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3-Storey Building with monoflo -

drongomaster
drongomaster Member Posts: 6

Hi there,

My condo building is a 3-storey building built in mid 50s. The building heating is done with a single pipe system with monoflo / diverter tees. Suite layout repeats thrughout the floors including the convector locations.

Most of the units in the building are hot and I'm looking to install radiator valves in every suite to allow occupants to control the heat in their suites. I did some research and it sounds like adding the radiator valves to one pipe system with diverter tees should be fine given that these valves have little head losses (large Cv).

I can see 4 pipes in the crawlspace branching off the main loop pipe at the location where radiators are on all three floors - photo is attached below.

I suspect that 2 pipes connect the convector on the main floor and other 2 pipes are feeding the convectors on 2nd and third floors but I'm not sure about it. All the piping is hidden inside the walls and there is no way to find out without demolishing the drywall.

I'm seeking for an advice in case someone had any experience with a similar setup. Also, I would like to find out how the convectors would typically be connected in this location. Below are some photos of the convectors as well as the sketch at this location. Any advice is appreciated. Also, currently, the main floor unit has radiator valves which are mostly closed. Second floor unit convectors are always cold and third unit convectors are always hot. The system is known to have air problems so I suspect that second floor may have air blockage. Second and third floors don't have any radiator valves installed and we would like to add those in. Thanks for your help

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,102

    It's really hard to say how it is piped. Is the main entirely in the basement?? It is more than likely in a building like that that multiple pieces of radiation are piped to each set of tees.

    If every

    floor is the same "cookie cutter" on top of the first floor it will be easier to figure out. Might be something like the attached.

    If the main is all in the basement and you can follow it from where it leaves the boiler to where it returns to the boiler I would start by counting the number of monoflow tees.

    You could have one monoflow tee and 1 regular tee in pairs or they may have used two monoflow tees on each pair.

    Either way if the main is all in the basement and you can figure out how many pairs of tees you have it will make it easier to figure out.

  • drongomaster
    drongomaster Member Posts: 6

    EBEBRATT-Ed, thanks for your input. I also thought that piping is similar to what you've sketched which would kind of be a secondary loop connected to the main loop. However, why there would be 4 pipes branching off the main pipe at this location in the crawlspace? The main loop is indeed in the crawlspace.

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 16,102

    Hard to say how they split things up. A wild guess would be that the first and second floor are on 2 pipes and the third on the other set of pipes.

    Third floor would have the higher heat loss

  • drongomaster
    drongomaster Member Posts: 6

    Do you think we can install radiator valves on every radiator without causing any issues with the flow into other radiators?

  • DCContrarian
    DCContrarian Member Posts: 503

    If you just put in manual balancing valves, each valve is going to affect the flow to other radiators and it's a game of whack-a-mole to get it to work. With thermostatic valves you should be able to get them to react automatically.

    If you have a wall thermostat it has to be in the coldest part of the building, what you don't want happening is the thermostat to be satisfied when somewhere else in the building needs heat but can't get it. With monoflos you can get rid of a wall thermostat, have the circulator run all winter and the thermostatic valve on each radiator control the flow in that room.

  • Big Ed_4
    Big Ed_4 Member Posts: 2,929

    To make it work on a mono flow without affecting the main flow, you will need to install three way valves between each set of risers ….

    There was an error rendering this rich post.

  • drongomaster
    drongomaster Member Posts: 6

    I see the logic in what you are saying: the flow is proportional to pressure difference so if one radiator on a secondary loop has its valve partially closed, the other radiator may or may not get more flow coming through it. What I'm worried about is let's say I have two radiators in parallel on a secondary loop and if one of the radiators is closed now the flow needs to make it through one remaining radiator which would result in more resistance to the flow. Can this resistance cause the water stop flowing through the secondary loop all together?

  • drongomaster
    drongomaster Member Posts: 6

    What are consequences of affecting the main loop? Will the pressure rise if a secondary loop is blocked and that may affect the pump operation due to high pressure in the system?

  • DCContrarian
    DCContrarian Member Posts: 503

    On a secondary loop the radiators are all in parallel, one TRV closing doesn't prevent flow in the rest of the loop. If all of the TRV's on a secondary are closed, there is no flow in that secondary. That's where the monoflos come in, they allow flow to continue in the primary.

  • Big Ed_4
    Big Ed_4 Member Posts: 2,929

    Restricting a mono flow system effects the whole system in a negative way . The water running through the main powers the system with the vanturi tee creating pressure drops . . If a riser is capped or closed off . The dead vanturi tee will only add resistance to the flow of the main , flow will drop and decrease the pressure drop at the other tee's….

    There was an error rendering this rich post.

    EBEBRATT-Ed
  • drongomaster
    drongomaster Member Posts: 6

    Those are all valid points you guys mentioned. I think I have a plan in mind: I can install 3-way valves before the radiators with one outlet shut closed. This way the valve will work as a typical 2 way valve. In case this will cause issues with a system, I will add a bypass pipe to a previously shut closed outlet. Any feedback is welcomed. Thanks