Add radiator bypass in series loop system

samurainstein

Hey there Heating Help folks,

I'm hoping to get some expert opinions a remodel situation. I'm doing a complete demo and rebuild of one of our bedrooms. It has Base ray cast iron baseboards along one of the walls (I'm in a Philadelphia row home - baseboards are along a brick party wall). While I'm remodeling the room, I have the cast iron baseboard pulled out. The Hydronic system is a simple series loop, so while this baseboard is out, I have the sytem drained and turned off. Thing is, weather is starting to get cold, and this remodel is probably going to take me another 2 months (+2 more months for wishful thinking). I need the baseboard to stay off cause I will need to frame, drywall, install flooring, etc, but I will probably need to refill and turn the system back on soon. I'm trying to plan out a modification so that I can get the system back on, with the baseboard off. 

Is this an appropriate use case for the monoflow tees to bypass the radiators? It's a 3/4" copper main. Was thinking of converting to 3/4" oxygen barrier Pex for any replaced/new sections, using expansion fittings. I tend to see 3/4" x 3/4" x 1/2" monoflow tees, so was planning on using that sizing. I understand that there's pressure drop to consider in this situation, and the pex inner diameter is slightly smaller than copper. Not sure if this conversion warrants a recalculation of the components, or if it "should be fine". As of now, the system works just fine. 

This is a 2nd floor bedroom, and it seems like the simplest way to get to the piping is to cut open the living room ceiling from below. Open to other ideas! Here's some crude drawings of the space, and what I'm thinking. Long term, I'd like to remodel other bedrooms, and likely want to install a similar bypass on those radiators as well.

pecmsg

just cut the sub floor and work from the top.
unless you’re going to be doing work downstairs why disturb the sheet rock

EBEBRATT-Ed

I would put a bypass between the two existing rad connections in the basement with a ball valve installed in the bypass.

Then either plug or put valves on the two rad connections. Fill the system with the baseboard disconnected and the bypass open and run it. When you reconnect, the baseboard just keep the bypass shut.

Don't get involved with monoflow tees if you don't have to, they just cause issues.