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Old 07-05-13, 09:15 PM   #39
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Originally Posted by dremd View Post
What GPH / GPM would you recommend for a 8k Compressor with that exchanger? I had 500 GPH on the mind, but I have no idea where I got that ida from.
I got 'bit in the butt' by having too much resistance to fluid flow in my loop field. I learned the hard way that given enough pump power, you can force enough water through your system to make it yield enough heat... but there is a price to be paid in the pumping energy. A properly designed loop, with minimum resistance (AKA: head) will require less pumping power. Therefore the entire system will be more efficient. I ended up digging up some pipe and splitting my loop filed in two loops in parallel, to reduce my pump power loss to one quarter of what it was previously.

I do realize that you are doing a pump and dump, so you don't need to contend with the relatively complex field like I had... and your pumping power will surely be less.

But if you haunt the Taco Pump pages, there you will find the tables and formulas you need to calculate the head loss of your system, based on pipe diameter, pipe length, fluid velocity, fluid viscosity, and the number and size of any restrictions in your system (I believe that the 5/8" tube entrance may be a restriction).

BTW, the flow rate rule of thumb fro GSHP is 3 gpm per Ton... and as a rule of thumb it is just the first-cut estimate, and not the final design criteria.

I'm not an HVAC technician. In fact, I'm barely even a hacker...
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