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Posted by dana on October 06, 2008 at 14:01:12:
In Reply to: new boiler for new home owners posted by Louise on October 04, 2008 at 16:27:19:
: We are newbies with at a 1500 sq. ft. 1930's home and not alot of income. We plan to stay here 20 years and need a new boiler.
: Weil-McLain average type or Buderus fancy high efficiency?
: Also we can opt to go for gas as it's already in the house instead of oil.
: The Buderus is more expensive and we don't know if it's a smart choice.
Gas will likely be cheaper per unit-energy cost in most markets in the US for the forseeable future.
A 1500 square foot house with any reasonable insulation (or even no insulation) isn't going to be an energy-pig. Going with a high-efficiency modulating/condensing boiler may not be the best investment. (If uninsulated, buy the cheaper boiler, spend the difference on insulation.)
Whatever boiler type (except steam boilers, which I presume is not what you're looking at), make sure that all quotes include a Manual-J heat loss analysis, and insist that the selected boiler be no LARGER than the minimum indicated by Manual-J. For a well-insulated 1500' house even most of the small high-efficiency boilers may be somewhat oversized- their lowest modulating-fire being well over the average heat load causing it to cycle.
A cheaper alternative than either a standard or modulating/condensing boiler would be a modulating hot-water heater (which is MORE than enough to heat your house) using a heat-exchanger type indirect HW heater as a buffer tank, as advocated by HeatPro (a frequent poster to this forum):
While cheaper than a standard cast iron boiler, if you use a low-modulating on-demand HW heater (eg: Takagi T-K3, which goes down to ~10kbtuh output at lowest fire), the fact that it give longer but lower fire burns it will be significantly more efficient (especially in a smaller house like yours.) It is less efficient than a condensing unit, but it's a fraction of the cost, and lower-maintenance (indeed, the cost of annual maintenance on a condensing boiler may exceed the fuel savings over the of going with a modulating hot water heater(!).
You may have to shop the concept around to a few heating contractors, but those who understand the fundamentals grasp the sensibility of the approach quickly. Also, due to the high output range at high fire of on-demand hot-water heaters, Manual-J heat loss isn't so essential on a house your size (but do the analysis anyway.) In many respects it's a "one size fits most" heating system design, and a good value in terms of purchased-efficiency-per-dollar.
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