Laboratory HVAC Systems Thermal Energy Reduction Through the Use of Separate Make Up Air and Space Conditioning Systems

Philip Bartholomew, PE, CUH2A

The presentation will expand on the approach presented in the February 2004 ASHRAE Journal. It will include the information of the article as applied to standard research facilities as well as investigate the benefits of applying this basic method to animal holding and bio-containment facilities.

The use of make-up air systems coupled with independent space conditioning systems for laboratories is investigated. As compared to standard single system VAV or constant volume air conditioning systems this approach provides substantial year round reduction of chiller and heating requirements of up to 60 to 70 percent.

It will be demonstrated that this approach can fully eliminate the energy wasteful processes of:

• Overuse of outside air above that required for ventilation
• Sub cooling supply air to provide dehumidification
• Using reheat year round to provide space temperature control. Also this approach allows for a very effective use of heat recovery.

The use of room temperature and humidity neutral air from the make-up air unit allows for a unique passive air delivery scheme to make-up air exhausted from the spaces. This allows for a substantial reduction in supply air ductwork and terminal control boxes as well as the requirements for sophisticated controls required for a conventional laboratory air conditioning system.

The net result of this approach is lower first costs as well as operating costs, improved containment of contaminants within the laboratories, simpler control systems, smaller chiller and boiler equipment, and improved acoustical conditions within the spaces.

Labs21 Connection:

The approach taken is a comprehensive departure from the standard HVAC approach used for laboratories and is not an incremental improvement of one aspect of these systems. Its design is the result of understanding how conventional systems are energy inefficient and how those aspects can be avoided.

Different methods and HVAC systems were presented to the owner and discussed as to how they support his goals. The decision by the owner to use this approach was based on energy conservation savings and economic benefits.

Biography:

Philip Bartholomew is a registered engineer practicing mechanical engineering for more than 25 years. He has worked primarily on laboratory projects with both academic and research and development facilities for the last 10 years.

Mr. Bartholomew speaks and writes frequently on the subject of HVAC innovations within the laboratory environment. His work with make-up air heat recovery at Haverford College was published in the February 2004 ASHRAE Journal as well as in Consulting Specifying Engineer. In 2002, he received a merit ARC award for advancing, reinvigorating, and cultivating excellence in engineering from Consulting Specifying Engineering for his work on the Integrated Natural Science Center at Haverford College.

A 1977 graduate of Pennsylvania State University with a Bachelor of Architectural Engineering, Mr. Bartholomew is a member of the American Society of Heating Refrigeration Air Conditioning Engineers.

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