? data logger to track zone pump on/off ?

[000utback]

When we got our new Buderus BG142 with outdoor reset, we also rearranged our heat zones and added heat to about 500 ft2 that previously had none. Now we're running 4 zones (4 stats, 4 pumps) for a variety of space heating styles, and 3 zones (3 stats, 3 valves, 1 pump) of floor radiant. I would like to know how much each zone is running. For example, if 3 zones run 20 minutes/hr, and one zone runs 60 minutes/hr, I could explore adding more emitters to that zone to get more equivalent run times. Run time % would also show how well the outdoor reset heating curve is set up. I can set up a computer to store/display data, for example if the devices were polled each minute to determine state, and that data would be stored, then I could do an Excel graph that would show how much they ran. Way cool. I don't know how to get the data. What widget would attach to the TT for each stat (24V) to show whether it's open/closed? How would that widget connect to the PC, and what software would collate the data? Or poll the pumps at 120V instead of the stats. Even more cool would be tracking the water temps as well. Could you imagine a graph with 7 different horizontal lines to show off/on, overlaid with the supply and return temps? Is this heaven, or what? Even add a boiler status indicator...

 

[Dana]

The smallest BG142 has a min-fire output of ~23-25,000 BTU/hr, which could be a short-cycling problem for any l0w-mass zones. With enough water mass in big old radiators it's not bad, but for a low mass radiant floor it could be, and DEFINITELY a problem for small zones of fin-tube baseboard.

The Energy Detective (TED) can be a datalogging-nerd's dream tool for applications like this if set up tracking AC current on the power to the individual pumps. There may be cheaper, easier to set up versions to track thermostat behavior out there, but I can't point you to one offhand.

 

[Sponsor]

 

[WorthFlorida]

I just replaced a six zone Taco controller wired for six thermostats and by chance it was connected to a Buderus. There is only one pair of wires to turn on the furnace when anyone thermostat calls for heat. One relay contractor closes the circuit.

The only way that I know of is to replace all the thermostats with a smart/WiFi unit. It can get expensive since the Honeywell model is about $190. However, the hour run time comes from a monthly report from Honeywell. It only gives hours, not day or time. I’m not sure if Nest has an immediate on line report. Maybe other smart thermostats might have this desirable feature.

 

[WorthFlorida]

If you're good at wiring and building panels, you can make your own "hour run meter" for each circulator. This is the most basic design with a 100v-120v AC input. It's old school but it will work. Search for "hour run meter".

https://www.ebay.com/itm/AC100-250V...m=200999188696&_trksid=p2047675.c100005.m1851

 

[Dana]

Run time accumulators don't really say when the pumps were running. When fine tuning a reset curve it's more useful if it can be correlated with outdoor temperature data.

There is still a bit concern that this boiler may short-cycle on zone calls at condensing output temps, given the relatively high min-fire output and the number of zones. At least part of setting the curve is to avoid that outcome, which cuts into boiler efficiency & longevity. A bit of analysis is in order.

 

[000utback]

Mine is the GB142/30. Thanks for the first ideas on tracking behaviour. Totalizing is better than nothing, and looks like an economic way to start. Saturday we'll start deer hunting in earnest, and think about this while we're on the deer stand. I'll come back to this later. Didn't want people to think I posted a question and never came back.
Best to you and yours as you head for the woods.

 

[Dana]

The behavior is somewhat predictable when more details about the zone-by-zone radiation types & sizes are known. It's unlikely that all zones have sufficient heat emittance at condensing temperatures to deliver the full min-fire output, which means it'll cycle on/off on zone calls a bit.

But at the same 20% duty cycle there's a huge difference in efficiency and wear & tear on the boiler between one minute burns 12 times per hour vs. a single 12 minute burn once per hour. One is boiler efficiency heaven while the other is short-cycling hell, which is why merely summing the burn times per hour or day or the pump run times (which doesn't tell you anything about what the burner is doing while that pump is running) isn't even close to being good enough. To the extent possible, do the math on the radiation.

Good luck on your hunt!

Are you hunting with pickup truck, knives, or something more conventional? (Do they even have designated truck or knife deer hunting seasons in VA? )