Ontario Central AC Guide: Manual J Sizing, SEER2 Ratings & 2026 Installation Costs

Central air conditioning is standard in Ontario homes today. Whether replacing or installing new, here is a full 2026 guide.

Central AC vs Ductless Mini-Split
Central AC uses existing ductwork from one outdoor unit. Ductless mini-splits condition individual zones without ducts — ideal for homes without central ducting, for room additions, or targeted cooling upgrades.

Sizing: Manual J Required
Oversized AC short-cycles, fails to dehumidify properly, and wears faster. Undersized cannot handle peak summer days. Typical 2,000 sq ft Ontario home: 2.5-3 ton (30,000-36,000 BTU). Always demand a Manual J load calculation from your HVAC contractor.

SEER2 Efficiency
Canada mandates minimum SEER2 13.4 for new central AC. High-efficiency units: SEER2 18-22. Higher SEER2 reduces hydro bills under Ontario’s Time-of-Use pricing.

Installation Costs 2026
Central AC 2.5 ton, 16 SEER2: $3,500-$6,000 including permits and refrigerant. If air handler/coil also replaced: +$1,500-$3,500. Single-zone ductless: $3,000-$5,500 installed.

Permits
ESA electrical permit required. Refrigerant handling requires certified technician. Verify contractor licences and insurance.

Find Ontario HVAC contractors and discuss AC options at home.renovation.reviews.