Designing Functional Products in the Best Interest of the User — With a Factor 10 Reduction in Life Cycle Cost : Example, a (Solar) Airconditioning System

Abstract

There is increasing interest in Life Cycle Design with the purpose of raising sustainability and reducing energy and material consumption. By increasing energy efficiency, selecting more suitable materials and lessening maintenance requirements it is practical to reduce life cycle cost. Conventional Heat pump air conditioners operate to effect a healthy and comfortable indoor environment. They are large consumers of energy, partly due to the need to exhaust air (with consequent energy wastage) from the conditioned building so that healthy ventilation air may be introduced in its place. Rather than drawing all the energy from community electricity and gas supplies, the designer should design these systems so they recover as much energy as is feasible from both building exhaust air and the environment. A low life cycle cost solar air conditioner design is described that obtains under peak load more than 90% of its energy from a combination of building exhaust air and insolation with a reduction in life cycle cost approaching a factor of 10. In basic terms, with a reduction of a factor of 3 in energy consumption along with a life increase also of a factor of 3 it is possible to approach a factor of 10 improvement in product life cycle cost.