The amount of conditioned air to be supplied by a cooling system; usually the maximum amount to be delivered based on a specified number of cooling degree days or design temperature.
Design heating load
The amount of heated air, or heating capacity, to be supplied by a heating system; usually the maximum amount to be delivered based on a specified number of heating degree days or design outside temperature.
Design life
Period of time a system or appliance (or component of) is expected to function at its nominal or design capacity without major repair.
Design temperature
The temperature that a system is designed to maintain (inside) or operate against (outside) under the most extreme conditions.
Design tip speed ratio
For a wind turbine, the ratio of the speed of the tip of a turbine blade for which the power coefficient is at maximum.
Design voltage
The nominal voltage for which a conductor or electrical appliance is designed; the reference voltage for identification and not necessarily the precise voltage at which it operates.
Designer
One who designs houses, interiors, landscaping or other objects. When used it the context of residential construction it usually suggests that a designer is not a licensed architect. Most jurisdictions don't require an architectural license for most single family construction.
Desuperheater
An energy saving device in a heat pump that, during the cooling cycle, recycles some of the waste heat from the house to heat domestic water.
Detail
Information added to a drawing to provide specific instruction with a drawing, dimensions, notes, or specifications.
Detail sander
Detail sanders have a unique, triangular-shaped head geared for smaller, tighter and more detail-oriented jobs.
