Walton Hall near Wakefield in South Yorkshire, once the home of the extraordinary traveller, naturalist and eccentric Charles Waterton, is everyone's dream country house. Set in a wide swathe of parkland (the world's first nature reserve in Waterton's day, now partly taken up be an 18 hole golf course), the early 19th Century house is built on a man made island in a 26 acre lake with the only access from the mainland by an elegant cast iron foot bridge. It is now part of the luxurious Waterton Park Hotel and the beauty and traditional qualities of Walton Hall are complemented by the addition of a modern extension to the rear housing a 39,000 gallon swimming pool and leisure complex.
Heated swimming pools are notoriously expensive to run and the oil fired system at the hotel was taking up by far the lion's share of an alarming oil bill of around £5,000 per month. The owner and management team at Waterton Park decided it was high time to tackle the problem and they were particularly keen to install in its place an eco-friendly system that would not only save money but also reduce the hotel's Wellington Boot of a carbon footprint. They put the matter in the hands of Barum Construction who in turn called on Retherm Limited, of Stoke-on-Trent, experts in renewable energy systems of all types, to propose the most appropriate heating method for the pool and its surrounds. With a large lake almost on the doorstep what else would one use for a heat source? Retherm designed a system using the latent heat in the water, processed by a NIBE Fighter 1330 60kW heat pump, to supply sufficient hot water for the pool and the rest of the leisure area, plus meeting rooms, a bar and some of the bedrooms in the original Walton Hall building.
The design involved eight 400bmetre loops of MPDE piping "buried" beneath the lake's surface, sufficient to ensure that anglers could not snag them, and held in place by weights.
The liquid within the pipes absorbs heat from the surrounding water and circulates it to the exceptionally powerful NIBE pump (this was the first Fighter 1330 60kW unit to be used in this country) that compresses the warmed water to extract maximum heat. The resultant energy is then passed to a NIBE VPAS 300/450 double-jacketed accumulator tank with highly efficient insulation to retain the heat created. For times of exceptional energy demand the original oil boiler was retained as back up.
Barum Construction carried out the installation in close co-operation with Retherm, who are fully accredited by NIBE Sweden to Level 2 (the highest level awarded), and the whole operation went without a hitch. All the NIBE equipment, manufactured by the parent company in Sweden, was supplied by NIBE Energy Systems Limited, based in Chesterfield. Retherm's estimates with the original design document were for a saving of in the region of £22,000 and, equally important, a carbon saving of around 168 tonnes per annum. These seem if anything conservative for certainly the hotel's monthly oil bill has dropped from £5,000 to £1,500 leaving everybody happy. the hotel owner and management team, the hotel guests and especially those using the beautiful pool with its view over the lake. They can't see the pipes beneath the waves but they can appreciate the warm water they supply.