT

I drew this up a few years ago just diddling around. It's a time delay with a domestic override. Not sure what type of controls you have. 
And the buffer tank is the best bet. And with this diagram, there's no condensate protection without P/S piping. 
I would also use a 40 va transformer. 

fentonc

There's no DHW zone on mine, so using a delay-on-make timer as a simple 'zone synchronizer' is an interesting idea and hard to beat for its simplicity. This is quickly getting into 'just use a microcontroller' territory, but you could come much closer to the Tekmar scheme by using one of those 24-hour mechanical timers with 15 minute intervals - have it turn on either once an hour or twice an hour and use that to drive something like a Littelfuse HRDS 'single-shot timer' (creates a configurable-length pulse every time the timer makes, doesn't reset until the timer opens). This would create a short pulse every 60 or 30 minutes. Then wire some relays so that if any zones are calling for heat it won't go to the boiler until the timer pulses, but once triggered it will get held until the last zone stops calling. This would limit you to 1 or 2 cycles per hour from the whole system, but would force the zones to synchronize their calls.

The tekmar system is even fancier, since it uses communicating thermostats so that it can have zones start calling for heat earlier than they otherwise would if they're below their setpoint but haven't reached the swing threshold yet. All of this is probably fairly pointless on my 3-zone system, but I can imagine that sort of things having a more significant effect on a system with lots of zones with baseboard. I agree that a buffer tank is a much better solution to this problem if you have room for it though.

HVACNUT

At a Tekmar seminar about 15 years ago they presented a zone panel with zone synchronization. At the time, my TV in my  living room threw off so much heat it added a few degrees and kept the nearby thermostat satisfied. Even though it was easily 3° cooler in the seating area. So I asked the instructor if there was a max wait period before it would time out and energize the calling zones. The answer was no, and I knew then I didn't want one. I don't know if they made a revision. I've never seen one in the field. 

Derheatmeister

Why not remove some of the orifices and plug them ?

fentonc

@Derheatmeister - I was under the impression (from reading on this forum) that doing that would likely reduce the efficiency of the boiler, not improve it, but I do not have any strong sources to back that up. I'm open to evidence in favor of it (the installer of the boiler offered that as a suggestion when I was chatting with him when he came to service the boiler this year).