Planning authorities are shifting away from targets for proportions of renewables and moving towards general carbon reduction.
Heat pump technology could be a very effective way of meeting those goals and the change in approach and could also benefit cooling technology according to a leading sustainability consultant.
Jodi Willis, director at sustainability specialist MTT-Sustain said “We think we will be seeing less significance placed on a renewables element and more on low and zero carbon emissions. It makes more sense.”
Mr Willis’ view is that biomass boilers are no longer the best bet for compliance, a fact that will benefit air source heat pumps (ASHPs) particularly, he said. “With its NOx particle emissions and delivery requirements, biomass is not the saviour it was initially. ASHPs are a viable technology for Part L 2010 and they are is BREEAM rated as a LZC (Low or Zero Carbon) technology.”
He called for consultants to put aside conventional approaches and use technology like heat pumps creatively. “We as building services engineers need to be a lot more novel and innovative in design, we shouldn’t just be putting in boilers and chillers.”
MTT-Sustain has been pioneering in its use of large volumes of ASHPs to preheat water in integrated heating schemes, such as student blocks and community heating. In one community heating scheme, 530 units with a combined capacity of 3.5 MW have been specified to preheat water from 40 deg C to 45 deg C. Whilst the units take 20 per cent of the heat load, they provides a 4 per cent additional carbon reduction for the developer – and a £500,000 saving over boilers alone.
On another student block scheme the firm has demonstrated an 18.3 per cent reduction in carbon by specifying ASHPs to preheat water for feeding to conventional boilers on each floor.
The consultant noted that for many authorities, heat pumps were still required to be used for heating only for renewables compliance so where cooling was required, they specified additional chillers although absorption chiller trigeneration systems were becomingly increasingly viable if part of a centralised energy centre.
But Mr Willis added that some authorities are now in the early stages of bringing cooling back into the renewable equation, within the wider carbon targets.
He said:: “The Greater London Authority has just announced that ASHPs are renewables for both heating and cooling. And we’ve just had one authority accepting VRFs as a renewable technology for cooling and heating.”
He added that there would be more opportunities for technology providers as clients aimed more for BREEAM Excellent status. “One developer said he could get an extra £2.50 a square foot extra for an Excellent rating.”