Design Solution · HVAC & Energy
Design Solution · Dream about it
Swap gas boilers for air-source heat pumps to eliminate on-site combustion.
Fossil-fuel boilers are replaced with air-source heat pumps, removing on-site gas combustion and shifting heating onto an increasingly decarbonised electricity grid. Combined with measures such as variable-air-volume fans and BMS controls, this is a core lever in portfolio heat-decarbonisation plans.
Replacing gas boilers with air-source heat pumps is the primary heat-decarbonisation lever for the existing building stock, and commercially it is well past the experimental stage — millions of units are operating globally and UK policy actively incentivises it. The physics is settled: removing on-site combustion shifts the carbon burden to the grid, where it falls as grid intensity declines, which means the carbon case improves automatically over the building's life without further intervention. On a retrofit, the constraint is nearly always the heat distribution system rather than the heat pump itself — ASHPs deliver at lower flow temperatures than gas boilers, so older radiator circuits often need replacement or supplementation to maintain comfort, adding cost and programme that can make the business case marginal in shallow retrofits. Fabric quality matters more here than in any other intervention: a poorly insulated building drives the heat pump harder, pushes running costs up, and produces seasonal performance coefficients well below lab conditions. No evidenced deployments are logged against this record, which is a data gap rather than a credibility problem — the technology is proven, but the design team should model actual seasonal COP against the specific fabric condition before committing to the strategy.
#heat pump #ASHP #decarbonisation #heating #retrofit