Case Study - NATS, Prestwick Centre
EndoTherm was installed into a NATS air traffic control centre in Ayrshire, Scotland.
The Prestwick Centre in Ayrshire is NATS northern office. It is a 14,000 square meter mixed use
commercial building. The site is heated by air conditioned systems and fan coils which is powered by 5 x Ferroli 247.5kW boilers (combined rating of 1,237.5kW). The system was dosed with the closed system inhibitor (Chem Aqua 999).
Existing records of the system noted the combined system volume as being 14,000L needing 140L of EndoTherm. The site was also dosed with 30% Glycol which is commonly used as an anti-freeze.
A methodology adopting CUSUM and regression analysis was agreed by Endo Enterprises (UK) Ltd and NATS.
The monthly values of usage (kWh) over heating degree days (HDD) for the previous 15 months was plotted to establish a relationship of the building before any change occurred. The on-site kitchen usage is sub-metered and was removed from the gas values.
The trend-line equation was confirmed as: y = 168.31x + 110143. See graph below.
Note: Degree Days were taken from the on-site EGPK: Prestwick Airport
Using the trend-line equation. The predicted usage was taken for each month and compared with the actual usage on site.
|Month||HDD||Predicted Usage||Actual Usage||Difference||CUSUM|
Over the 10 months the cumulative saving was 225,111kWh. At 3p/kWh this is a total saving of £6,753 and a total carbon saving of 46,370kg of CO2. Consideration is now being given to the other NATS sites around the UK.
“In April 2015 NATS Facility Management introduced EndoTherm and Glycol into its Prestwick Centre heating system. The results have been impressive, 16% reduction in energy and a CO2 reduction of 46 tonnes.”Facilities Team