Laboratory Design Newsletter 2012 Selected Abstract

Energy-Efficient Fume Hoods: Case Studies From New Zealand

Ken Collins, Lab-works Architecture

Abstract

New Zealand is renowned for its clean, green image. Sustainability and energy efficiency are essential aspects of successful laboratory design that go hand-in-hand with this ideal. As a small country, New Zealand also needs to be able to compete on the world stage, and environmentally friendly, cutting-edge research facilities are an important way to attract talent and innovation. The Alan MacDiarmid Building at Victoria University of Wellington is a world-class research and teaching facility that demonstrates the benefits of using energy-efficient fume hoods.

The Alan MacDiarmid Building integrates the schools of biological, chemical, and physical sciences, including laboratories, clean rooms, teaching spaces, and offices. The project team included Lab-works Architecture as the specialist laboratory architects; Beca as heating, ventilating, and services engineers; and Jasmax as the principal architects.

The design of the Alan MacDiarmid building focused on environmental sustainable design principles, and adhered to guidelines from the New Zealand Green Building Council and Labs21. Sustainable features include solar hot water heating, a central high-efficiency chiller, façade modeling to maximize natural daylight, rainwater harvesting, and environmentally friendly building materials.

However, the services within the laboratories, especially those associated with fume cupboard extraction, are the most significant consumers of energy in this building. A key to reducing the Alan MacDiarmid Building's energy use was to reduce the extent of the loss of conditioned air through fume cupboard extraction.

Unlike the USA, New Zealand building regulations do not allow manifolding of flues, meaning that each fume cupboard must have a separate flue. One of the innovations in this building was the development of 12-foot-wide, three-person fume cupboards using a single exhaust system that saved significant space within ceilings and riser runs.

The regulations also require an average face velocity of no less than 100 feet per minute to provide sufficient air through the sash for safe operation of the fume cupboard. Typically, this means that a 6-foot-wide fume cupboard, fully open, removes 1,500 cubic meters per hour of conditioned air from the laboratory.

The fume cupboards and the air conditioning were both designed as VAV-interactive systems tied into a smart building management system. When any fume cupboard sash is raised or lowered, that laboratory air conditioning system immediately adjusts the amount of makeup air, maintaining the laboratory air pressure as required and the integrity of the fume cupboard. The result is that, when sashes are closed, the amount of makeup air required to a laboratory is significantly reduced from when the sashes are fully open.

By using New Zealand fume cupboard manufacturer Thermoplastic Engineering's (TPE's) innovative EcoAir technology (which uses the variable-flow control system), the amount of waste of conditioned air and cost of makeup air were significantly reduced. TPE's EcoSash system, which automatically adjusts the fan speed in proportion to the sash height, was also included. A sensor automatically lowers the sash to its lowest position after a short period of inactivity, dramatically increasing the fume cupboard door closure percentage, further reducing air conditioning demands and running costs.

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Building performance was tested over a seven-month period, with data logged 24/7, including every sash change. Half the test period was with the EcoSash system in operation, the other half with sashes managed manually by users.

Typically, a laboratory performs well if the fume cupboards are in the lowered position 50 percent or more of their operating time. With emphasis placed on good fume cupboard management, the laboratory users in the Alan MacDiarmid Building were able to increase that percentage of closure to 74.6 percent. However, with the EcoSash system in operation the closed position rose to 91.2 percent.

The reduction in air extraction and consequential makeup of conditioned air directly results in significant energy savings to the building. In this project, the energy savings for each fume cupboard per year are estimated at NZ$750 to NZ$1,900. This study demonstrates the advantage of using the EcoSash system to monitor and control sash closure rates rather than relying on laboratory users having a good culture and management system.

The Alan MacDiarmid building has demonstrated to Victoria University how the attention to sustainable design has resulted in reductions in the running costs of their building.

Biography

Ken Collins, a registered New Zealand architect, has been a director of Lab-works Architecture since 1982.

Mr. Collins has extensive experience in the design and construction of laboratories throughout New Zealand and in Australia. Mr. Collins has initiated many advances in design and construction including room layout, benching systems, safety stations, and chemical and gas use in his 20 years of designing laboratories.

He is a regular participant and has presented at the Labs21 Annual Conference and laboratory conferences in Australia, Asia, and New Zealand.

Mr. Collins has assisted in writing Australian and New Zealand laboratory standards (AS/NZS 2892:2010) and developing best practice and operation procedures for many of his clients.

Lab-works Architecture's clients include Government laboratories (CRIs), hospital laboratories, universities, and private companies.

Mr. Collins' focus is on assisting clients to achieve competitive advantage through design, improving the efficiency, accuracy, safety, and sustainability of their facilities.