In a Heat Pump packaged system, all equipment is built into an outdoor unit, usually set on a pad or concrete slab. The "package" that gives it its name provides central air conditioning during the summer and heat in colder months. Contrast with "split system".

Also referred to as (Packaged Unit). A piece of air conditioning and heating equipment where all components are located in one cabinet, typically installed outside a house or building on a pad or slab.

A type of air conditioning and heating system that is contained in one outdoor unit. Package Units can be installed beside or on the roof of homes and buildings. Also see "self-contained system". Contrast with "split system".

Overall measure of the efficiency and value of your home comfort system. By combining your purchase price and ongoing operating costs, a payback analysis determines the number of years required before monthly energy savings offset the purchase price.

Preventive Maintenance Agreement -- these are agreements offered by HVAC contractors that set a certain number of maintenance visits per year, usually for a discounted fee. They are known by a variety of phrases, such as "maintenance inspection agreements", "planned service agreements" and so on.

A programmable thermostat helps make it easy for you to save by offering pre-programmed settings to regulate your home's temperature in both summer and winter - when you are home, asleep, or away. This is one of the least expensive improvements for increasing comfort and saving on monthly heating and cooling bills.