Air conditioning in the United States: equipment, states, rules
Central AC, heat pumps, mini-splits, window and portable units — sized by the BTU math, judged by SEER2, priced in honest ranges. Then your state: DOE climate zone, cooling degree days, regional efficiency minimums and incentives.
Equipment
Central ACCentral AC explained for US homes: SEER2 minimums by region, honest replacement cost ranges, duct realities, a…Heat pumpUS heat pump guide: how air-source units cool and heat, honest installed cost ranges, cold-climate performance…Mini-splitDuctless mini-splits for US homes: honest cost per zone, where they beat central AC, sizing without oversizing…Window ACWindow air conditioners done right: BTU sizing by room, why U-shaped inverter units changed the game, install …Portable ACPortable air conditioners rated honestly: SACC vs ASHRAE BTU, single vs dual hose, real-world cooling losses, …
By state
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Guides
- Smart thermostats: where the savings actually come from
- Cooling a garage or workshop: what works and what the code forbids
- SEER2 explained: what the rating means on your bill
- Heat pump vs air conditioner: the real decision framework
- Central AC replacement cost: an honest 2026 breakdown
- Mini-split vs central air: which architecture fits your house
- HVAC tax credits and rebates: claiming what you are owed
- BTU sizing guide: matching cooling power to real rooms
- Window vs portable AC: the room-cooling showdown
- AC not cooling: the diagnostic order that saves a service call
- What it costs to run an air conditioner in the United States
- AC maintenance: the yearly rhythm that keeps a system honest
- Repair or replace your air conditioner: how to make the call
- AC thermostat settings: the numbers that actually save money
- Leaky ducts: the cooling you pay for and never receive
- R-454B and the A2L switch: what the refrigerant change means for you
- MERV ratings: choosing an AC filter without choking the system
- Upstairs hot, downstairs cold: fixing uneven cooling
- Whole-house fans and night flushing: cooling for pennies
- Reading an HVAC quote: how to choose a contractor without guessing
- Cold but clammy: why the house stays humid with the AC running
- Swamp cooler or AC: the dew point decides, not the thermometer
- Replacing only the outdoor unit: when it is fine, when it is a trap
- Single-stage, two-stage or variable-speed: the compressor decision
- The AC capacitor: the cheap part behind most summer breakdowns
- Water on the floor: the condensate drain, from clog to float switch
- Attic insulation and cooling: the load you pay to remove
- Auxiliary heat vs emergency heat: what your heat pump is doing
- Running your AC on a generator: what starts, and what only stalls
- AC short cycling: why it starts and stops every few minutes
- Winterizing the outdoor unit: covers, power and what actually protects it
- AC keeps tripping the breaker: reading the timing before you reset
- Installing a window air conditioner: brackets, seals and the right circuit
- AC making noise: what each sound is telling you
- HVAC permits: what a legal system replacement involves
- Ice on the coil: why an air conditioner freezes up
- Do heat pumps work in the cold? Reading capacity, not marketing
- Wildfire smoke and your AC: what keeps it out, and what pulls it in
- Dual fuel: pairing a heat pump with the furnace you already own
- Air conditioning in a rental: what a landlord owes you, and what you can install
- Ceiling fans and air conditioning: what the setpoint offset really buys
- Installing a mini-split yourself: what the law, the tools and the warranty allow
- HVAC warranties: the registration deadline that doubles your coverage
- Through-the-wall air conditioners and PTACs: the sleeve decides everything
- Paying for a new HVAC system: the finance choice that costs more than the equipment
- Recharging an air conditioner: what refrigerant costs, and why topping off is not a repair
- Reading the nameplate: your air conditioner’s size, age, refrigerant and circuit
- Replacing an evaporator coil: the indoor failure with the widest quote spread
- Does a home warranty cover your air conditioner? Reading it before August
- HVAC zoning: motorized dampers, a thermostat per floor, and the bypass duct that undoes it
- Homeowners insurance and your air conditioner: what a claim actually pays
- Weak airflow: static pressure, the return side, and the blower that cannot win
- Cleaning a mini-split: the blower wheel, the pan, and the smell that keeps coming back
- AC compressor replacement: the repair that is really a system decision
- Where the outdoor unit goes: clearances, noise and the capacity a fence costs you
- When the AC cannot keep up: design temperature and the heat-wave gap
- Geothermal heat pumps: what the ground loop costs and what it buys