With the ever increasing demand on mechanical engineers to ensure that their designs comply with Part L or credits for BREEAM, here are our suggestions where using ROBUR’s gas absorption technology may assist.

Guidance for Part L* compliance in new buildings

  • Select “heating only”.
  • Under classification, select “Absorption heat pump”.
  • For fuel source, select “gas”.
  • Against the efficiency, input 165% as the standard GUE & 1.55% as the seasonal GUE.
  • Run the model.

The minimum efficiency stated in the 2010 non domestic building services compliance of an “Absorption heat pump” is 0.5%.

Following the above procedure should allow your project to obtain a “pass” first time with Part L, without the need for expensive photovoltaics (PV), which are normally required to offset when using other heating products.

Using these gas utilisation efficiency (GUE) and seasonal gas utilisation efficiency (SGUE) figures, coupled with the fact that it burns fossil fuel at source, Robur GAHPs will give you a much lower KG/CO2/m2 calculation when compared with conventional boiler plant or electric driven heat pumps, which suffer from power transmission losses.


We believe the following additional BREEAM credits are available when using gas absorption technology in preference to electric heat pumps.

NOX emissions (44 ppm) =2 points
GWP>10 (ammonia has a GWP of 1) =2 points
Low Carbon Technology (1-4 points available) =1 point minimum (realistic)
Built-on refrigerant leak detection =1 point


* Based on the 2010 edition of Part L and BREEAM.