Heat Pumps

Heat Pumps

Collaborating with Heat Pump Specialists

Europe is significantly more advanced with examples like the 14MW Drammen water sourced heat pump project which is well established and provides 85% of the hot water for the city. We are working closely with the UK’s leading heat pump manufacturer; who delivered the Heat Pump energy scheme in Drammen, Norway.  

How are Heat Pumps energy and carbon efficient?

Heat pumps rely on electricity; their environmental credentials are often tied to the national grid, but as this decarbonises, heat pumps provide greater carbon reductions and are now regularly considered as a potential solution for projects of all sizes.  With access to growing resources of renewable electricity, electrification of the UK’s heating infrastructure is a core strategic ambition and heat pumps are perfectly aligned with planned updates to legislation.

This optimism for the technology is shared by the UK government, with The Energy Secretary describing water source heat pumps as "game changing" and the government setting a target for 4.5million domestic heat pumps across the UK in addition to commercial and industrial installations.

Types of Heat Pumps

5^th generation district heating has steered the possibility of schemes which can operate at ultra-low temperatures (as low as 20°C/10°C flow and return), making a new type of heat pump technology viable.

Water Source Heat Pumps: recover the latent thermal energy absorbed by the sea, rivers & lakes and some systems work with slurries and effluent. Water is pumped into the system where the latent heat is used to compress a refrigerant. The refrigerant then transfers heat into the distribution system. Some of these systems will need to filter out debris in the water and ensure that no wildlife or ecology is harmed and in some instances will need permission from the Environmental Agency.

Ground Source Heat Pumps: These systems utilise the latent heat which is found in the ground and use one of two heat collection methods. One can be a horizontal coil collector which is pipe buried 1-2m below ground. Another is to utilise vertical coil collectors placed in a borehole ~100m deep depending on ground conditions. In both of these the pipe holds an antifreeze soluion which exchanges heat with the ground. The temperatures at these depths tend to be stable throughout the year and are not unduly affected by seasonal weather.

Air Source Heat Pumps: As their name implies, these systems rely on the latent heat in the air to generate heat and hot water. The efficiency of these systems is dictated by climatic operating conditions and the refrigerant used, but they have demonstrated they can operate with a COP in excess of 3 during spring/autumn conditions. Whilst air source heat pumps are regarded as the least efficient of the three types of heat pumps they are still attractive from a financial perspective with CIBSE stating that they can be more efficient than oil fuelled or condensing boilers. 

Ambient Loop & 5th Generation Heat Network Solutions 

5^th generation district heating has steered the possibility of schemes which can operate at ultra-low temperatures (as low as 20°C/10°C flow and return), making a new type of heat pump technology viable.

Ambient Loop schemes are a next generation technology which has the potential to transform the way we generate and use heat whilst delivering large carbon savings and meeting the government’s ambition of electrifying heat generation.  The system works by generating hot water from a central heat source, such as an air, ground or water source heat pump.  This water is circulated in a closed loop system and customers extract heat from this loop and then boost it via individual heat pumps within their properties to create heating and hot water.

As legislation and planning requirements become increasingly stringent, especially with regards to carbon emissions, it is predicted ambient loop systems will play a large part in the future of the UK’s heat generation mix.

Key Benefits of Heat Pumps

• Key technology to address the Energy Trilemma
• Eligible for funding under the Renewable Heat Initiative, although this is due to end in 2021.
• WSP estimate that heat pumps rather than gas boilers for heating and cooling could reduce the operating costs of commercial buildings by 25% whilst being approximately 25% cheaper to install and maintain
• BREEAM credits can be gained through the consideration of heat pumps alone via a Low Zero Carbon (LZC) feasibility study in accordance with ENE-04.
• Zero on-site emissions therefore improving air quality
• 250% seasonal Coefficient of Performance and can have a peak efficiency performance in excess of 300%
• 55% reduction in CO2 emissions factor electricity under 2018 draft version of the new Standard Assessment Procedure (SAP)
• Grid carbon factor is predicted to decrease by over 87% between 2018 and 2044, with heat pump carbon emissions decreasing by a similar amount over that period.
• 20% carbon reduction over Part L (This is 35% for the GLA London Plan.)