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1 Boiler - 2 Zones - 2 Bills

JStar Member Posts: 2,752
So, I get a phone call today from a customer who owns the store front attached to a 2nd floor apartment. The landlord just had somebody replace the boiler. The landlord wants the store owner to pay for 66% of the gas bill even though they use the least amount of heat (freezer compressors dump a lot of heat into the store).

So, I had this vision of splitting the gas line to the boiler with separate gas meters and solenoid valves that would be energized by the individual zones. Does this sound practical or possible? The piping would have to be symmetrical to be accurate. Do you think, if both solenoid valves are open at the same time, that the meters would read the same CFH or the total CFH divided in half?

Most importantly...is there an easier solution? I've been researching BTU meters for the hydronic lines, but (hate to say it) they are damn expensive!


  • furnacefigher15
    furnacefigher15 Member Posts: 514
    Bad Idea

    What kind of zoning is used on the boiler?

    May be very easy to add a simple timer that runs when ever the respective thermostats are calling for heat.

    Then just dived the gas based on run time demand %.


    zone 1 called for 600 minutes of heat in the month

    zone 2 called for 1200 minutes of heat in the same month

    So zone 1 gets 1/3 of the bill

    and zone 2 gets 2/3 of the bill

    Would require a strict implementation of checking the timers on the same day each month.
  • JStar
    JStar Member Posts: 2,752

    I also was leaning towards a timer. Didn't know of a particular type that would do it. Plus, run time of the zones doesn't necessarily reflect the burner run time. Zone 1 could heat the boiler, then zone 2 pops on and steals all the heat "for free". And the zones would be on the clock if the boiler ever shut down on safety or another failure.
  • furnacefigher15
    furnacefigher15 Member Posts: 514
    It's not

    About burner run time, just demand time.

    Regardless of if the boiler was already on to be running zone 1, zone 2 will have a timer tracking its demand also, so it would not be "free".

    You could even weight the demand if one zone is bigger than another.

    if the heat is broken, then there would just be more demand time for both tenants, and the math should work out the same.
  • meplumber
    meplumber Member Posts: 678
    btu meters

    I have done quite a few commercial spaces as you describe where we used btus meters.

    They are a clear answer to the old question of "How much do I use?"


    These are the ones that we have been using. A little more pricey than a timer, but much more accurate.
  • JStar
    JStar Member Posts: 2,752

    I found those as well. My question was, do they just calculate the amount of BTUH in that one zone, or do they actually tally up and keep track of how many BTU's are being delivered over time?
  • meplumber
    meplumber Member Posts: 678
    btu meters

    Those have a running tally of actual btu's used over time for that particular zone. I think that they can be reset, but I have never done it. Most let them tally, like an electrical meter, and simply take the reading on the same day each month.

    The buildings that I have put them in are like you describe. At the end of every month, the landlord or his rep, takes the reading on the meters. They then divide the heating bill for the building accordingly.

    I have one building with 9 of them in it, and a couple of buildings with only 2.

    They are a little pricey, but it provides a definitive answer to how much each zone uses. It takes the guess work out of it and should there be litigation from a tenant, they provide a clear cut way of monitoring usage.
  • Steve_210
    Steve_210 Member Posts: 637
    How pricey

    Is pricey. I have a few jobs where these could work well.

    Any problems? We are very apprehensive when it comes to using new products.
  • meplumber
    meplumber Member Posts: 678

    Pricey is a relative term. They are aren't bad. If you are installing several of them in the same basement, it is pretty decent per zone. The selling point is the headache and liability that it takes off of the landlord. A btu is a btu. So it takes the guess work out of it. As long as they can operate a calculator, it simplifies the process.

    They aren't new. I have a few of them that have been in for 7 or 8 years. The only problems that we had were self induced. I put some in about a month ago, so I am still using them.
This discussion has been closed.