Year-Round Cooling and Heating
QUESTION: I should replace my noisy, inefficient heating and air-conditioning system. Will a ground-source heat pump really provide $3 of free heat for each $1 on my utility bills? How comfortable is it year-round?
ANSWER: A ground-source heat pump is an extremely efficient year-round system. It can save the typical family more than $10,000 on utility bills, compared to installing a standard system. If you have an old gas furnace, it may make economic sense to add a pump.
For each $1 on your monthly utility bills, a ground-source heat pump draws an additional $3 of free heat from the earth. In effect, it uses your yard as a giant solar collector to provide heat for your home in the winter.
The heating comfort with such a pump is excellent. The “chilly” feeling, common with ordinary heat pumps, is eliminated. Cooling output is strong and steady. For the greatest comfort and improved air quality (for allergy sufferers), choose one of several new two- or three-output level models. These constantly fine-tune the heating and cooling output to the need of your house.
In the summer, a ground-source heat pump switches to a super-efficient central air-conditioner. As it is cooling your home, it heats your water--free. With an optional heat exchanger, it can heat your water four times more efficiently in the winter too.
This type of pump recycles the heat energy in your home. In the winter, it draws heat out of the ground, making it cooler. In the summer, it reverses and exhausts the heat to the cool ground for use next winter.
Most work by circulating a water/antifreeze solution through small plastic pipes buried in the ground. Since the ground is warmer than the outdoor air in the winter and cooler in the summer, efficiency is high.
One of the most efficient designs, called a DX system, circulates the refrigerant in small copper tubes in the ground. This requires less piping and eliminates the need for an extra heat exchanger and circulating pump.
These pumps are very reliable. The entire unit is located indoors (no noisy outdoor condenser fan is needed), so it is protected from the weather. It is a very simple device with few moving parts to wear out.
Some use two-speed compressors to provide two output levels. Other models use two separate small compressors (just one or both run). For ultimate comfort and efficiency, three-level models use one small and one medium-size compressor. Run the small, the medium or both.
Write for Update Bulletin No. 614 showing a buyer’s guide of 13 single-, two- or three-level pumps listing heating/cooling outputs, efficiencies, compressor type, blower speeds, features, prices, operating cost comparison chart and ground loop layouts. Please send $2 and a business-size self-addressed, stamped envelope to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.
Letters and questions to Dulley, a Cincinnati-based engineering consultant, may be sent to James Dulley, Los Angeles Times, 6906 Royalgreen Drive, Cincinnati, OH 45244.