systems that were used in the VRFs could not handle the high-ambient conditions. That was the technology then, but they have improved the machines; they have improved the protection for the inverter systems, which can withstand high-ambient temperatures of 52 degrees C.” Other than the claims from industry experts, General Services Administration’s (GSA – an independent agency of the United States Government) Green Proving Ground (GPG) programme assessed the technology and found that VRF systems can achieve 34% and higher HVAC energy cost savings. GPG commissioned researchers at the Pacific Northwest National Laboratory (PNNL) to evaluate the technology. PNNL’s evaluation was based largely on a critical survey of the available VRF literature and discussions with industry experts. Researchers also reportedly took into consideration a partial VRF installation at GSA’s Moakley Federal Court House in Boston, Massachusetts, four additional installations in the Pacific Northwest, a review of VRF simulation work, a hypothetical application of the technology to selected parts of the GSA portfolio, and a lifecycle cost analysis (LCCA) that compares VRF technology with a Variable Air Volume (VAV) system with electric reheat. PNNL’s evaluation indicated that VRF technology merits GSA’s findings and assessment.1
As a consultant, we need to know the performance of the equipment at 50 degrees C
in the temperature range by two degrees C. For VRFs, it is supposed to be half a degree C. Furthermore, he believes that VRF systems have the ability to control the functioning of the air conditioning unit based on real demand, which means for every room there can be a single control. Energy use can, thereby, be rationalised based on actual use, rather than through the forced switching on and off of the machine. All these factors, concur industry experts, have increased the demand for VRF systems.
Demand and supply
Jabbar enumerates several reasons for the growing demand for VRFs: Their high efficiency; a need perceived by the market and governments for energysaving products with environmentally friendly refrigerants; the ongoing advertisement campaigns and training sessions conducted by suppliers and manufacturers for the region; and the use of DC compressors, especially for markets with electricity shortage, such as in Iraq. “VRF system is going to be one of the players of the market competing against the chillers and standalone systems, naturally because of their energy efficiency,” agrees Kandasamy Anbalagan, Managing Partner at Proleed Engineering Consultants. Ahmed corroborates this view, suggesting that VRF is about energy conservation and better quality comfort – a normal air conditioner would swing
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