NY-91-15-3 -- An Energy Analysis of Low-Temperature Air Distribution Systems and Reduced Economizer-Cycle Cooling PDF

Low-temperature supply air systems are often used with an ice storage system to take advantage of the 34 deg F to 38 deg F chilled water available. By using a low-temperature air distribution system to provide primary air for space conditioning or process cooling. distribution equipment can be downsized to offer significant savings in first costs and often lower energy costs. However, some of the benefits of the natural cooling normally available in a conventional (55 deg F) supply air system will be low cost in a low-temperature supply air system. This is generally experienced in climates where a significant portion of the operating hours between 45 deg F and 60 deg F allow the use of the economiser cycle in a conventional system and otherwise require mechanical cooling in a low-temperature air distribution system. By using an hourly building energy analysis program to compare the energy use associated with a conventional (55 deg F) supply air system with the energy use of a low-temperature supply air system, quantifies the energy penalty associated with reduced economiser-cycle cooling in a low-temperature system at various locations throughout the United States and also shows that this energy penalty can be overcome by the savings in fan horsepower energy associated with the low-temperature supply air system.

KEYWORDS: low temperature, air distribution, economisers, cooling, ice storage, space cooling, energy conservation, comparing, calculating, energy consumption, USA, air conditioning.