What affects the cost

A price for HVAC work is built from a few pieces. In Illinois, a written contract with all costs listed is required for home repair or remodeling work over $1,000, and it must state the total cost, including parts and materials and any charge for the estimate. In Chicago, a licensed home repair business's written estimate must include the total cost of parts, labor, incidental services and any charge for preparing the estimate. For work charged by the hour, such as duct cleaning, the EPA suggests asking for an estimate of the number of hours or days the job will take. Ask what each line covers before you agree.

Source: Illinois Attorney General · City of Chicago · U.S. EPA

Bigger equipment is not better, and it can cost you more. ENERGY STAR says that if a unit is too large for your home, you will have less comfort and increased costs. Oversized equipment runs in short cycles that do not let it reach efficient operation. Oversized units tend to have shorter lives because short cycling, turning on and off rapidly, puts extra wear on the compressor. For room air conditioners, an oversized unit costs more to buy, wastes energy and does not cool any better.

Sizing is a calculation, not a guess. Your contractor can find the right size by using ACCA/ANSI Manual J, or an equivalent sizing tool. Expect the contractor to gather information about your house such as the level of insulation, the type and size of the windows, and the floor area. Your home may have changed since the old equipment went in, through additions or insulation improvements, or the old equipment may have been too large from the start. That is a good reason to ask how the new size was chosen.

Source: ENERGY STAR

The price to buy and the price to run are two different costs. The FTC says it's important to look at the energy efficiency and how much it will cost to run your new HVAC system. ENERGY STAR says a qualified furnace is 15% more efficient than a conventional furnace. It also says high-efficiency units, installed correctly, can save up to 20 percent on heating and cooling costs. In its guide to buying room air conditioners, the Department of Energy says an efficient product is cost effective when the lifetime energy savings exceed the up-front cost premium, if any, compared with a less efficient option. Ask for the running cost as well as the price when you compare options.

Care over the years affects cost too. The Department of Energy says a regular maintenance schedule can help reduce your heating and cooling costs by 10% or more and will prolong the life of the equipment. A dirty filter can increase energy costs and damage your equipment, leading to early failure. Too much or too little refrigerant makes a system less efficient, raising energy costs and shortening the life of the equipment.

Source: Federal Trade Commission · ENERGY STAR · U.S. Department of Energy

New equipment works through the ducts already in your home. ENERGY STAR says leaky ducts waste energy dollars and can also reduce airflow, resulting in reduced comfort. Poor system airflow can result in reduced efficiency, higher utility bills, overly damp air, reduced comfort and shortened equipment lifespan. The EPA notes that sealing duct air leaks can help save energy on heating and cooling bills. When some rooms are too hot or too cold, improper equipment operation, duct problems or inadequate insulation could be the cause. So ask whether an estimate looks at your ducts as well as the equipment.

Venting is another part of a furnace job to ask about. A direct-vent sealed-combustion furnace brings combustion air from outdoors through one sealed pipe and sends the exhaust outdoors through a second sealed pipe. Because its flue temperatures are cool, the intake and exhaust on a Category 4 direct-vent sealed-combustion condensing furnace can be made of PVC. The page on burning and venting explains how this works.

Source: ENERGY STAR · U.S. EPA · U.S. Department of Energy

Some HVAC work needs a city permit, and that is part of the job. Chicago's permit guide lists repairing an existing heating, cooling or ventilation appliance as work that needs no building permit, and notes that, except as it describes, complete replacement requires one. Replacing parts of an appliance without altering its function or decreasing its efficiency is on the same list. Replacing existing HVAC equipment with equipment performing the same function, even with a change of energy source, is work the city's Express Permit Program accepts. If an application turns out to be ineligible for that program, review and permit fees already paid are not refunded. For mechanical permit applications, the city lists a licensed general contractor, Class A, B, C, D or E based on total project cost. Ask whether a permit is included in your estimate and who will get it.

Source: City of Chicago

The refrigerant your air conditioner uses can shape your choices. Beginning January 1, 2025, certain technologies may no longer use high global warming potential (GWP) HFC refrigerants, and the rules cover installing new systems that use restricted HFCs. The EPA says homeowners can maintain and repair their systems throughout the useful life of the equipment, including replacing a faulty component with a similar R-410A component. R-22 can still be used to service existing equipment, including replacing failed components. There is no EPA mandate for converting existing R-22 equipment.

When you weigh a repair against a new system, the EPA names the factors. It lists availability of components, energy efficiency and total maintenance costs as things to consider when choosing between repair and a new system using a lower-GWP refrigerant. The repair or replace page goes deeper on that choice.

Source: U.S. EPA