The primary purpose of the Green HVAC is to save energy while maintaining a well regulated environment inside the shelter. This is done by monitoring the inside and outside environment and intelligently choosing the least expensive mode of operation, while limiting the inside environment to a user settable temperature range.
Energy savings are accomplished by several means. The Green HVAC runs at -48VDC, just like the rest of the telecomm equipment in an equipment shelter. This means there is full backup, with redundancy, during AC mains outages (with practical reductions of power usage). Air conditioning (mechanical cooling) is variable, using only the energy necessary to maintain temperature and only when needed.
Conventional AC compressors have high inrush currents and poor power factor correction, but the Green HVAC has neither of these problems. Fans are run only at the speeds necessary to maintain the specified internal temperature. Dampers are dynamic, allowing the introduction of outside air when safe and appropriate.
A simple user interface is provided for observing temperatures, set points and modes of operation, while eye-catching LEDs alert the user of error conditions. Secure local and remote monitoring and control are duplicated using SNMP or any web browser via the internet or intranet.
The Green HVAC handles unusual conditions. In the case of smoke detection, dampers are closed and everything else is shutdown by the Emergency Vent system. This same Emergency Vent system overrides failure of the main circulation fan and provides independent thermostatic ventilation of the shelter until servicing can be performed. This Emergency Vent system even has its own power feed and circuit breaker, making it, truly, electrically independent.