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Smart TRV

madapanmadapan Member Posts: 5
edited January 3 in Strictly Steam
Hey Everyone!

I'm at the very early stages of developing a smart one-pipe TRV to reduce overheating. What do people think? Is there demand? Issues / Challenges?

Comments

  • JUGHNEJUGHNE Member Posts: 5,648
    Can you define "smart"?
  • SailahSailah Member Posts: 791
    "Hey Alexa..."
    Peter Owens
    SteamIQ
  • nicholas bonham-carternicholas bonham-carter Member Posts: 7,824
    If your system is balanced properly, with good main venting, and low pressure, all the radiators will heat at the same time.
    As a result, there should be no localized overheating.
    Often TRV’s are used as a bandaid for dealing with bad venting, and thermostat placement. In the end, the solution defaults to getting the system back in balance, and that’s where the “smart” comes in-not from a mechanical add-on, but from diagnosing any system faults, and then performing subsequent remediation.—NBC
  • madapanmadapan Member Posts: 5
    Thanks Nicholas. Totally understand the bandaid issue, but wonder if a better bandaid has any merit.

    To address the "smart" question above. Yes, we are thinking of including all of the things that make smart home tech cool and user friendly - app based interface, connectivity, compatibility with other smart home integrations (ie. Alexa, Google Home, IFTTT). But the main "smarts" come from the ability to learn and optimize based on how the room is responding to the heat - taking in indoor and outdoor environmental data to change home much air needs to be kept in the radiator
  • ChrisJChrisJ Member Posts: 9,666
    I'm using 5 TRVs on my single pipe system in a single family house.

    I don't use them for overheating issues, as much as allowing the system to compensate for changes in the environment. Like, the sun warming rooms up during the day, or the oven going in the kitchen etc.

    That said, my wishes would be a digital thermometer along with a digital set point with a remote sensor rather than a simple wax motor right by the wall. The sensor being right by a cold wall and sometimes hot radiator is the biggest issue IMO.


    Your TRV needs a decent vacuum breaker and the ability to change it's venting capacity either through a variable vent like the Vent Rite 1, or being able to change vents via an 1/8" NPT port.

    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • madapanmadapan Member Posts: 5
    Thanks @ChrisJ! I think you've hit on a few of the critical needs for this type of product - remote sensor and changes in the environment.
  • EastmanEastman Member Posts: 927
    Will these smart TRV's be able to call for heat?
  • ddunnddunn Member Posts: 12
    How would it distinguish from existing https://www.amazon.co.uk/Electronic-Radiator-Thermostat-Programmable-Thermostatic-x/dp/B01N35O95F

    Compare with other similar options shows four items that seem similar to your proposal.
  • gennadygennady Member Posts: 732
    Bad idea. In steam systems boiler works on thermostat or outdoor reset. Radiators act as accumulators of heat. They are charging and discharging. It is cyclical process. With “smart” trv system will fall out of cync with boiler.
    Gennady Tsakh



    Absolute Mechanical Co. Inc.

    www.AbsoluteMechanicalCoInc.com
  • mikeg2015mikeg2015 Member Posts: 785
    If you had a totally sealed system you could use an EEV to control boiling rate, control a modulating burner off superheat, then use zone valves to control radiator output. Would work better on a 2 pipe system.
  • EastmanEastman Member Posts: 927
    edited January 8
    The TRV's shouldn't rely on a thermostat. Collectively, they should be deciding when to fire the boiler and for how long.
  • ChrisJChrisJ Member Posts: 9,666
    > @gennady said:
    > Bad idea. In steam systems boiler works on thermostat or outdoor reset. Radiators act as accumulators of heat. They are charging and discharging. It is cyclical process. With “smart” trv system will fall out of cync with boiler.

    Eh?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • hvacfreak2hvacfreak2 Member Posts: 474
    Eastman said:

    The TRV's shouldn't rely on a thermostat. Collectively, they should be deciding when to fire the boiler and for how long.

    Yeah a networked system of these would be fantastic. Back to a main controller to allow group assignment and logic. It would be nice to be able to force the positions ( close upstairs zones to x percent until first floor zones are at x degrees if the outdoor temperature is less than x ). And floor plan graphics since I'm dreaming , lol.
    hvacfreak

    Mechanical Enthusiast

    Burnham MST 396 , 60 oz gauge , Tigerloop , Firomatic Check Valve , Mcdonnell Miller 67 lwco , Danfoss RA2k TRV's

    Easyio FG20 Controller

  • EastmanEastman Member Posts: 927
    @hvacfreak2

    Like you said, the TRVs should have a main controller for group assignments, etc. But it is my hope that this main controller would also be in charge of CPH and pressure. I also think temperature sensors on the end of each main would be helpful.
  • Jamie HallJamie Hall Member Posts: 10,383
    Keep in mind -- firmly -- that steam heat (any heat, for that matter) is a system, and all the bits must work together in some sort of harmony.

    I think that there is some merit -- in fact, probably a good bit of merit -- in having thermostatically controlled valves for the individual radiators in a two pipe steam system (not in one pipe -- condensate problems, unless the valves are really tight) -- but only as part of a complete control system. Think of it this way: the boiler is in charge of supplying the heat transfer medium (steam at some temperature) and must also be controlled to provide that medium in the right amounts at the right temperature.

    So... if we are going to leave the ultra simple and reliable world we usually work in, where do we go? Well, the TRVs control the individual radiation, but they are expecting to have the transfer medium always available. So the boiler is controlled, within a narrow but adequate pressure range, by a pressure controller. If we really want to get fancy, we can seal the system and provide an induced vacuum, controlled by an outdoor reset, to vary the temperature of the steam which we are supplying (note that this also implies that the target pressure for the pressure controller is also controlled by the outdoor reset. The TRVs can have very narrow deadbands, to maintain steady temperatures in the space -- or could even be proportional if the valves can do that. The pressure control system can have a much wider dead band, to minimize boiler cycling (and could be tied into the burner control, if the burner can modulate).

    There are some rather interesting potential feedback loops here, which would make programming the controller for such a system much more interesting and would require considerable expertise in setting the system up, but that's doable.

    It would also be possible, with a few additional controls, to make the whole thing fail operational (like the limp home mode on a modern car).

    Is it worth it? A resounding maybe... unless you can operate much of the time at a high enough vacuum to make the boiler condense -- and the boiler is designed to do so -- the gain in thermal efficiency will be small. The gain in comfort in a relatively small building will also be small. But in a bigger building it might be worth it. There would be, of course, a real increase in maintenance involved, and the person in charge of keeping it running would have to be well paid for their training and knowledge -- not a trivial item.

    Random thoughts of a Wednesday morning...
    Jamie



    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.



    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • hvacfreak2hvacfreak2 Member Posts: 474
    I guess what I would want is just a proportional ( or pulse ) motor for an actuator. I would connect it with that small chrome armored cable like door contractors use to a controller like this one ,

    https://easyio.eu/benefits-of-the-new-ft-04/

    This controller would need a wired 24 volt power supply as well as a wired stat ( or a wireless with a receiver unit ). It is only 2 x 3 inches so it could be incorporated onto the actuator or maybe placed in a wall with an antenna extension for the wireless comm. After that it could be as simple or as complicated as needed , controlled from a phone or integrated into a BACnet / ip network.

    hvacfreak

    Mechanical Enthusiast

    Burnham MST 396 , 60 oz gauge , Tigerloop , Firomatic Check Valve , Mcdonnell Miller 67 lwco , Danfoss RA2k TRV's

    Easyio FG20 Controller

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