Designers are over-specifying small power loads in offices by up to 40%, with knock-on effects on cooling requirements, the latest research by the British Council for Offices (BCO) has revealed.
The study, carried out by engineering consultancy Hilson Moran, monitored typical loads on 30 desks at a range of offices run by firms including PricewaterhouseCoopers, LNG and several engineering consultants. The results will inform the forthcoming revision to the BCO Guide to Specification, due out in September.
It found that at occupation densities of 10 sq m per person (most office space falls between 8-13 sq m per person) 40% less small power was actually required than buildings were designed to accommodate, and at the higher occupation densities of 8 sq m per person, power consumption rarely exceeded 19W/sq m, 24% lower than the load recommended in the previous 2009 BCO Guide.
“Although small power load accounts for only a fraction of the total energy consumed by buildings, maybe around 2%, specifying it properly can still save space and capital and operational costs related to power distribution and plant within buildings,” said Nigel Clark, technical director at Hilson Moran.
“Although small power load accounts for only a fraction of the total energy consumed by buildings, maybe around 2%, specifying it properly can still save space and capital and operational costs related to power distribution and plant within buildings.”
Nigel Clark, Hilson Moran.
“By refining size of plant and cabling to what it actually needs to be, the space needed to house it can be reduced and because commercial offices form a significant proportion of UK building stock, this could have a major impact across the UK. The study was ultimately about fine tuning design to make specification more efficient, too many designers are reliant on standard building specifications because they think that’s what the market wants.”
The study claims reduced power loads are the result of the latest computer equipment, PC processors and fans etc, which run more efficiently than equipment manufactured three years ago. There is also a trend towards more mobile working, which means people are much less attached to their desks than previously, as well as increasing use of laptops, tablets and other smart devices. In the next few years, mobile and thin client technology is likely to reduce small power energy consumption in buildings even further, said the report.
For the first time, the study has confirmed that heating, ventilation and cooling (HVAC) loads should be lower than electrical loads going forward. Clark added: “In the past, putting in 20W per sq m electrical load, you would match it with the same cooling load. But we found that computer equipment now functions in peaks and consumption is so shortlived that HVAC is often not required. Our findings suggest that cooling loads could be 4-5 W per sq m lower than electrical loads, which has never been acknowledged before.”
Revised specification guidance on small power load will be included in the next BCO Guide, due out in September.
