Variable Volume & Temperature in Cold Climates: Zoned Comfort Promised... Can it deliver?

摘要

The focus of this article is the performance of a specific type of heating, ventilation, and air conditioning (HVAC) system operating in cold climates, known as variable volume and temperature (VVT). Information was gathered about system performance in an 8250 combined degree day climate at approximately 44°N latitude in the Eastern United States. The observations are based on the experience gained from installing new systems, retrofitting controls on existing systems, system commissioning, and responding to client distress calls of both newly installed and existing VVT systems, from 1987 to the present. The results indicate that VVT systems are most often favored for low first costs but lead to significant issues with comfort, excess operational expense, and tenant retention problems.