Carrier has released its newly designed variable air volume (VAV) WeatherExpert™ 48/50LC 6- to 23-ton packaged rooftop units. The newly designed WeatherExpert VAV models, available from 23 tons down to 6 tons, use a dedicated i-Vu® controller that links communication between the system zone terminals and the unit to efficiently adjust the air flow and compressor stages that are required.
Pressure independent control valves proved to be a key in wringing the benefits out of smartly managed chilled water temperature, but that wasn’t all. Airside energy recovery, desiccant dehumidification to eliminate reheat in operating room environments, and upgrading to ECM fan systems have all contributed to this hospital’s fiscal wellness.
While mechanical energy codes may lag relative to the efficiency targets of some other codes , the expansion of VRF into a wider range of equipment makes it easier than ever to exceed expectations. Perhaps more importantly, its incorporation into heat pumps, dehu-midifiers, compressors, and more represents more flexibility in delivering an effective retrofit without a total system overhaul.
Sometimes it’s less important to think outside the box than to notice that the stuff inside the box has changed. In the case of airside economizers, more modern components and seasonal opportunities can make things work swimmingly.
Leaning on experience and data from various K-12 cities and projects, the author pursues some less conventional design approaches. They may revolve around radiant heating and/or cooling, but depending on school size and other factors, the smart use of heat recovery, DOAS, and improved central plants could also put a project on the HVAC honor roll.