Using a Programmable Thermostat With a Heat Pump

Heat pumps and programmable thermostats have become popular these days as people try to find ways to reduce their energy consumption.  Whether motived by decreasing their carbon footprint, lowering their energy bills, or both, heat pumps and programmable thermostats are excellent alternatives for lowering the amount of energy used to heat and cool homes.

However, if you are not careful when using a programmable thermostat with your new heat pump you may end up wasting energy by activating the auxiliary heat too often.  A heat pump is an energy efficient way to heat a home because it moves heat rather than creates heat.  As the name implies, a heat pump moves heat from outside the home to the inside to warm the home.

It is an efficient and economical system, but it is less effective at temperatures below freezing.  To compensate for this, most heat pumps have auxiliary electric heating strips installed to supplement the heat when the heat pump can’t keep up with the demand for heat.  Heat strips are an expensive way to heat, but if they are used sparingly a heat pump is still an efficient heating system.

The problem with programmable thermostats is that they are typically set to lower the temperature about 10 degrees at night and when the homeowner is away during the day.  When the program switches back to the more comfortable higher temperature setting, the heat pump tries to reach that temperature quickly and the electric auxiliary strips are activated.  Using the electric auxiliary heating strips to bring the temperature backup offsets the energy savings from lowering the temperature during the night and might even be counter productive.

If you use a programmable thermostat with a heat pump, program it so the temperature only drops two or three degrees at night to avoid activating the auxiliary heating strips.

Choosing a Programmable Thermostat For Your Heat Pump

A programmable thermostat is an excellent energy saving piece of equipment.  According to EPA estimates, by automatically adjusting the temperature of your home to match your work and sleep schedule, a programmable thermostat can save up to $180 per year in energy costs.

In the winter, a programmable thermostat lowers the temperature setting while you are sleeping or at work, and automatically raises the temperature so that your home is comfortable when you wake up or get home from work.  It works the opposite in the summer.

If you have a standard gas or oil furnace, most universal programmable thermostats will work fine.  Your HVAC technician can install one for you or you can choose one of the many programmable thermostats available at your local home improvement center if you are the do-it-yourself type.

If you have a heat pump, you should talk to a reputable HVAC contractor who has heat pump experience and carries HVAC accessories and optional components.  Until recently, most programmable thermostats worked fine when the heat pump was used in cooling mode, but they were not very effective at saving energy for heat pumps in heating mode.

When the temperature setting is increased more than a couple degrees, most heat pumps rely on auxiliary electric heating strips to help bring the temperature up to the desired setting.  Using the auxiliary heat cancels out the energy savings from lowering the temperature at night.

There are now some thermostats specifically designed to work with heat pumps.  Your HVAC professional can help you choose the right thermostat for your heat pump and make sure it is installed and set up to work properly with your equipment.