Many homes are equipped with heat pumps as their heating and cooling system. Heat pumps work well at most temperatures; however, under extreme temperatures, they may not provide the expected level of comfort. The following are some operating and maintenance tips to help you set realistic expectations for heat pumps and to maintain the system with maximum energy efficiency and operational efficiency.
Heat pumps absorb heat from one place and transfer it to another. In air conditioning mode, they absorb heat from inside and transfer it from outside. In heating mode, they absorb heat from the outside and transfer it in. This process works when the outdoor temperature is between approx. 40 and 95 degrees F. It is more difficult for the system to maintain comfortable indoor temperatures when the outdoor temperature is outside this range. Older systems and systems that are poorly maintained may have a narrower temperature range outside, within which they can maintain comfortable indoor temperatures.
Heat pumps, like any heating and cooling system, must be the right size for the home. A common misconception about heat pumps is that a larger system is always better; in fact too big is bad. A heat pump that is too large may not run long enough in air conditioning mode to effectively remove moisture from the air. This can create moisture regulation problems that can contribute to mold growth. A heat pump is less energy efficient when it starts running and does not reach full energy efficiency for several minutes. A heat pump that runs for short periods costs more to run and can have a shorter service life.
Heat pumps are less efficient in cold weather. Therefore, they are less common in northern areas. When the outdoor temperature drops below approx. 40 degrees F. a heat pump may not be able to raise the internal temperature to a comfortable level. Heat pumps in cooler climates are equipped with auxiliary heating elements. These elements look and function much like the wires that glow red in a toaster. Like their cousins in a toaster, these items provide extra warmth to help bring the indoor temperature to a normal level. Because it is difficult to know if these items are working properly, get them tested as part of normal system maintenance.
A heat pump must maintain a comfortable indoor temperature. The International Residential Code (IRC) heating performance standard requires that the system maintain a home temperature of at least 68 degrees F. IRC has no performance standard for cooling. The National Association of Home Builders (NAHB) heating performance standard is 70 degrees F. and the cooling standard is 78 degrees F. or 15 degrees C. below an outdoor temperature of 95 degrees F. States and cities may have different standards. The performance temperature is often measured near the center of the room and approx. 5 meters above the floor.
The IRC and NAHB standards are not clear on temperature deviations between areas in the home, but it is reasonable to expect that the temperature in each area is close to the temperature at the thermostat. Some temperature variations between areas are normal and unavoidable. It is reasonable to allow one or two degrees of temperature variation between areas.
Operating a heat pump is equivalent to operating any forced air HVAC system. In most cases, the recommended thermostat settings for heat pumps are 68 degrees F. in winter and 78 in summer. These settings provide energy-efficient operation at reasonable comfort levels.
The use of recoil thermostats is generally not recommended for heat pumps, especially not in heat mode. Heat pumps are often designed so that in heating mode, if there is a difference of approx. 3 or more degrees between the thermostat setting and the internal air temperature, the auxiliary heating elements are activated. The heating elements are much more expensive to run than the heat pump itself, so the use of the heating strips should be avoided.
Maintenance of heat pump starts with regular replacement of filter. If you choose disposable filters, use the cheap blue or white mesh of the fiberglass mesh. The more expensive folded paper filters can restrict the airflow in the system, making it work longer. Change these filters every month.
0 Comments