December 2009
2 posts
Measuring Efficiency: COP Energy Conversion
It is fairly easy to compare and convert the annual energy costs of oil, gas and electric furnaces and heat pumps. Fuel burning appliance are rated by Btu’s, operating efficiency and the actual fuel costs.
Electrically heated appliances are rated by btu’s and kilowatts and the actual kilowatt costs. The standard for rating electrically powered heat pumps is the Coefficient of Performance (COP)....
Why a modulating furnace may be your best choice...
Most older homes in Seattle were built with belt driven gas or oil furnaces. These old duct systems were sized for relatively low airflow and a relatively high discharge air temperature when compared to current furnaces. Most of these older furnaces had supply air temperatures exceeding 145 degrees. These older duct systems were sized in the pre-air conditioning days and the air returns are...