Gas and oil boilers provide warm, even heat throughout your home by circulating steam or heated water through a system of pipes and baseboard or radiator-type heat exchangers.
Boilers provide warm, even comfort without drafts because it's not a forced
air system. Instead, warmth "radiates" throughout your home
without causing much of the dryness associated with heat from a forced-air
system (furnace or heat pump).
A boiler's efficiency rating, or AFUE (Annual Fuel Utilization Efficiency)
tells you how efficiently the boiler uses fuel (gas or oil). The government-mandated
minimum efficiency for boilers is 78% AFUE. Higher efficiency boilers
are rated as high as 95% AFUE.
- How They Work
- Energy Efficiency
How They Work
The heat is created by burning gas or oil. Hot gases
that are created pass through a cast iron or aluminum (in 95% efficiency boilers) heat exchanger. The hot water or steam, travels through pipes to radiators or convectors to heat your home.
Purchasing a brand name that has a reputation for quality and reliability
can save you headaches and extra expense down the road.
New Weil-McLain or Lochinvar furnaces, for example, undergo a rigorous series of quality
tests and checks, during production, with many of the tests being performed
on every unit - not just random samples.
Warranties vary by product, from a lifetime warranty on cast iron to a 15-year limited warranty
on the heat exchanger (the heart of the furnace) and a one-year limited
warranty on the entire unit. Extended warranties are also available.
Some mid- and high-efficiency furnaces offer additional features that
provide greater comfort, as well as additional energy savings.
Modulating/Condensing, gas-fired boilers (ModCons), improve performance, comfort and efficiency. These boilers offer a burner that varies its heat depending on how much heat the house needs, turning the burner up or down as needs change.
Variable-capacity furnaces provide the ultimate combination of comfort,
efficiency and quiet performance. In addition to the benefits of two-speed
furnaces, they offer "smart" motors than can monitor your homes
comfort needs and automatically adjust the volume and speed of air to
provide the most efficient heating or cooling. They offer added electrical
efficiency as well: the "smart" fan motors on Carriers
variable-capacity furnaces use less electricity than a 100-watt light
bulb. They operate so efficiently that they can actually increase the
efficiency rating of your central air conditioning system and offer you
added energy savings when you use continuous fan operation in any season.
A furnaces efficiency rating, or AFUE (Annual Fuel Utilization
Efficiency), tells you how efficiently the furnace uses fuel (gas or oil).
In general, higher efficiency furnaces mean lower monthly operating costs
The government-mandated minimum AFUE rating for furnaces installed in
new homes is 78%. In contrast, many furnaces manufactured before 1992
had AFUE ratings as low as 60%.
Higher efficiency furnaces offering AFUE ratings of 80%, 90%, or up to
96% are also available to help reduce monthly heating costs.
Usually, the higher the efficiency, the more expensive the initial cost
of the furnace. If you live in a cold climate, you will probably see the
higher cost of a high-efficiency furnace paid back through lower utility
bills in a few short years. Your dealer can use heating data from your
area to help you determine about how long it would take you to recover
the additional cost in energy savings. Of course, after the payback, you
continue to save on your energy bills for the life of the system.