In need of hydronic help!!

[tstewart2]

So I had this system installed in my new shop last year and something seems like it is just not quite right. My shop is 26x32 10' ceilings with steel exterior 3" spray foam in the walls and 3/8" dairy plastic For the interior finish. 5" concrete floor with foundation that has 2" rigid insulation underneath and as a border....she was built right.I used a 50 gal hot water heater 3/4" copper loop with a taco 006 pump and 5000 series mixing valve, 4 loops with 1,000 ft of 1/2" pex in the floor. I have moved the pump to directly below the mixing valve(not shown in pic) but the system seems to run for very long periods of time, burn a lot of natural gas and something just is not right. Suggestions????

 

[nadogail]

Did the system work to your expectations prior to it's modification?

Have you analyzed the flow rates and temperature differentials on your four loops?

 

[Rnbuck01]

How come is there a valve right above your mixing valve?

 

[kj_mustang]

What is the gpm flow rate on the flow meters at the supply manifold? What is the water temperature at the supply manifold?

 

[pstnbly]

If the WH is running constantly and you are not reaching the set point in the building the output of the WH is too small for the load.

 

[finn]

Where are you located and what is your slab temperature?

It will take a long time to bring a 5"slab from 40 degrees to 65 degrees, and a lot of natural gas. Once you reach the target temperature the system will run only enough to replenish the heat loss through the building doors, windows, walls, and ceiling.

 

[LS6 Tommy]

250' loops seem kind of long. I could be wrong...

Tommy

 

[86turbodsl]

250' loops of 1/2" pex is just right. I can't tell from the pic what he's doing wrong. Need better pictures to help.

 

[nadogail]

Original Poster has not answered any of our questions, maybe OP found and fixed some embarrassing simple cause to their problem.

 

[larry4406]

First post and done?

 

[dfiler2]

Maybe, but as mentioned above, there could be nothing wrong with the system that would cause the building to take too much heat as long as all the BTU's from the water heater are going into the building.

 

[tstewart2]

Not the least bit embarrassed, travelling for work.

Flow rates and temper differentials are all within spec as well as the loop sizing and length....I had the loop size and spacing engineered by supplier for this building with heat loss calcs.

Water heater is capable of 30,000BTU and system load requires 22,000.

The valve above mixing valve is for a bypass and really doesn't have much of a purpose.

I am located in southwestern Ontario, very similar conditions to all you guys posting from Michigan.

One part of the system I am unsure of is the "boiler loop" as I previously stated, the "floor loop" was engineered and designed, not the "boiler loop" for a desired head pressure and such, perhaps this is making things funky and water is simply travelling through the floor and directly back to heat source instead of being mixed and recirculated back to floor

 

[Boneheads Garage]

Your gpm is ok at the tank heater? My circ pump lost prime this year so I added about 1/2 gallon of water and purged a slight amount of sit to make the pump start circulating again.

 

[tstewart2]

I would think the GPM is okay returning to the water heater? No way to tell really the flow meters are positioned on manifold where water enters the floor loops

 

[Boneheads Garage]

you need to verify somehow that the pump is moving liquid. Mine runs at 1.4 gpm.

 

[nadogail]

Did the system work as designed prior to the modification?