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[Kelch1]

Wondering if anyone has a good estimate on head loss numbers for a 16x22 140,000 BTU water to air heat exchanger and a 48" copper sidearm water heater.  I am trying to narrow down my pump search, but I did not know how to factor in my heat exchangers for my head calculations.  I came up with 357 equivalent pipe length, and 15.2 ft. of head, but did not factor in my heat exchangers yet.  My system is 112' of 1-1/4" Rehau underground to stove, and all one inch copper in the house with long radius  90's used throughout.  Also, does anyone know approximately how to figure out the BTU's used by a standard copper 48" sidearm? Having a heck of a time finding that info.     Any help would be appreciated.

[RSI]

At 5gpm 0.8' of head
at 10 GPM 2.8' of head
at 12 GPM 3.9' of head.
See PDF attachment for more specs.

The sidearm will vary depending on sizes. I wouldn't think it would be much more than a couple elbows.

[Kelch1]

Hey RSI, your Johhny on the Spot!  Thank you for the PDF, good info.  I guess the BTU's of this think are not as high as I was hoping.  Just was going off of what the place I bought it from told me over the phone.  Not sure what my GPM's are yet, as I have not been able to figure that part out yet.  I estimated the btu's required by using the output of the current forced air fuel oil furnace.  Tried to make my system as free flowing as I could after hours of reading how guys wish they had done it on this site.  I just want to get this thing running, hate to admit it, but it has been sitting on the slap for 13 months, and hasn't burned a stick of wood yet! Do you still sell those kits for the blower fan shut off with a aquastat to keep them from running if the fire goes out?  Still think I'd like to put one of those on.  Thanks again for the quick response!
 

[RSI]

It looks like the BTU number is wrong for the bottom row since it shouldn't be lower BTU at 10 GPM than it is at 12.

Most companies advertise 50K btu per sq ft of coil and some have been doing 60K. As you can see from the chart, all they are doing is pumping more air and water through them to get higher numbers or using a different number than 65 degrees air temp.

[mlappin]

Usually if you have all the rest of your calculations done correctly and if your borderline on possibly needing the next pump up, just figure on the next size up if the head numbers aren’t available for the HX and sidearm.


Its pretty easy to get the proper size pump anymore since so many offer a three speed pump.

[Kelch1]

Thanks for the suggestion,  I purchased a Grundfos 15-58 super brute three speed pump.  It was close to the requirements I think I need, and available in stock locally.  It met the gpm and head pressure ratings I think I need.  Time will tell.............  Thanks for the feedback guys.  RSI ..  Still selling those kits for the blower fan shut off?

[RSI]

Yes, I had another batch of those controllers made up.
What did you have to pay for that pump? It looks like it should be a good size.

I swapped my Grundfos 15-58 pump out for an Armstrong 20-20CI about a month ago because it uses only half the power.

[mlappin]

Hows the reliability of the Armstrong pumps? I have a Grundfos still in use I installed in 2001…..

Of course in this day and age of make it cheaper, sell it for more, the new Grudfos pumps may not last as long as the old ones….

Just wondering is all, I’d have to change out a lot of pumps in my system to ever notice any difference on our electric bill especially in the winter between plugging in tractors, trucks and the livestock waterer heaters.

[RSI]

Since they just started making the ECM pumps recently it is hard to say. I like them better than the Grundfos ECM pumps so far. (I have one of each on my G200)

One of the 15-58 pumps I took off was from this year and the other I put in about 10 years ago. The old one wasn't quite as quiet but still working.

[mlappin]

So exactly who is Armstrong? I figured it was a cheap chinese knockoff, but after a little research sounds like the company might have been around for awhile and just got into residential circulators.

[RSI]

They are an american company based in New York. They have been making residential circulators for years but have a small market share compared to Grundfos and Taco.

[Kelch1]

RSI........I paid $98 at Menard for that pump two days ago.  They also had a Taco 007, but I liked the three speed option better.  Not sure how my system will perform yet, so I liked having the adjustability of the three speed.  They had some off brands with similar specs " hydrasmart" .  But they used even more juice at similar head and flow settings.  Thought I better stick with a brand I've heard of.  No Armstrong on their shelf.  Really liked what I've read about Taco "Bumblebee "  and the Grundfos alphas, but I assumed those were more for zoned systems, not single continuous loop.  More money too, but heck with what I've got into this install.......what's another hundred bucks!  15-58 was the best option on the shelf, would have had to order anything else.  If I don't get this thing runnig soon, the Wife will probably put my stove on Craigslist! 

[RSI]

That is a decent price for the 15-58. I thought Menards got more than that for them. The 007 would not have been a good option. The other pumps they sell are Chinese knockoffs.

The Alpha pump has fixed speed settings that use half the power of a standard equivalent pump. There is just more power savings on a zoned system but work on any.

[Kelch1]

Yeah, I did alright on the Grundfos.  They had their "save 15% on anything you can fit in their Brown Paper Bag" sale going on!  Every little bit helps.  Thanks you for the responses, hopefully I'll know how the pump performs on Friday.  Little nervous about doing the initial fire up in this weather, had -17 below this AM.  Friday still looks awfully cold, if something doesn't work right, I may be in a heap of trouble!!