Central Air Conditioner Installation

What a central AC installation includes

A new central air conditioner is two pieces of equipment that have to work as a pair. The outdoor condenser sits on a pad beside the house, and an evaporator coil sits on top of the furnace in the supply plenum. They are joined by a copper line set carrying refrigerant, and the furnace blower moves the air. Air conditioner installation in Hamilton usually takes a day for a replacement, a little longer when a house is getting central air for the first time.

• Removal of the old outdoor unit and coil, with the old refrigerant recovered properly.
• A new pad, outdoor unit and indoor coil matched to the outdoor unit and the furnace.
• A new or flushed line set, and a vacuum pulled before the refrigerant is released.
• Electrical connection through an outdoor disconnect, and a condensate drain from the coil.
• Start-up, with the refrigerant charge set by superheat or subcooling and the airflow checked.

Getting the size right

Air conditioners are sized in tons, where one ton removes 12,000 BTU of heat an hour. A typical Hamilton-area house needs somewhere between 1.5 and 4 tons, and the right answer depends on the floor area, windows, insulation and which way the house faces. An oversized AC drops the temperature quickly, shuts off, and never runs long enough to pull humidity out, so the house feels cool and damp. Ask for a heat-gain calculation. Our furnace and AC size calculator gives a ballpark to compare against.

Efficiency ratings: SEER2

Air conditioner efficiency is now rated as SEER2, a slightly tougher test than the older SEER. Higher numbers mean less electricity for the same cooling. Single-stage units are the cheapest. Two-stage and variable-speed (inverter) units run longer at lower output, which is quieter, more even and much better at dehumidifying in a humid Hamilton July. The indoor coil and furnace blower need to match the outdoor unit to reach the rated efficiency, which is one reason AC and furnace are often replaced together.

Should it be a heat pump instead?

This is the question to ask before you sign. A heat pump is an air conditioner that can also run in reverse, pulling heat from outdoor air in winter. Installed on the same coil with the same line set, it cools exactly as an AC does, and it can take over much of your heating, with the gas furnace kicking in only on the coldest days. Heat pumps qualify for rebates that air conditioners do not. The heat pump vs furnace guide and the heat pumps service page explain when it pays.

Refrigerants and new equipment

Canada’s rules on high-impact refrigerants mean new residential air conditioners and heat pumps are moving from R-410A to lower-impact refrigerants such as R-454B and R-32. These are mildly flammable, so installers follow updated codes and procedures. It does not change anything for the homeowner, but it is a reason not to mix old and new parts: a new outdoor unit needs a matching coil.

Placement and noise

Where the outdoor unit goes matters on narrow city lots and townhouses. It needs clearance for airflow, should not sit under a dryer vent or a deck that drips, and should be far enough from a neighbour’s bedroom window to keep the peace. Some municipalities and condominium corporations have rules on setbacks or placement, so a contractor should check before moving a unit.

Buying, financing or renting

Many contractors offer financing, and some companies rent air conditioners on long contracts. Renting spreads the cost but usually costs much more over the term. Our rent vs buy guide works through an example.

How the request works

You request an AC quote once, and we pass it to one licensed contractor who works your area. They visit, size the house, look at the furnace and ducts, and quote. Ask them to price a heat pump at the same visit. If the furnace is 15 years old or more, ask for a combined furnace and AC quote too.