Circulator sizing on Superstor 50 Gallon?

cwilliams2000

Just trying to replace a failing circ pump and they had a 3 speed Taco installed but at the time they did that since that was what they had. This tank is on a normal residential boiler and only maybe 6 feet away. Just wondering would I go with a less hp like a 1/35 taco. I just replaced my main circ with a VT2218 but for the extra money I dont think this would do much since it only runs a minimal amount of time. Just not sure if I need an 007 or maybe thats bad and too powerful? Thank you

Paul S_3

I think 005 is too small. ...in the manual it says for the ss-45 coil has 8 ft of head and need a flow of 10gpm...whats the model # of indirect

SWEI

What size and type of boiler is it?

cwilliams2000

Hi its a Peerless WBV-04, I think its around 80k with burner setup. The piping is 1"

SWEI

A WBV-03 fired at 84k has a DOE output of 75k, so figure 7.5 GPM at a 20°F ΔT. SSU50 shows 6.48' of head at 8 GPM for 20' of pipe with elbows and HX. A 005 would be darned near perfect there.

mikeapolis

Install a Grundfos Alpha.

hot_rod

mikeapolis said:

Install a Grundfos Alpha.

Good call on the Alpha, it will use about 1/2 the electricity as the non ECM circs mentioned above, and give you plenty of flow.

Solid_Fuel_Man

The Alpha is a great circ, but on an indirect with its own dedicated circ, there will never be enough runtime to come close to paying for the upcost. Standard (and inexpensive) 007 gets my vote.

SFM

CMadatMe

Could I please ask the question nobody has... What is your DHW need? From there, then we should size properly. Too many carts before the horse.. Based on the thread I'm going to assume the heating system is zoned circ's but you haven't really told us that either. @Hatterasguy is spot on with the 1" piping and more then likely correct on the 007 but the initial question I asked should be answered. A 005 is priced more then an Alpha, so scrap that idea.

CMadatMe

Hatterasguy said:

Chris said:

Could I please ask the question nobody has... What is your DHW need? From there, then we should size properly. Too many carts before the horse.. Based on the thread I'm going to assume the heating system is zoned circ's but you haven't really told us that either. @Hatterasguy is spot on with the 1" piping and more then likely correct on the 007 but the initial question I asked should be answered. A 005 is priced more then an Alpha, so scrap that idea.

I take the position that you cannot overpump an indirect with the exception of the electric cost.

If the 007 is satisfactory, the price surely dictates its procurement.

You can pump a bit faster with a much more expensive pump, but the gain isn't worth the cost.

Didn't know anyone was arguing another position. It's a loaded position anyway. We both know a 007 will get the job done on a cast iron boiler application. My car will also operate with 15 PSI in all the tires too.

bmwpowere36m3

50 gal megastore, 3/4" piping 10' or so and 55k BTU boiler... I run the Grundfos 15-58 that came with the boiler on speed II, delta T 5-7*

SWEI

Some of the northeast states have rebates that make an ECM circ net out under $100. Lacking that, the runtime on a conventional PSC wet rotor circ in a residential DHW app is not enough to make the efficiency increase worth worrying over.

Chris brings up a good point about the 005 pricing. 007's are common as dirt.

ced48

As far as oversizing a pump for an indirect, it is false to say that you can not over pump. Choosing a pump which is grossly oversized, can, and will cause turbulence, and air issues.

Also, from past experience, the Superstor heat exchanger's have far less flow resistance than their posted numbers.

Rich_49

Chris , the disagree was based on the fact that this poster is trying only to replace a failing circ , not sizing a system .