Gama Aviation Ltd have two large heating units in their main engineering hangar at Farnborough Airport, which would run continuously throughout the day but never reach the thermostat set point of 14°C.
Following installation of the Airius system their HVAC system would achieve the thermostat set point with only one of the two heating units running. Once at the temperature set point the Airius system would then maintain the desired conditions with only the one remaining heating unit running intermittently.
In September and October of 2012 (PRE AIRIUS) the heating gas consumption was 2,356m³. In September and October of 2013 (POST AIRIUS) the heating gas consumption was 1,042.3m³.
If the weather was consistent each year then this would have shown a 55.76% saving. In reality the mean average temperatures based on figures provided by the MET Office were as follows:
September – 2012 13.4°C 2013 13.9°C
October – 2012 10.1°C 2013 12.7°C
This shows that in 2012 the temperature was 0.5°C lower in September and 2.6°C lower in October. A temperature change of 1°C can affect a building’s heating requirement by between 6-11% depending on the efficiency of the building.
If we take the worst case scenario and increase the heating gas consumption in 2013 by 5.5% for September and 28.6% for October, this gives a total increase of 17.05%, taking 2013 heating gas consumption from 1,042.3m³ up to 1,220m³.
This gives new comparable consummations with degree days taken into account of 2,356m³ of heating gas in September and October 2012 and 1,220m³ of heating gas in September and October 2013.
This gives a true saving of 48.22%.