Specifying Air Source Heat Pumps for UK commercial projects

It’s A Fair COP – Specifying ASHP in the UK

As a specialist in the design and provision of domestic hot water (DHW) and heating for commercial projects, Adveco is especially conscious of the need to correctly size and rate appliances for what are typically bespoke system designs. When specifying Air Source Heat Pumps for UK commercial projects, correctly establishing efficiency and calculating reductions in CO2 emissions is perhaps the most important element, given their specification for sustainability is increasingly a major facet of the investment in a building’s HVAC systems.

Adveco has now extended its range of commercial ASHPs with the introduction of the Adveco L70. This high-capacity air-to-water monobloc heat pump is designed for the UK climate providing hybrid domestic hot water (DHW) and heating. In conjunction with Adveco’s bespoke application design, the L70 offers a comprehensive response for sustainable heating and hot water, providing high-efficiency, low-emission, low cost to operate systems for the life of a commercial building.

Rated 70kW for typical UK operation at 5°C but climbing to a maximum 90 kW from a single compact unit, and with a seasonal coefficient of performance (SCOP) as high as 4.08 the L70 is perfect for large scale commercial applications and can operate as part of a cascade installation for projects demanding greater capacity.

With ASHPs offering greater efficiencies in low-temperature systems, the high-temperature demands of commercial DHW applications can be a challenge. Achieving working flow temperatures up to 60°C, the L70 supplies preheat for hybrid applications composed of combinations of plate heat exchangers, buffer vessel, with calorifiers, gas-fired boilers or direct-electric water heating providing essential additional heat to meet commercial requirements.

When analysing the value of an ASHP in terms of reducing CO2 emissions Adveco employs the carbon intensity figures from the new SAP10, with like-for-like calculations for 1 kWh of output, benchmarked against a modern, high-efficiency gas-fired system. When describing the efficiency of an ASHP, working flow water temperatures of 35°C are typically cited, but it needs to be recognised that this is insufficient for commercial applications. Even if a commercial building has achieved Passivhaus standards 35°C is not going to be hot enough to safely provide DHW. For this reason, Adveco recommends calculating emissions at a working water temperature from the ASHP of 55°C, this is then hot enough to provide realistic levels of preheat for a commercial hybrid DHW system.

Additionally, attention needs to be given to the Ecodesign established European temperature zones when calculating real-world figures. For most of the UK, the relevant defined temperature zone is ‘average’, where the lowest annual reference temperature for the ASHP’s SCOP is taken to be -10°C. For some Southern and Western UK regions, the ‘warmer’ Ecodesign temperature zone can be applied for calculation, where the lowest the reference temperature will only fall to 2°C. So give consideration to a project’s location when assessing potential reductions in CO2 emissions from the inclusion of ASHP in an application.

Designed to operate between 20°C and +35°C, Adveco’s L70, at -10°C can still easily generate working water temperatures of up to 55°C and will reduce CO2 emissions by almost 63%. Under the warmer climate zone’s conditions emissions can be reduced by almost 70% using a SCOP of 3.47.

Able to draw and transfer thermal energy from the air, under the right circumstances ASHPs represent an efficient way to significantly reduce the carbon emissions of a building. This does come at a higher price point compared to traditional gas-fired systems, so this can be an impediment to their adoption if sustainability gains alone are not enough.

Discover more about Adveco’s growing range of Air Source Heat Pumps