Air conditioning

From Home Services Wiki, an independent reference for home services

Central air conditioning moves heat out of the home with a refrigerant cycle. The outdoor condenser and indoor coil work together, and both need regular care.

Draft. Some reference links and cost figures are still being verified.

Central air conditioning moves heat out of the home with a refrigerant cycle. An outdoor condenser and an indoor evaporator coil work together, and both need regular care to keep efficiency and comfort up.

Quick facts
Question	Short answer
How long does it last?	DOE's Energy Saver infographic lists central air conditioners at 15 to 20 years, and room units at 10 to 15 years.
When is it time to replace?	ENERGY STAR advises considering replacement once a heat pump or air conditioner is more than 10 years old, and a furnace or boiler at 15 years. Repair costs and efficiency matter too.
What does it cost?	Fixr's 2026 guide puts an average AC repair at about $375. Replacement costs vary by size, efficiency, and ductwork, so get a local quote.
When do I need a pro?	Any refrigerant work, compressor or electrical work, and any leak. Refrigerant handling requires EPA certification.

How it works

Refrigerant absorbs heat from indoor air at the evaporator coil, then releases it outdoors at the condenser. A compressor drives the cycle, and an expansion device controls refrigerant flow. The indoor air handler moves air across the coil and through the ducts. The cycle needs the right refrigerant charge to work efficiently.

Efficiency ratings

Ratings to know
Rating	What it measures	ENERGY STAR reference
SEER2	Seasonal cooling efficiency under the current federal test method	Heat pump split systems: 15.2 SEER2 minimum under ENERGY STAR's current criteria; check the current version before buying
EER2	Cooling efficiency at a single high-temperature test point	Central AC split systems: 12.0 EER2 in Version 6.1
Refrigerant type	The refrigerant the new system uses; the EPA transition rules set requirements	See the codes section below

ENERGY STAR's current specifications should be checked before purchase because the agency has been revising its central AC criteria.

Warning signs

Symptoms and next steps
Symptom	Possible cause	Next step
Warm air from vents	Low refrigerant, a dirty coil, or a failing compressor	Turn the system off and call a licensed technician
Short cycling	Oversized unit, dirty filter, or a control problem	Check the filter; call a technician if it continues
Ice on the coil or refrigerant lines	Restricted airflow or low refrigerant	Turn the system off to thaw, check the filter, and call a technician
Water leaking near the indoor unit	Blocked condensate drain	Clear the drain if you can reach it; call a technician if the leak returns
Rising energy bills	Declining efficiency, duct leaks, or refrigerant problems	Schedule a tune-up and a duct inspection

Maintenance

Routine maintenance
Task	How often	Who
Replace or clean the filter	Check monthly; replace on the manufacturer's schedule	Homeowner
Keep the outdoor condenser clear of debris	Ongoing	Homeowner
Rinse the outdoor coil gently	Seasonally, with power off	Homeowner
Check the condensate drain	Seasonally	Homeowner
Professional tune-up	Once a year, ideally in spring before cooling season (ENERGY STAR)	Licensed technician

DIY or call a pro

Common tasks
Task	Homeowner?	Notes
Change the filter and clean debris	Yes	Turn the system off first
Clear the condensate drain	Yes	Use a wet-dry vacuum or the drain access; do not force tools into the line
Recharge or repair refrigerant	No	EPA certification required for technicians who handle refrigerants
Compressor, capacitor, contactor, or wiring work	No	Licensed technician; electrical shock and capacitor hazards

Codes and permits

AC installation and replacement typically need a permit, and mechanical codes such as the International Mechanical Code govern equipment and duct work.
EPA's Technology Transitions rule restricts refrigerants with high global warming potential in new equipment. A May 2026 EPA final rule reportedly removed the January 1, 2026 installation deadline for most residential and light commercial R-410A systems, with exceptions such as New York. Confirm the effective date and current requirements with EPA and your installer before buying.
Technicians who work with refrigerants must hold EPA Section 608 certification.

Cost

2026 cost ranges
Job	Typical range	Notes
Central AC alone	Get a local quote	Varies by size, efficiency, and ductwork
Furnace and AC together (Angi)	Get a local quote	Ductwork and electrical upgrades add to the total

Equipment choice, efficiency, and home layout all change the price. Get written quotes that include a load calculation.

Regional notes

How conditions change the advice
Condition	What changes	Advice
Hot, humid climates	Long cooling seasons and high humidity loads	Size with a load calculation, not a rule of thumb, and check dehumidification
Desert climates	High peak loads on hot afternoons	Keep condensers shaded and clear, and maintain them before peak season
Coastal areas	Salt air corrodes outdoor coils	Consider coated coils and rinse them seasonally

Frequently asked questions

Is a bigger AC better?

No. A load calculation sets the right size, rather than a rule of thumb.

How do I know if my refrigerant is low?

Low refrigerant usually shows up as weaker cooling over time, sometimes with ice on the coil. Only a licensed technician can measure and recharge the system.

Can I keep using an older R-410A system?

EPA rules restrict new installations, not the use of existing systems. Repairs can usually use compatible components. Confirm the current rule before you buy a replacement.

Hiring checklist

Confirm the contractor is licensed and holds EPA Section 608 certification.
Ask for a load calculation and an equipment sizing report.
Compare SEER2 and EER2 ratings and the refrigerant type of each quote.
Confirm the permit, duct inspection, and warranty on parts and labor.

Glossary

Terms
Term	Meaning
SEER2	Seasonal energy efficiency ratio under the current federal test method
Condenser	The outdoor unit that releases heat
Evaporator coil	The indoor coil that absorbs heat
Condensate	Moisture removed from the air that must drain away
Section 608	EPA's refrigerant certification for technicians

Sources reviewed November 4, 2026. Independent professional review: pending. Confirm local rules with your building department.

Repair

Repair services
Service	When you need it	Typical cost (2026 guides)	DIY or pro	Permit usually?
Refrigerant recharge (R-410A)	Weak cooling, ice on the coil, or a known leak	Get a local quote; higher if a leak must be found and fixed	Licensed technician with EPA Section 608 certification	Usually not
Capacitor replacement	Compressor or fan will not start, or humming	Get a local quote	Licensed HVAC technician	Usually not
Compressor repair or replacement	Compressor failure	Get a local quote	Licensed HVAC technician	Usually yes for replacement
General AC repair	Any repair call	About $250 to $700, average about $375 (Fixr)	Licensed HVAC technician	Usually not

Maintenance

Maintenance services
Service	When you need it	Typical cost (2026 guides)	DIY or pro	Permit usually?
Annual AC tune-up	Once a year before cooling season	Get a local quote	Licensed HVAC technician	No
Condenser cleaning and rinse	Seasonally, with power off	Low cost; homeowner task	Homeowner	No
Condensate drain check	Seasonally	Low cost; homeowner task	Homeowner	No
Maintenance plan	Homeowners who want scheduled service	Get a local quote	Licensed HVAC company	No

Installation

Installation services
Service	When you need it	Typical cost (2026 guides)	DIY or pro	Permit usually?
Central AC replacement	Failed compressor or aging system	Get a local quote; see the Cost section	Licensed HVAC technician	Usually yes
Furnace and AC together	Both systems are aging	Get a local quote	Licensed HVAC technician	Usually yes

References

Categories: Heating and cooling (HVAC)