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Re: (2025) Smart and/or programable TRVs that function as a flow rate valve and not a thermostat
Theoretically, of course, of course, it's quite possible. In practice, there are some rather interesting difficulties. They lie both in the control logic which is to be followed and in the physical construction of the valve.
Not to say it can't be done. I just don't know of any which do.
Re: (2025) Smart and/or programable TRVs that function as a flow rate valve and not a thermostat
Is this a hot water, or steam application ?
Caleffi has a product with adjustable Cv, in the European market. Not for steam however
hot_rod
Re: (2025) Smart and/or programable TRVs that function as a flow rate valve and not a thermostat
0-10V zone actuator with 0-10V thermostat. If you are into smart home, there is a lot of 0-10v output devices as they are used for dimmers, combined with a room sensor and a bit of coding, you can do your own controls.
https://www.caleffi.com/en-us/thermo-electric-control-valve-actuator-24v-source-0-10v-prop-actuation-nc-6565-caleffi-656524
Kaos
Re: (2025) Smart and/or programable TRVs that function as a flow rate valve and not a thermostat
So it would seem that the hardware exists — the modulating valves (0 to 10 volt). Excellent. And, of course, the sensors, also 0 to 10 volt thermistors.
Which leaves the problem… the software and control integration. Whether you need to run a separate cable to each radiator or not is somewhat debatable; I would at least look into the possibility of a single 4 or more wire (probably Cat 5 or better) cable capable of feeding a digital command and feedback signal to a central processor but also capable of feeding the required power and ground to each unit. I suspect the computing power available in a Raspberry Pi of some flavour would be quite adequate.
The Raspbeerry Pi community is open source — and has extraordinarily wide interests, so it is entirely possible that there may be some code bits which would be usable as part of the programming.
Re: (2025) Smart and/or programable TRVs that function as a flow rate valve and not a thermostat
You don't need to do your own controls. 0-10V thermostats are common in commercial space ie:
Kaos
Re: Air Vent at boiler. Necessary with Air Sep?
Yes, that is what I am suggesting to you as long as you have enough space overhead to install one of the air vents from Mcmaster Carr using a pipe coupler, pipe nipple, ball valve and then the air vent in that order.
A long enough pipe nipple clears the elbow and lets you safely tighten the pipe coupler, pipe nipple and air vent in one operation-if you have a big plumbing supply house nearby they may have a one inch air vent in their inventory and they may very well put the whole thing together for you leaving you to remove the cap after you drain the boiler and use pipe dope for the male threads on the pipe nipple. Do not paint the last thread of the pipe nipple with pipe dope or teflon tape as it will end up in the boiler water and you do not want that to happen as it can cause problems.
leonz
Re: Boiler explosion in White Marsh, MD
I may be wrong but the lack of moisture and the cast appearing intact, it looks like a gas/burner explosion. Glad he survived.
SlamDunk
Re: Changing out a heat pump stand with unit in situ
Thanks for the input and advice!
I have a metaltech scaffold here (the yellow one), and I think the best option would be to set that up safely over the unit, then put a ladder horizontally across the rungs on the two uprights (and lock them into place with clamps), and then attach ratchet straps over the ladder and under the unit on both sides (and maybe add a pair of back-up ratchet straps on the insides of the legs of the heat pump in case of - hopefully unlikely - slippage.
If I do it carefully I think this should work well. As long as there's no swing back and forth as this would make the unit want to pull away from the lines, but correct positioning of the ladder should be able to prevent this.
Re: New Rinnai boiler overheating very quickly but no hot water?
Well… I believe I am looking at the correct manual. Where is the Boiler pump in your install ? It acts like there is no water flow through the boiler. No boiler pump (circulator) #11 below.
109A_5
Re: state 80 gallon electric heater extra charge for instructions
Good morning, folks. I work for Laars. We are asked frequently for conversion instructions and stickers. Either the contractor wants an "official" one from us, or an inspector does. When someone needs an instruction sheet, we offer to email a pdf, but still some people want a "real" one shipped. I know it seems like a very small thing, but there are real costs associated with selling these. Just like contractors have costs that people may not think about like insurance, training, employee benefits, stock, vehicle registration/maintenance, etc. We pay a vendor for these items, and pay people to order them, receive them, store them, pick them, pack them, ship them, etc.. No different than the process to get controls, gas valves and blowers, etc., in house and out to a job.
Anyway…. just wanted you to hear my side of things. Have a great day, and thanks for all you do!
Joannie