Three Andrews SUPAflo instantaneous commercial water heaters linked with three ST storage vessels are supplying all the hot water requirements for the recently constructed Arora International hotel, situated close to Heathrow Airport.
These direct gas-fired units serve all hot water outlets in the hotel's 323 en suite bedrooms, restaurant kitchens, public toilet areas and the launderette. The Arora's guest profile is unusual in that British Airways has concluded a long term contract, reserving the hotel for use by its cabin crew and for other staff accommodation requirements associated with training courses and conferences.
This means that the Arora does not conform to the normal daily peaks in hot water usage experienced by hotels generally and is in constant use throughout the year.
Peter White of BWP plc, the consultants responsible for this project, who specified the Andrews equipment remembers, "Initially, serious consideration was given to a plate heat exchanger option. However, the results of a value engineering analysis and report carried out by Andrews showed how, in this instance, the independent direct fired approach would be more energy efficient and cost effective using the particular Supa-Flo models proposed.
High efficiency and operating reliability were also important factors influencing the decision. In other installations where we have used Andrews Supa-Flo units they have proved to be of high quality, giving a reasonable life with low maintenance."
By this time the nature of the project had changed into a "design and construct" contract, executed by NG Bailey from their base at Uxbridge.
Their Project Manager, Howard Taylor, recounts, "Further savings were made by setting up the three Supa-Flos to operate as one block of heaters serving all areas. This meant that the "redundancy" it is necessary to build into any system did not need to be triplicated. This independent solution also means the central heating boilers do not need to be oversized to cover the peaks of hot water demand, saving on both capital cost and running expenses.
The whole system design was based on energy efficiency considerations maximised by the SUPAflos facility to interface with BEMS systems. With a fan-assisted flue being a standard feature it also offers the flexibility in siting needed for this basement plant room."
The largest of 7 models in the R2200 range was specified each providing a maximum heat output of 328 kW, recovering 6332 litres/hr through a temperature rise of 44ºC. A total of 900 litres hot water storage is maintained by the three Andrews ST storage vessels.
Using a two stage atmospheric burner, the R2200 range combines the latest technology for improved efficiency with low Nox and CO2 emissions.