How big is my boiler and how efficient is it?

[jza29970]

I currently have a 1991 Peerless MCB-130 boiler system. The faceplate says that it has a Max Input Capacity of 130,000 BTU/hr, and a DOE HTG Capacity of 107,000 BTU per houw and a Net I.B.R. Rating of 93,000 BTU/hr.

So what is the efficiency of this system? 107/130 (82%), 93/107 (87%), or 93/130 (72%)? This is important for comparing whether to scrap the old system or upgrade it. (Actually I hate this boiler because it is open flame, has a pilot light, and I can smell combustion products in the boiler room.)

A contractor suggests replacing the system with a Carrier 58MTB100-16 Performance Series Two Stage Furnace, 92% AFUE, 94,000 BTU High out and 61,000 BTU Low out.

Is this proposed system big enough to handle the heating load? I don't want to put in a furnace that is too small. As it is, it takes a long time to heat up and cool down the house. Would I need a different size furnace if I go to a hot air furnace instead of a boiler system?

For what its worth, I currently use about 1500 therms per year to heat the house.

[beenthere]

Its 82% steady state efficient.
Sounds like the guy is recommending the same size furnace as you have boiler.
He probably didn't do a load calc to see what size you need.

Do you have copper fin baseboard, or cast iron rads.

If rads, the hot air system won't make you feel as comfotable as the rads.

Ask him how he determined size.

[jza29970]

Its 82% steady state efficient.
Sounds like the guy is recommending the same size furnace as you have boiler.
He probably didn't do a load calc to see what size you need.

Do you have copper fin baseboard, or cast iron rads.

If rads, the hot air system won't make you feel as comfotable as the rads.

Ask him how he determined size.

Actually, there are no baseboards. The boiler goes to a heat exchanger which pumps forced air through ducts.

[beenthere]

Ok.
The just ask him if he did a load calc.
If he says no he doesn't need to because with his experience with house like your he knows it takes this size system.
Get some more estimates.