Posted by Guy on September 07, 2001 at 07:53:46:
In Reply to: Re: Payback for an Indirect Water Heater posted by Harold Kestenholz - Hydronic Network on July 19, 2001 at 11:57:05:
: : For a stand alone water heater the cost of gas for a year is approx $200.
: : Let's assume that the indirect uses half the amount of gas - $100, thereby saving $100 year.
: *** The indirect will not use half the gas of a water heater - maybe 85% due to the better iinsulation and no stack loss. The importance of the indirect is its longevity - a stainless unit like the Triangle-Gold will not need replacement. A water heater in a hard water area will need replacement in five years. So figure 3 or 4 separate water heaters in the cost figures over 20 years.
: There will maintenance for two burners - only one burner for the indirect.
: : I realize the indirect will provide better heat recovery. Perhaps a 30 gal indirect is more comparable to the 40 gal stand alone.
: Also what about the fact that you run the boiler in the summer for short bursts to heat the indirect. Is this more harmful than helpful?
: However, you might consider during the summer that the water heater will be sitting there giving heat off all summer AND WINTER. The indirect will have water sitting in higher insulation all year with no flue loss. A burner run will be more than 5 minutes to refresh the indirect tank 20 degrees, so this is not a rapid-on-off damaging short cycle.