Lentz is president of Lentz Engineering Associates (Sheboygan Falls, WI). He is a graduate of the University of Wisconsin, Madison, with a Bachelor of Science in Mechanical Engineering, and a frequent Speaker at ASHRAE Annual and Winter Meetings and has been very active with respect to ANSI/ASHRAE Standard 62.1. He is a member or corresponding member of six ASHRAE Technical Committees, and has served as chairman of ASHRAE Technical Committee TC 9.8- Large Building Air Conditioning Applications, and vice chairman of ASHRAE TC 5.7-Evaporative Cooling. He has been nationally recognized by the DOE for having successfully developed, tested, and proven several advanced HVAC system strategies designed to exceed the performance requirements of ANSI/ASHRAE/IESNA Standard 90.1 - Energy Standard for Buildings Except Low-Rose Residential Buildings, while meeting or exceeding the requirements of and ANSI/ASHRAE Standard 62.1 - 2004, Ventilation for Acceptable Indoor air Quality.
In the conclusion of this pair of articles, the author delivers opinion and documentation with equal force. Making the argument that traditional VAV is too troublesome regarding meeting ASHRAE 62.1 and 90.1, he also explains how those same standards are pushing designers in the right direction. The destination? A new era for VAV and new efficiencies for their applications - but shining a little light down this path reveals just how fraught with peril the designer’s journey can be.
In this forthright first installment, the author makes the argument that VAV as practiced for the last 50 years has become not only outdated but unable to keep up with the standards that are supposed to guide it. On the upside, circumstances point the way toward a revitalized, high-efficiency era for VAV. But first, let’s take stock of the status quo.
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.