Circulator Pump of Choice?

[boatboy63]

Getting ready to start building a boiler and about to start ordering hardware. Just wanted to know what the circulator pump of choice is that you guys are using. I have seen many different names, but would like to get specific names and model numbers so I will know what has already been "tried and tested". I am looking at about 50-60' each way from my boiler to the forced air heat exchanger in my heat pump. Thanks.

 

[Pat53]

Probably need more info. depends on head, line size, heat load etc.

 

[rkusek]

Good idea to run the numbers. Grundfos 15-58 has 3 speeds and seems to have good reputation from what I can tell. You may want to look into one of the newer variable speed models that adjust based on return temperature. You really need to come up with a piping diagram plan before you buy any pumps.

 

[boatboy63]

Where can I find a chart to run the numbers? My house is approximately 3500 square feet. The 1st floor is about 2000 square feet and is around 120 years old. We have removed vinyl siding and then the masonite underneath it. We then put 4" of fiberglass batt insulation in all wall cavities that were accessable. Next, we put 7/16" OSB over that and then covered with housewrap and vinyl siding. We built the upstairs portion about 10 years ago and it is about 1500 square feet. The walls are all 2x6 with R-19 fiberglass batts. Windows are all thermopane that we replaced during the addition. The ceilings all have about 12" of blown insulation in them, both upper level and what areas of the lower level that were not covered with the addition. The crawlspace is not insulated and is simply dirt. It is hard to do anything with it, as you have about 30" at 1 side of the house and 8" at the back side. I would like to do more with the crawlspace before winter, but am limited due to height restrictions. We did put R-19 in the flooring cavities, but with the age of the lower level, there were no "standards" back then. Floor joists were anywhere from 12" to 26" apart and we tried to keep the insulation in with pieces of wire, but some have fell out.

We currently have a 5 ton heat pump with a 20kw electric strip for backup that supplies all the living areas. I plan to install a 20" x 20" liquid to air hx in plenum to connect the boiler to. I also plan to run 1" pex underground with about 6" of pour foam (similar to spray foam) insulation around the pex. The outside boiler will be about 5' higher than the hx of the heat pump. Also will probably have about 500 gallons of storage, if I have enough money left to do it.

 

[Chris Hoskin]

recommend you spend a lot of time reading the "underground lines" and "Resources for central heating" stickies at the front of this forum.

 

[bigburner]

sounds pretty straight forward. Did I miss something, one boiler & one fan coil. sounds a little boring. Need some under floor, domestic hot water, pool, garage ! but for sure storage or a dump.

 

[juddspaintballs]

If you choose Taco pumps for your application, there is a circulator sizing sheet linked in one of the stickies at the top of this section of the forum. You figure your size heat load, your pipe size, fittings, head, etc. and then it gives you pump curves off of which to size your pump. I'm sure the other major manufacturers have similar charts as well.

Also, from what I hear, you can get a slightly oversized circulator and make it variable speed by using a ceiling fan variable speed controller.