What do all those rating numbers mean?
The federal government requires all air conditioning and heating equipment to
be rated for efficiency. The higher the rating, the more efficient the
model.
Gas furnaces are rated for AFUE (Annual Fuel Utilization Efficiency). This
defines the amount of heat recovered from the burned fuel. A 90% furnace will
recover 90% of the available heat and use it to heat your home. 10% of the heat
is vented outdoors. Many older furnaces are only 60% efficient. The other 40% is
vented outdoors. You can see that a new high efficiency furnace will require
much less fuel to heat your home.
For cooling, the rating is SEER (Seasonal Energy Efficiency Ratio). This
rating is based on general design criteria and does not reflect a specific
efficiency level for a specific application. SEER ratings are for comparison
purposes only so that homeowners will know that they can compare different
brands of products with similar efficiency ratings. The rating for the outdoor
unit will reference a general efficiency range, such as 12 SEER. The actual
efficiency rating for a specific system will depend on the combination of the
outdoor unit, the indoor coil, and the size of the system. These ratings are
available to your dealer in the Air-Conditioning and Refrigeration Institute’s
Energy Guide. A variable speed indoor blower unit will increase the efficiency
rating of the system, as well.
Heat Pumps are rated by SEER for cooling efficiency and by HSPF (Heating
Seasonal Performance Factor) for heating efficiency.
All of these ratings can be compared by asking your local independent Trane
dealer, utility provider or referencing the ARI Directory. See our pages of Energy
StarSM Products.
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