gshp in florida ac only - Page 5

AC_Hacker · 01-08-12, 05:50 PM

Quote:

Originally Posted by rhino 660

i need help figuring out how much resistance my pump will encounter in my system so i can buy a properly sized pump.

I think I can help you out, but I need to know the actual ID of your loop pipe.

I worked with a couple of different brands of pipe, both nominal 3/4" and each with a different ID, enough to matter, so I need to know the actual ID. If you can get a digital caliper and measure in the max diameter axis and also in the minimum axis, and post those values, I think I can help with the rest...

-AC

rhino 660 · 01-08-12, 07:09 PM

its .845-.860 thank you very much

AC_Hacker · 01-10-12, 01:39 PM

rhino,

OK, here's a document that is put out by Taco (pronounced: TAY-ko).

http://www.taco-hvac.com/uploads/Fil...irculators.pdf

Read it over a few times and see if you can follow the procedure. Let me know if you have questions.

on Table three, there are various values for "k" which is a constant that will be used to calculate friction, or head loss (same thing expressed another way).

They don't have a value for k that corresponds to the diameter of 3/4" HDPE, so I calculated it for you, and that calculated value is 0.0031.

You should calculate the head loss for one loop, using the k value I provided.

From that you will know what pump to use.

But since you are running three loops in parallel, your head loss will be less (about 1/3).

Also, since your loops are in parallel, when you pump the required quantity, in gallons per minute through the pipes, your fluid velocity will be lower (about 1/3).

Since the power required to pump the fluid through the pipes is a product of the square of the velocity, pump power will be smaller.

Go ahead and do your best, I will also, and we can compare our results.

-AC_Hacker

rhino 660 · 01-14-12, 10:06 AM

ac hacker i came up with 18.21' head for the loopfeild
.0031x1.095x700x23.002/3=18.21' head

31' of 1 1/4'' +all fittings (29.9') 60.9 equivalent feet of pipe
0.00032x1.095x60.9x23.002= .49' head

3 3/4'' ball valves = 3.6 foot of pipe
.0031x1.095x3.6x23.002/3= .093' feet of head

coil water pressure drop
at 6.0gpm 2.3 psi 5.3ft head
total foot of head
18.21+.49+.093+5.3=24.093' head for the whole system + what ever the pump creates

rhino 660 · 01-14-12, 10:08 AM

do you concur also thanks for the link

rhino 660 · 01-15-12, 10:01 AM

would you consider the tees in my manifold branch or flow thru

rhino 660 · 01-15-12, 10:34 AM

Taco Pumps Circulating Pump / Motor Unit, Stainless:: 1/8 HP, 0-28 GPM - Dultmeier Sales

this pump appears to fit my needs but kinda expensive

AC_Hacker · 01-15-12, 11:23 AM

Quote:

Originally Posted by rhino 660

would you consider the tees in my manifold branch or flow thru

It would depend on the usual direction of the flow through the "T". If the usual direction is across the top of the T, it would be flow-thru, if it takes a turn, consider it a branch.

With 24 feet of head (or what ever the number comes to) the difference in additional head loss would fade into insignificance.

I think your total head loss seems kind of high... I still need to do my calcs.

The pump you mentioned is stainless. Do you know that you require a stainless pump? Or how about a bronze pump?

If all of your loop field is plastic, you might even be able to get away with iron. Do you know if you have any other metal components that the loop water comes in contact with? What is you HX made of?

-AC_Hacker

rhino 660 · 01-15-12, 11:40 AM

Cupro-nickel coaxial heat exchanger or copper most likely copper so brass would work fine
i emailed grundfos pumps about there ecm driven pump. dont know the price yet

rhino 660 · 01-15-12, 09:22 PM

the two connections here are for the pump from the makeshift tank and the heatpump return to the loopfeild also temp ports the pipe on the far right is the condensate drain that heads outside

this is the feed from the loopfeild into the tank where air is removed also note the temp port

01-10-12, 01:39 PM	#43
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	rhino, OK, here's a document that is put out by Taco (pronounced: TAY-ko). http://www.taco-hvac.com/uploads/Fil...irculators.pdf Read it over a few times and see if you can follow the procedure. Let me know if you have questions. on Table three, there are various values for "k" which is a constant that will be used to calculate friction, or head loss (same thing expressed another way). They don't have a value for k that corresponds to the diameter of 3/4" HDPE, so I calculated it for you, and that calculated value is 0.0031. You should calculate the head loss for one loop, using the k value I provided. From that you will know what pump to use. But since you are running three loops in parallel, your head loss will be less (about 1/3). Also, since your loops are in parallel, when you pump the required quantity, in gallons per minute through the pipes, your fluid velocity will be lower (about 1/3). Since the power required to pump the fluid through the pipes is a product of the square of the velocity, pump power will be smaller. Go ahead and do your best, I will also, and we can compare our results. -AC_Hacker __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker... Last edited by AC_Hacker; 01-10-12 at 01:44 PM..

01-08-12, 07:09 PM	#42
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	its .845-.860 thank you very much

01-14-12, 10:06 AM	#44
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	ac hacker i came up with 18.21' head for the loopfeild .0031x1.095x700x23.002/3=18.21' head 31' of 1 1/4'' +all fittings (29.9') 60.9 equivalent feet of pipe 0.00032x1.095x60.9x23.002= .49' head 3 3/4'' ball valves = 3.6 foot of pipe .0031x1.095x3.6x23.002/3= .093' feet of head coil water pressure drop at 6.0gpm 2.3 psi 5.3ft head total foot of head 18.21+.49+.093+5.3=24.093' head for the whole system + what ever the pump creates

01-14-12, 10:08 AM	#45
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	do you concur also thanks for the link

01-15-12, 10:01 AM	#46
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	would you consider the tees in my manifold branch or flow thru

01-15-12, 10:34 AM	#47
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	Taco Pumps Circulating Pump / Motor Unit, Stainless:: 1/8 HP, 0-28 GPM - Dultmeier Sales this pump appears to fit my needs but kinda expensive

01-15-12, 11:40 AM	#49
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	Cupro-nickel coaxial heat exchanger or copper most likely copper so brass would work fine i emailed grundfos pumps about there ecm driven pump. dont know the price yet

01-15-12, 09:22 PM	#50
rhino 660 Apprentice EcoRenovator Join Date: Oct 2010 Posts: 105 Thanks: 0 Thanked 10 Times in 8 Posts	the two connections here are for the pump from the makeshift tank and the heatpump return to the loopfeild also temp ports the pipe on the far right is the condensate drain that heads outside this is the feed from the loopfeild into the tank where air is removed also note the temp port