Piping to fintube baseboard

Mattr1

Thanks Brad.

My scenerio is on a new zone loop to an addition. It is serving two rooms. You bring up a good point about piping it as a normal circuit (I suspect you mean a one pipe series circuit) but the only reason I considered modeling it after the design of the other zones is because I can use TRV valves to lower the heat output of one of the rooms (it will not be used right away).

All that being said, would you have any concerns with the piping description above and its effect in relation to the diverter tee?

Mattr1

Piping to fintube baseboard

I am installing hot water fin tube baseboard in an addition. The design of the new zone will match that of existing zones: one-pipe with diverter tee on the return leg of the branch circuit. The diverter tee size is 3/4 x 1/2, meaning the branch circuit piping to the fintube will be 1/2". My local Big Box store only sells 3/4" fin tube baseboard. Is it o.k. to use 1/2" pipe from the supply tee, up to 3/4" fintube, then 1/2" back to the diverter tee? I know the diverter tee works by creating a pressure drop in the line thus allowing the flow through the branch circuit. Are there concerns with pressure changes in the branch circuit if piped the way I propose and its effect on the diverter tee?

Thank in advance

Brad White_9

Danger, Danger Will Robinson....

If the 3/4 x 3/4 x 1/2 diverter tees are in addition to others existing you may be imposing too much pressure drop on that loop.

Bell and Gossett at least limits the number of monoflow tees of that size to one or two per circuit I believe. (One tee or one emitter, I forget which). The reason they have them at all is to allow a "slave" element off of a primary, not as a "main with lots of branches" arrangement. The ratio of free area remaining is pretty tiny.

Why not pipe it with a normal circuit? No need to replicate what is there necessarily. All systems have their limits.

My $0.02

Brad

Brad White_9

If you are

Just using one branch off a primary circuit as you describe, Matt, no, I do not have a problem with that. TRV's? Perfect in the slave zone only. There should be inherently be a bypass with the Monoflow main path.

Originally I pictured another addition to the original circuit. If the circuit were split parallel not in series I would not worry about it either.

CHARLES_4

TEEs

So why not use a straight 3/4" monoflow tee? I'd be worried about the reduced gpm @ 1/2" and the the pressure drop going back to 3/4". Sounds like you're on track to turn this into a nightmare...

Brad White_9

Good point

No reason why not unless that size tee is not available.

Couderay

According to what i've seen as far as monoflo tee's they are always reduced on the bull but one could get a 1" monoflo tee and reduce the runs to 3/4"

Mattr1

TEEs

The monoflo tee is only available (that I have been able to find anyway) as 3/4 x 1/2, not 3/4 x 3/4. In addition, the 1/2" line provides the correct flow to the branch. A 3/4" branch would almost triple the flow through the branch. Per Charles' comments about pressure drop going back to 3/4" it looks like I need to find 1/2" fintube