If your pump is cycling 19 times an hour, then it is obviously a larger pump than it needs to be for the heat pump. Changing to a smaller pump that will run continuously at the flow required will reduce the electric bill a little. However, this could leave you out of water when the heat pump is running and you require water in the house at the same time. You probably need the size of pump you have to use for the dual purposes of heat pump and house. Cycling the pump 19 times per hour is the real problem. Cycling destroys the pump system. Replacing the pump system often can be so expensive that saving a little energy will become low on the list of priorities. A Cycle Stop Valve in this situation may not save you any energy because, even though your pump is cycling now, it is still running at about it’s most efficient point. A Cycle Stop Valve will push the pump out of it’s most efficient point by a little bit but, it will probably make that up by eliminating 19 starting spikes per hour. What the Cycle Stop Valve will do however, is triple or quadruple the life of the pump system by eliminating all that cycling. Instead of buying a new 1 HP pump every two or three years, eliminating the cycling will make one pump last 8 to 10 years or more. Making your pump system last can quickly become more important than saving an extra $20.00 per month on the electric bill.
Even if the heat pump could save $250.00 per year, if your $1,000.00 pump will only last 4 years then you are not saving energy or money.. If you are really looking at energy savings alone, you may have to look back further. If saving a little energy means replacing a pump every 5 years instead of it lasting 20 years, then how much energy is used to manufacture, transport, install, and dispose of those extra pumps and motors. A big part of what you pay for the extra equipment, is used for energy. It is like the hybrid cars. If you have to replace the batteries every 35,000 miles, the money you save on gas is spent on batteries. The cost of batteries includes the energy to mine, manufacture, and transport new batteries as well as everything that is involved in disposing of the old batteries. Making equipment last, is the best way to save money and energy.
You could us a ½ HP well pump that is throttled back very little with a valve to match the requirements of the heat pump. Running at 20 PSI instead of 50 PSI this ½ HP pump would use less than half the energy you are using on the heat pump now. Before the heat exchanger you can tee to a ½ or 3/4 HP jet pump with a CSV and a small bladder tank to feed 40/60 PSI pressure to the house. When the house needs water and the jet pump starts, the back pressure on the well pump decreases and the well pump begins to supply more water feeding the heat pump and the jet pump for the house at the same time. The jet pump will pick up water at 20 PSI and deliver the GPM needed for the house at a constant 50 PSI. When the house is no longer using water, the small pressure tank fills to 60 PSI and the jet pump is shut off. Then the back pressure on the well pump will increase, reducing the output of the well pump to supply the heat pump alone. In this way you are only running a ½ HP pump instead of a 1 HP pump for the heat pump. Then another ½ or 3/4 HP pump comes on only when needed to boost the flow and pressure to the house. With a Cycle Stop Valve on both pumps, they will last a long time so this $40.00 per month energy savings from the heat pump will really be a bonus.
