Heat pumps have become more popular installs in the Midwest and are ideal for homes or buildings where natural gas is not present. They can also contribute to a carbon free home design. Heat pumps use the A/C condenser, this means in both the summer and winter the A/C needs maintenance and monitoring. Older model heat pumps generally do not operate below temps of 32 degrees and rely on a back up source such as natural gas, but most commonly electric strip heat (think toaster coils).