When an air conditioner reaches the end of its life in Tucson, the replacement conversation usually starts with a brand name. It should start with the type of system, because that decision has more to do with your house than with any logo on the cabinet. Most homes here are served by one of three configurations, and each has a place.
Split systems
A split system is what most people picture: an outdoor condenser on a pad beside the house, an indoor air handler or furnace in a closet, garage or attic, and refrigerant lines running between them. Air conditioning happens outside; the indoor unit moves the air.
Split systems are the most common choice for newer homes with a dedicated mechanical closet or an air handler in the attic. Because the two halves are separate, you can often replace one without the other, though mixing an old indoor unit with a new outdoor unit usually costs efficiency and can void the warranty. When we replace a split system, we match the indoor and outdoor units to each other and to the home's load.
Rooftop package units
Drive through any older Tucson neighborhood and you will see them: a single cabinet on the roof that holds the compressor, coils and blower together. Package units are common on the flat-roofed block and slab homes that make up so much of Tucson, because there is no attic or closet to put an air handler in.
The advantages are practical. Everything is in one place, there are no refrigerant lines running through the house, and installation on an existing roof curb is straightforward. The trade-offs are that the unit lives in direct sun all day, which is hard on electrical components, and that duct connections on the roof need to be sealed well or you end up cooling the sky. A package unit that is properly sized, installed on a sound curb and sealed to the ductwork is a reliable system for decades.
Heat pumps
A heat pump is not a third piece of equipment so much as a capability. Both split systems and package units come in heat pump versions. In cooling mode a heat pump works exactly like an air conditioner. In winter it runs in reverse, pulling heat from the outdoor air and moving it inside.
Tucson winters are exactly the conditions heat pumps are built for. Nights dip into the 30s and 40s, days recover into the 60s, and a heat pump can carry that load without the electric strip heat that makes them expensive to run in colder climates. For a home without natural gas, a heat pump is nearly always the better choice over electric resistance heat. For a home that already has a gas furnace, the choice comes down to gas prices, the age of the furnace and how much heating you actually do.
Ductless mini-splits
Worth mentioning because we install them often: a ductless mini-split pairs a small outdoor unit with one or more wall-mounted indoor heads. They are the right answer for a casita, a garage conversion, a room addition or a home office that the main system never reaches. They are not usually the right answer for replacing a whole-house system in a home that already has ductwork.
How we decide
The equipment type is only part of the decision. Here is what actually determines whether a new system performs the way the brochure promised.
- Sizing. Bigger is not better. An oversized system cools the air quickly, shuts off before it dehumidifies, and cycles constantly. We calculate the load from the house, not from the size of the old unit, which was often oversized to begin with.
- Efficiency rating. Efficiency standards are stricter in the Southwest than in most of the country because we run cooling for more hours. The gap between a minimum-efficiency unit and a higher-efficiency one shows up on every summer electric bill for the next 15 years.
- Ductwork. A new system attached to leaky, undersized ducts will not deliver its rated capacity. We look at the ducts before we recommend equipment, and sometimes the right first step is duct repair, not replacement.
- Electrical. Older homes may need a panel or circuit upgrade for a modern system. We check this during the estimate, not on installation day.
What to ask any contractor
Whoever you hire, ask how they sized the system, whether the indoor and outdoor units are a matched pair, what the efficiency rating is, and how they plan to test and seal the duct connections. Ask to see their Arizona ROC license too. A clear answer to those four questions tells you more than any brand comparison.
We provide free replacement estimates with transparent pricing and no pressure, and financing options that do not affect your credit score to check. Request an estimate or call (520) 261-3909.