Our Indianapolis climate is known for hot, humid summers and snowy, cold winters. Spring and fall usually zigzag between the extremes. Like everywhere else, we can expect a climate impact on the kind of HVAC equipment we install.

To deal with the extremes of cold, heat and humidity, we need to make some well-considered choices for HVAC installations. Here are some things to think about as they relate to climate impact and your HVAC system.

Efficiency rating.

Air conditioners, heat pumps, and furnaces are rated for their efficiency: SEER (AC), HSPF (heat pump) and AFUE (furnace) are the terms used for those ratings. Generally, the higher the rating, the more efficient the equipment. Federal regulations mandate particular efficiencies according to regions. In our northern region, we can sell a slightly less-efficient AC than is sold in the southern region due to our somewhat shorter cooling periods and lower average summer temperatures.

If your home tends to be cold, you may need a more efficient furnace — one that reaches AFUE 90 — to reduce energy costs due to the climate impact of low temperatures. Likewise, if your home tends to be excessively warm, you may need a more efficient AC or heat pump to reduce the energy costs of the climate impact of high summer temperatures.


For your equipment to achieve a high AFUE or SEER, the home should be well insulated, and minute cracks around windows, doors, and baseboards should be sealed with caulk. Also, have ductwork inspected and repaired so that conditioned air doesn’t escape and so that unconditioned or humid air doesn’t intrude. Otherwise, your HVAC system will be working too hard to achieve set temperature points.


An HVAC system in a humid climate needs to be able to maintain positive pressure with dehumidified air inside the home’s envelope, or mold can result. In general, this is not a problem in our region unless the home presents excessively humid conditions. If so, it may be necessary to use dehumidificationequipment.

For more on climate’s impact on an HVAC system, contact Mowery Heating, Cooling and Plumbing.