Why use glycols in HVAC systems?
- Trane Co., LaCrosse, WI (United States)
Glycols are used to prevent damage to heating, ventilating, and airconditioning (HVAC) equipment due to freezing and corrosion. Two glycols enjoy wide acceptance--ethylene glycol and propylene glycol. Both glycols have lower heat transfer characteristics and increased pumping requirements when compared to water. The loss of heat transfer and the increase in pumping power are influenced by temperature and the concentration of the fluid. The physical effects of glycol are almost unnoticed in heating systems where higher temperatures prevail. However, in cooling applications, the effect of glycol on system capacity and pump power must be carefully considered. Capricious addition of glycol to cooling systems is inappropriate. The effects of glycol can be mitigated by careful selection of equipment. This paper illustrates methods by which to reduce the impact of glycols when selecting cooling coils and chillers. Techniques such as increasing log mean temperature difference (LMTD) and modifications in coil circuiting or tube geometry can have a dramatic effect. The benefits of these techniques will be reviewed.
- OSTI ID:
- 349979
- Report Number(s):
- CONF-970668--
- Country of Publication:
- United States
- Language:
- English
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