A field test involving eight single-family houses was performed during the summer of 1991 in Scottsdale, Arizona, to evaluate the potential of reducing air conditioning electricity consumption and demand by insulating the exterior masonry walls. Total per-house costs to perform the installations ranged from 3,610 to 4,550 dollars. The average annual savings was estimated to be 491kWh, or 9% of pre-retrofit consumption. Peak demands without and with insulation on the hottest day of an average weather year for Phoenix were estimated to be 4.26kW and 3.61kW, for a demand reduction of 0.65kW (15%). Concludes that exterior masonry wall insulation reduces air conditioning electricity consumption and peak demand in hot, dry climates similar to that of Phoenix. Reductions in peak demand are a primary benefit, making the retrofit worthy of consideration in electric utility conservation programmes. The economics can be attractive from a consumer viewpoint if considered within a renovation or home improvement programme.

KEYWORDS: air conditioning, electricity consumption, energy conservation, thermal insulation, USA, housing, masonry, walls, testing, peak load, deserts, economics, costs, summer, calculating.