Radient Floor Circulator

brucewo1b

Frank how about a picture of the pipng layout from the boiler to the where it connects to the infloor loops and back to the boiler.

frank_32

Radient Floor Circulator

I recently was on here asking about how to fix the problems with my radient floor heat in my concrete basement floor. I believe I have narrowed it down to a couple factors that I need to address. First is the fact that the block basement block walls are not insulated nor is the concrete slab between the wall and the slab. Secondly is the size of the circulator pump used on the radient floor loops.

I read the article on "How to Size Circulator" and think that I am understanding that my problem is that the pump head is not enough for the longest loop in my floor. If I understand the article correctly, I do not have the right size taco pump. I currently have a Taco 007 pumping the water thru 5 1/2" loops of pex equalling 1343' of total tubing. The longest loop is 356' long and the next in line is 309' long. There is a third that is almost 300 and then the last two are around 200' each. The last two lines always seem to heat up quick but the other three longer lines never seem to warm up.

If I understood the article correctly, I should figure out my flow needs, which I don't know if it's based on the overall size of 5 1/2" lines=2.5" or the size of the manifold pipe where the loops start. I then understand that I take and figure about 6' of head per 100' of the longest loop. Am I figuring this correctly? I came up with 21.36' of head needed for the longest loop. If I then cross that over to the appropriate taco pump, that would equal a Taco 009. I hope that I did that correctly.

If there is anyone that could help me with this I would greatly appreciate it. I don't have the exact loop lengths here with me but will have them available if someone needs them. Thanks for any help.

Frank

[Deleted User]

Flow...

is based on connected load. You have to do a heat loss to be able to determine load, and subsequent flow. If you go to Bell and Gossets web site, they have an online pressure drop calculator that can calc the actual head.

Also, some of your circuits are approaching and exceeding the maximum recommended length of 300 feet. THis will cause a greater drop in temperature resulting in less heating at the end of the loop.

Remember that water is wet lazy and stupid, just like my ex brother in law. The 007 may in fact be capable of moving the required flow, but it is short circuiting through the shorter loops. If you can restrict the flow through the shorter loops, and shunt more flow into the longer loops, your problems MAY gp away. Got balance valves?

ME

frank_31

Mark,
Thanks for the response. I figured it couldn't be as easy as it seemed. Loved the ex brother in law comment. I got that loud and clear. Are balance valves the brass little valves that are at the beginning or end of the pex tubing? If so they are at the end of the loop. I closed the two shorter loops the other day and let the system run for about 4hrs and actually started to get some heat in the return side of the loops. Just seems like the floor takes forever to warm up then shut off. Then the next time it kicks on, it pours cold water into the system for an extended period of time, wrecking havoc on the rest of the house.

Since the circuits are above the maximum recommended length, would slamming the water thru with a bigger circulator pump keep the temps from dropping so much? Wuold there be enough radiation with the water moving that fast?

I'll have to check the website you provided. I have a heat loss done for the basement and I'll have to pull it out. Unfortunately I have to learn all this so I can stand up to the contractors that tell me "oh nothings wrong with your heating system." Wish they would have been there the other night when it was -12F outside and my room and my baby's room were 60F.

Thanks for the help.

Frank

Steve_35

What sort of floor covering do you have in the problem areas?

Mellow_2

could you ?

do some constant circulation with the radiant floor. This can stop the slug of cold water back to the bioler. You would need a good bypass line to protect the boiler and keep the loop at the right temp anyway.. I have found once the floor warms up the supply and return temps can be realy close in temp and the room is more comfortable.

frank_31

I have never thought about that and no one I have consulted has talked about it. I could definately suggest it to them. Unfortunately I am clueless when it comes to this hydronics stuff. I am slowly educating myself.

Frank

frank_31

I have bare concrete floor in about 90% of the basement. In one spot where there is a small patch of carpet that my kids play on.

Frank

frank_31

Pictures

Bruce, here are some pictures of the piping for my propane boiler system that has the plate heat exchanger plumbed into it for my outdoor wood boiler. I hope that you can see what you might be looking for in the pictures. If not I have a ton more pictures from every possible angle.

Frank

Tom R.

Bottleneck

Picture 2443 - looks like the mixing valve is a pipe size smaller than the connecting piping.

frank_31

Tom, I see what you are talking about but I don't know exactly what it will affect. Could you expand on that thought? Thanks

Frank