Is the performance of your heat pump lower than expected? Check out why and how to improve it.
There are many reasons why your heat pump doesn’t perform well, and we will mention some of the problems that can occur often and be easily fixed. According to some experts, either you own an old or new Energy Star heat pump the performance might not be as expected.
The reasons for lower heat pump efficiency are various from the incorrect unit size and installation to an insufficient air flow and refrigerant, location of the unit or just failing components. In order to avoid potential problems that can affect the performance of a heat pump, efficiency and your comfort, check out the recommendations below:
Try to insulate your home as much as you can. This includes the moisture barrier, insulation with a high R value (recommendation is R-30 for ceilings and R-11 for exterior walls, or higher), sealing the gaps and installing energy efficient doors and windows. By making the home energy efficient, the unit size can be smaller and ducts shorter. A well-insulated house keeps the heat or cold air longer inside while reducing the heating and cooling costs.
It is recommended to install the unit on the north side of a house or in the shade and away from objects that can affect its performance (big trees, shrubs, and other plants…)
Even if you have the best model with the high energy efficiency, poor installation and service can lead to poor performance of the heat pumps, premature failure and expensive repairs. It starts with the proper sizing where heating and cooling loads are accurately determined and the amount of air flow and duct size correctly calculated, with no obstructions. Seals are leakproof and system is hooked up per codes and manufacturer recommendations. And this is not all, the regular maintenance will keep the performance as expected and the unit will last for a long time.
Keep in mind that the refrigerant charge should be done by a professional. Too many things are involved; proper tools, high refrigerant pressure, potential risk…
Charging a heat pump is similar to charging AC – in summer and cooling mode, but it is different when the temperatures are lower. And different methods are used; by weight, discharge temperature method, or simply follow this link to the detail explanation.
In order to keep the performance of your heat pump up, regular and proper maintenance is a must. This includes cleaning the coils on both evaporator and condenser from debris, snow and ice, maintain proper clearance, and remove any obstructions in the drain openings, inspecting fans…
It would be ideal if there is no air duct leakage, but in reality this is significant. According to some studies it says that an average 20% goes on energy waste in ducts, and it depends on the location of the ducts. Try to keep the air leakage between 5 and 10 percent of the heat pump system airflow. The material of the ducts must be according to the best practice and manufacturer recommendation, secured and sealed using the proper compounds. Avoid duct materials and building cavities used as ducts as it produces a lot of leakage. Once the duct system is in place, or you are suspicious about the existing one, arrange the testing to make sure everything works properly.
According to the experts, between 400 and 500 cubic feet per minute of airflow should be provided for each ton of the heat pump AC capacity. If it is less than that, the performance is decreasing so as the comfort. The solution is to make the ducts bigger or if possible, increase the speed of the fans.
Every room should have one of more registers for the air intake and supply, so the correct air circulation is provided. There should be no blockage. If for any reason some rooms do not have registers, a connection between the rooms should be provided by installing the louvered grilles on doors or windows. The capacity of the heat pump is in direct correlation with the airflow.
Choose a 7-day programmable thermostat and let it control the indoor climate for the maximum efficiency. It allows you to program several different temperatures on a daily basis either for cooling in summer or heating in winter, or maintain set temperature when away for vacation. The recommended indoor temperatures are around 68 F for heating, 78 F for cooling and lower/higher when on vacation, but this is relative. Turn the fan to AUTO mode, or switched to ON, which increases the energy consumption, but at least the temperature distribution inside the house is even, no hot or cold pockets. This is what helps removing the moisture from the house out. Otherwise there would be more stress on the compressor.
Keep in mind that your heat pump unit is a sophisticate electric device which, in order to avoid the warranty issues, should be maintained and serviced by a professional and licensed technician.