Overview
Installing central air conditioning, or replacing a system that has reached the end of its life, is one of the larger home equipment decisions most people make. A split system has an outdoor condenser and an indoor evaporator coil, usually sitting on top of a furnace or air handler, connected by refrigerant lines. The equipment itself matters, but the quality of the installation, including sizing, refrigerant charge, airflow and duct condition, has a large effect on comfort, efficiency and lifespan.
Homes without existing ductwork have other options. Ductless mini-split systems place one or more indoor heads in rooms and connect to an outdoor unit. Some homes add ducts in attics or basements. And in many climates, heat pumps, which provide both cooling and heating, are now considered alongside traditional air conditioners whenever cooling equipment is replaced.
A thorough contractor will visit the home before quoting. Expect questions about rooms that are hard to cool, how long you plan to stay in the house, noise concerns and your budget. You should also expect them to look at the electrical panel, the location for the outdoor unit and the condition of the ducts and indoor equipment.
What the work usually involves
- Refrigerant charge and commissioning. After installation, the system should be evacuated, charged and tested for proper operation.
- Line set and electrical. Refrigerant lines may be reused or replaced, and a dedicated circuit and disconnect are typically required.
- Load calculation. Sizing should come from a calculation of the home's heat gain rather than a rule of thumb.
- Pad and placement. The outdoor unit needs a stable, level base and adequate clearance for airflow and service.
- Walkthrough. A good installer explains filter changes, thermostat settings and warranty registration.
- Permits and inspection where required.
- Equipment matching. The outdoor unit, indoor coil and furnace or air handler should be compatible to achieve rated efficiency.
Things worth considering
- Oversizing is a common problem. An oversized system can cool quickly but cycle often, leaving humidity and uneven temperatures.
- Efficiency is rated in SEER2. Higher-rated units use less energy but cost more; the payback depends on how much you use cooling.
- Noise varies by model. If the outdoor unit will be near a bedroom or patio, ask about sound ratings.
- A heat pump may be worth comparing, since it can provide both cooling and heating with one outdoor unit.
- Matching with an older furnace may limit options. Some high-efficiency systems require a variable-speed blower.
- Warranty registration often has a deadline. Ask who handles it and keep the paperwork.
- Get comparable quotes. Make sure bids specify the same equipment tier, scope and included items.
Local notes for Castle Rock
At higher elevations, thinner air affects combustion and airflow, and gas furnaces are often derated or configured for altitude according to manufacturer instructions. Ask whether equipment is set up for your elevation.
Colorado's dry climate means many households consider humidification in winter, while summer cooling loads can be significant on hot, sunny days. Large day-to-night temperature swings are also common.
We take inquiries from Castle Rock, Castle Pines, Parker, Larkspur, Franktown.
What to have ready
- If you smell gas or suspect carbon monoxide, leave the home and contact your gas utility or emergency services first, before sending any inquiry.
- List times you can be reached and when someone can provide access.
- Mention what you have already checked, such as the thermostat batteries and settings, the filter and the breaker.
- Share the approximate square footage of the home and how many levels it has, especially for replacement quotes.
- Note the make, model and approximate age of your furnace, air conditioner or heat pump. The label is usually on the side of the unit or inside a panel.
Signs to slow down
- Pressure to buy immediately with a deal that expires the same day.
- Claims that equipment is dangerous without explaining the specific problem or showing you what was found.
- No written proposal that lists the equipment model numbers, scope of work and permit responsibility.
- No explanation of manufacturer warranty registration or labor warranty terms.
- Reluctance to show license or insurance information.
Questions worth asking
- Will you perform a load calculation, and can I see the result?
- What equipment do you recommend, and what are the alternatives at different price points?
- Is a heat pump worth considering for my home?
- Will you replace the line set and indoor coil, or reuse them?
- Does the quote include permits, electrical work, the pad and removal of the old unit?
- How will you verify the refrigerant charge and airflow after installation?
- What warranties cover the equipment and the labor, and who registers them?
- Are there current rebates or incentives that apply?
Frequently asked
- What size air conditioner do I need?
- The right size depends on your home's insulation, windows, orientation, air leakage and layout. A load calculation is the reliable way to determine it.
- How long does an AC installation take?
- A straightforward replacement often takes a day. New ductwork, electrical upgrades or a complex placement can add time.
- Are ductless mini-splits a good option?
- They are a common choice for homes without ducts, additions or specific rooms. Comfort and cost depend on the number of zones and the home's layout.
Related topics
- Ductwork and Indoor Air Quality: Duct sealing, repair, cleaning and indoor air quality options, plus what to ask an HVAC contractor.
- AC Tune-Ups and Maintenance: What an air conditioning tune-up includes, why maintenance matters, and questions to ask about service plans.
- Thermostats and Controls: Smart and programmable thermostats, zoning and controls, and what to ask an HVAC pro before upgrading.
Tell us a little about what you need, and we'll get back to you about air conditioning installation.