Help-Calculating Head Loss For Pump Selection.

[Sawyer]

I am trying to calculate head loss on my system. 175” of two 1” HePex lines each for supply and return, starting and terminating at the Garn with a 1 ¼”x1”x1”. And the same fittings at the 5x12x50HX. I added 25’ of length for fittings.

I was not able to find calculators that agree on head loss, perhaps it was due to my unfamiliarity with the programs. I calculated 8-16.6 feet of head using various tables and calculators. Taco’s Taconet 7.0 seemed to give me a good idea of head loss if I am using that program correctly in the absence of a pex pipe and using various pipe categories. It seems the head will be between 10-13 feet and that the pump should be similar to a 0011 if I understand this program correctly.

I am asking if I am doing this correctly. I have read every forum post I could find in a search for head loss but I was incapable of coming up with my own figures I could trust.

Thanks, George

 

[heaterman]

I am trying to calculate head loss on my system. 175” of two 1” HePex lines each for supply and return, starting and terminating at the Garn with a 1 ¼”x1”x1”. And the same fittings at the 5x12x50HX. I added 25’ of length for fittings.

I was not able to find calculators that agree on head loss, perhaps it was due to my unfamiliarity with the programs. I calculated 8-16.6 feet of head using various tables and calculators. Taco’s Taconet 7.0 seemed to give me a good idea of head loss if I am using that program correctly in the absence of a pex pipe and using various pipe categories. It seems the head will be between 10-13 feet and that the pump should be similar to a 0011 if I understand this program correctly.

I am asking if I am doing this correctly. I have read every forum post I could find in a search for head loss but I was incapable of coming up with my own figures I could trust.

Thanks, George

175 feet? One way or round trip?

Basically you can just do a calc for one circuit and double the flow rate if the circ you're using will flow at that level.

BTW, where are you located in Northern Wisconsin? I made a flying trip through there last week on the way to Minneapolis to pick up 1200' of 1-1/2" HE-Pex.

 

[Sawyer]

I am trying to calculate head loss on my system. 175” of two 1” HePex lines each for supply and return, starting and terminating at the Garn with a 1 ¼”x1”x1”. And the same fittings at the 5x12x50HX. I added 25’ of length for fittings.

I was not able to find calculators that agree on head loss, perhaps it was due to my unfamiliarity with the programs. I calculated 8-16.6 feet of head using various tables and calculators. Taco’s Taconet 7.0 seemed to give me a good idea of head loss if I am using that program correctly in the absence of a pex pipe and using various pipe categories. It seems the head will be between 10-13 feet and that the pump should be similar to a 0011 if I understand this program correctly.

I am asking if I am doing this correctly. I have read every forum post I could find in a search for head loss but I was incapable of coming up with my own figures I could trust.

Thanks, George

175 feet? One way or round trip?

Basically you can just do a calc for one circuit and double the flow rate if the circ you're using will flow at that level.

BTW, where are you located in Northern Wisconsin? I made a flying trip through there last week on the way to Minneapolis to pick up 1200' of 1-1/2" HE-Pex.

Heaterman, that is 175' one way, the boiler is 175' from the house.

I am in Mercer, just south of Wakefield, MI which is on US Hwy 2 in Western UP. I imagine you went through Iron Mountain and Hwy 8 to MN?

 

[heaterman]

OK. 350' round trip with a pair of 1" lines. I'm going to add some semblance of normal near boiler piping and a set of primary secondary tees that will dump into your house boiler. All 1-1/4", as follows;
40' - 1-1/4" copper tube
10 - 1-1/4" 90* ells
4 - 1-1/4" tees
4 - 1-1/4" x 1" reducer couplings
4 - 1-1/4" ball valves
2 - 350' runs of 1" pex with no additional fittings

The computer crunched out the following numbers

B&G;NRF22- 8.2 GPM
B&G;NRF33- 8.5 GPM
Grundfos 15-58 8.9 GPM
Grundfos 26-64 11.4 GPM
Grundfos 26-99 13.4 GPM
Taco 007 7.8 GPM
Taco 008 8.4 GPM
Taco 0010 8.8 GPM
Taco 0011 12.6 GPM

Note, there is no consideration for the HX but I would think that a 50 plate is going to offer very little flow resistance.

Yep' I Took Hwy 8 down through Armstrong Creek and Laona. What a trip. I don't do 30 hours straight in the truck as well as I used to. We got to a job site Monday morning and proceeded to take the 1-1/2" Uponor out of the box to stretch it out and let it relax prior to laying it in the trench. The excavator was there with the backhoe and my insulation guys were scheduled for Tuesday. I had ordered the pex by actual part number from the distributor I deal with, #1251500. The boys had laid out one of the 300' coils on the ground while I was discussing the job with the excavation guys and Drew came up and says "Dad, you better check out this tube". Long story short the good folks at the distributor had ordered up regular potable water pex not O2 barrier tube. Won't work for a heating application. The way I had the tube and piping arranged precluded the use of a HX to isolate the tube from the house system, ssoooooooooooo ......After a slightly heated phone call it was determined that the only place that had the stuff in stock was right at Uponor in Apple Valley MN.

There I sat with the excavator tearing up the customers yard. the insulating company coming the next day.........sometimes you just take the bull by the horns and do it. Probably a good thing I didn't run into you or anyone else on the trip. I wasn't in a very good mood.

 

[Sawyer]

Thanks for taking the time to run this calculation Heaterman.

I am assuming the calculations came out about 9-10 head judging from the pump suggestions? With the Taco [email protected] GPM the head must really climb? I had a neighbor give me a new B&G;PL36 he had in the shop after I gave him some slab wood from my sawmill. What a nice gift! I noticed that I can place a variable speed but that these are for closed systems, bummer ;-( Maybe I can put it to use in the future.

I am thinking of the Grundfos 15-58 8.9 GPM. First Supply carries them. I sized on SlantFin for 92,000btu/hr@-20*. Considering new construction and Applegate blown cellulose insulation walls and ceilings with all outlets and openings foamed that the under sizing risk is minimal. At 90 watts the consumption should be low. I did have a hard time finding the flow curve on this pump, Grundfos must have it hidden, Taco’s site is easy.

Let me know if you are heading in our direction under “good” circumstances with a little extra time, the musky fishing is good at times.