Installation Standards & Sizing Guidelines: Standard residential spaces require approximately 500 to 600 BTU per square metre (approximately 3,412 BTU equals 1 kW of thermal capacity), with glazed conservatories requiring up to 850 BTU/m² due to solar gain. Seasonal efficiency is rated by SEER (Cooling) and SCOP (Heating), ranging from A+ on value systems up to ultra-efficient A+++ on premium inverters. Complete installations incorporate outdoor condenser positioning, anti-vibration wall brackets, insulated copper refrigeration line sets up to 15m, condensate drainage, and dedicated electrical isolator wiring by certified F-Gas technicians.