Here’s a quick question for you: What is it that makes your home so comfortable? For most people, it’s their HVAC system. In case you didn’t already know, HVAC is short for heating, ventilation, and air conditioning. It’s the home-wide system that keeps indoor temperatures comfortable all year 'round. It generally includes your air conditioning (AC), heat pump, thermostat control, furnace or boiler, air filters, vents and ductwork. It may also include an indoor air quality system, if you happen to have one. Staying cool in summer and warm in winter requires keeping it properly maintained and having all repair issues addressed right away.