Window Air Conditioners

Measure the room square footage and match it to the unit BTU rating: roughly 5,000 BTU for up to 150 sq ft, 8,000 BTU for 150–350 sq ft, 10,000–12,000 BTU for 350–550 sq ft; increase capacity for sunny rooms or high ceilings and decrease slightly for shaded rooms

Check the ENERGY STAR certification and the unit's EER or SEER rating (higher is more efficient), look for variable-speed compressors or multiple fan speeds, and consider programmable timers and eco modes to reduce runtime and electricity use

Noise varies by model and capacity; manufacturers often list sound levels in decibels (dB). Compare dB ratings—lower dB numbers indicate quieter operation—and read user reviews for real-world noise impressions near the expected operating mode (low/medium/high)

Confirm your window type, opening dimensions, and weight capacity; measure opening height and width and check if the unit fits a single- or double-hung window or requires a sleeve; verify whether you need additional brackets, electrical outlet capacity, or a dedicated circuit

Clean or replace washable filters every 1–3 months, vacuum coils and fins periodically, clear debris from exterior components, and store or cover the unit in winter to prevent corrosion and pest intrusion

Look for built-in air filters (washable or replaceable), dehumidification settings, oscillating louvers or adjustable airflow directions, and ionizers or washable electrostatic filters if improved particulate removal is desired

Prices typically range from lower-cost basic units in the lower hundreds to higher-capacity or feature-rich models several hundred dollars higher; more expensive units commonly offer higher BTU, better energy efficiency, quieter operation, and added features like Wi‑Fi and advanced controls