Trouble with Baseray conversion

Chuck_12

Simply put... I replaced a 16 fin three col cast iron rad 23" high with a new 12' section of cast iron Baseray. The supply pipes remained the same which were 1" galv off a 1-1/2" main. My problem... the baseboard rad does not heat well. Flow seems restricted due to other rad lines heating up more rapidly than this run. From the main I have approx. 20' of 1"supply to 12' baseboard and then return with approx 12' of return. (8' differential) Also keep in mind the static flow of the new rad compared to old column type. Several things may be happening here... other lines from the "Main" heat up fully at boiler temp and therefore the return (when hot) then restricts the cooler flow return from the baseboard line. Hence...slower (or restricted) flow and cooler baseboard rad. The pitch of my piping is fair but due to the new longer run of 8' supply, the pitch is less. Does that matter? Any suggestoins to help me along to get flow back to this radiator? I prefer NOT to use seperate circ pump for just one rad run. Any suggestions? I am guessing that I need to somehow get the baseboard rad run to heat closely to the temp and time frame of the other rad runs to prevent the cold/hot water bucking each other on the return line. Would a mono flow valve solve this, better pitch of lines? Shorten the length of the supply from main to the Baseray so hot water enters sooner? Help!

Added note: the system has been thoroughly checked for leaks and importantly air in the system. If you take into account the overal capacity of the Baseray per sq.ft. vs the older radiator water capacity per sq.ft.; then naturally the older rads will heat quicker; and hopefully there is a way to compensate by either modulating the flows thru valves of alternate pipe sizes? Also..Can water be naturally forced to flow faster by increasing the pitch of pipe at the horizontal runs off the mains? (and not increasing the water temperature at any time to compensate) I want to maintain 180 degrees IN and approx 150 degrees min OUT (return to boiler)

Big Ed

System

I have a feeling you have a old gravity or converted gravity system. Yes the change in the piping and the longer radiation is your problem. Pitch of the riser is very important. Longer risers without added hight decreases flow. Move the tees on the main a distance of the radiation to correct problem.

Now food for thought ........If the EDR of the new radiation is less then the original pulled out , it's room will be colder. The tees a bit of work to space?? You want to use the new radiation?? I would look to zone that room now.......

Chuck_12

confirmed! - modified gravity system

the system had a circ pump added on the return at teh time the boiler was converted to Gas blower type. The overall balance was great on the system prior to the Baseray modification. So I see several things to take into consideraiton; a) the new added run of 10' of 1" supply due to longer baseboard rad.; b) the Baseboard inlet is 3/4" vs the old rad was 1" inlet; c) the new valve is 3/4" vs. 1"; and d) the pitch of pipe is slightly more level on the supply and return piping. Overall I think these factors have lowered the flow of this line off the main prior to the old install. I want to compensate if I can without installing a seperate circ pump. One option I have is tapping into the supply and return at the first elbow turns of the "mains" off the boiler which may give me the "hottest tap" to compensate for the longer run; however I would be limited to a 3/4" line. (even Burnham recommends use of minimum 1" line for 10-12 feet baseboard on a gravity system for the 1st floor radiator install) Please comment.

By the way; the EDR is sufficient for the heat load. Prior was 60BTUH and now needed is only 40BTUH (insulation and replacement windows were installed)

Big Ed

Single zone

Sure the house as a whole has been tighten but the other radiators are producing at it's original out put under the new roof....

You can install a parallel loop but add a throttle valve or better yet a trv for control.

6800 btuh at 180* , 1/2" line is more then you need...

Chuck_12

thankx Ed

matching the flow of the Baseray wont be easy if even possible. I have a return circ pump as noted but do not want to use a seperate loop pump; id rathr increase the pipe size and hold back on mechanics. I'm afraid to say however, the 1/2" line wont work for gravity feed. Back to my drawing board. Thankx Ed.