Efficient Boiler connundrum

gbwillner

Hello all....

I am currently finishing my basement in my 100+ year old 2-story home. As part of the project, I will be changing the gravity-fed radiant heating system into a in-floor radiant system for the first floor and basement, with a "homerun" set-up for the radiators on the second floor.

I just sold my Weil-McCalin 140,000 BTU boiler, and want to replace it with an energy efficient model. My home heat-loss calculations show a heat loss of 40,000 BTU/Hr. Yes, the previous boiler was overkill, and so were the monthly bills (the boiler temp was never more than 105 degrees- it was set to 170- the house was just already hot before the boiler got anywhere near that).

Anyway, I am looking for a 50K BTU efficient boiler. I have found two models that fit my needs-

Peerless Purefire PF-50 http://www.e-comfortusa.com/products...as-boiler/2084
and
Peerless PI-N50-N http://www.alpinehomeair.com/viewpro...ctID=453061902

I'm sure there are other brands out there. Anyway, these two units are similarly priced, but other than the fact one has a 3" vent and the other a 2" vent, I really can't tell what the difference is.

Any help is apppreciated.

Thanks!!!!

beenthere

I think Peerless makes the PF. but the PI is a Munchkin in disguise, its made by HTC.

gbwillner

Is that good or bad????

THanks!

beenthere

Do a search on Munchkin boilers. You decide if its good or bad.

gbwillner

Interesting.... I found tons of horror stories about the Munchkin model (T80M) having some F09 error code... but nothing from the peerless one... And they do look errily similar.. and by that I mean exactly the same.

Oddly, I can't find more than one retailer selling that Munchkin model (but lots selling the Peerless one).

My only real interest in this model is the 2" venting. It would make things a lot easier for me during the install.

Home Air Direct

I would guess that 90% of all boilers put into service years ago were way oversized, and most boiler replacements are just that. Replacements of the same oversized boiler.

Your WM 140 boiler was probably 80% efficient as have most boilers been the last few decades. The condensing boilers will be near 15% more efficient out of the box, but the real savings comes when a properly sized boiler with modulation features comes into play. When your 40K load is only asking for 20K, the modulating boiler will react and only fire at a rate needed for the load. We see 40-50% reductions of gas bills when this match is met.

I have no experience with the Peerless, beyond ordering peerless parts for customers. It looks like a nice unit. I would however, consider the 80K btu unit. I know that flies in the face of oversizing, but at 50K, you are maxed out of your need. And, though you do not want to oversize, you do need a "fudge factor".

We sell the Weil-McLain Ultra-3 boilers and have had nothing but rave reviews from our contractors.

Good luck to you.

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gbwillner

Thanks for your help. I figured the heat loss for the coldest day (averaged) in the past five years (Saint Louis).

Do you still think I should step it up to a larger size? The cost from a 50K to an 80K is not that significant.

bob22

I would use historical records, not last 5 years:
http://www.wunderground.com/NORMS/Di...=on&records=on

MIght also google degree days for St. Louis.