[an error occurred while processing this directive]
Posted by Heatpro on December 28, 2005 at 22:38:20:
In Reply to: Re: Condensing boiler - Pros & Cons posted by GWR on December 28, 2005 at 21:25:45:
You've asked a very interesting question. Boilers are not rated at 180F water temperature. The DOE AFUE rating procedure gets a seasonal computer estimate at 140F outlet temperature. Lochinvar's IBR BTS 2000 low temp rating is at 110F outlet temperature. The DOE rating shows 91% of the fuel results in heat out of the boiler.
Thus, you can expect 4% more than a boiler rated at 87%. If the home has an average gas heating bill of $200 a month for 8 months, the owner could save $64 a year by buying a boiler for $1500 more. As my heating bill went up to about $1000 this year, I could pay off the extra cost in a quarter century if fuel costs double over that time (hoping that the controls and the boiler last that long and the manufacturer won't change their name, sell out to another company and drop the parts after 7 years.)