Oventrop valves control the heating and domestic hot water systems in two new schools in Surrey

(01/06/2009)

Oventrop valves have been selected to control the heating and domestic hot water systems in two new schools on the same site in Guildford, Surrey. The valves include Oventrop’s Aquastrom T Plus multifunction DHW secondary circulation regulating valves which, as well as providing significant energy savings by controlling temperature and flow in the domestic hot water systems, also facilitates hydronic balancing.

Pond Meadow is a Surrey County Council Special Educational Needs (SEN) school accommodating about 70 mixed students of all ages up to 19 years. The new building is a 300 metre long single storey with an interior plant room and primarily underfloor heating and heat recovery via air handling units for toilets and internal spaces. Oventrop Aquastrom T Plus multifunction valves are fitted in the domestic hot water returns.

Christ’s College, a Church of England aided school, also on the site, replaces the original school which was built in the seventies. The plant room at Christ’s College is on the second of three floors and provides the DHW and LPHW for a mixture of heat recovery air handling units for the classrooms on the perimeter. Larger spaces have underfloor heating with central air handling units on the roof. Oventrop valves, including Aquastrom T Plus, isolation, TRVs and regulating valves have been used throughout.

The Aquastrom T Plus valve is factory preset and functions as a temperature control valve on the DHW return. Once the system is up to temperature the valve throttles down to a residual minimum flow to limit the amount of heat loss in the system and reduce the energy/cost required to raise the return water back up to flow temperature. As soon as the hot water in the return pipe cools to the preset temperature, usually 57ºC, the valve responds by allowing more flow thus eliminating cold dead legs and the risk of Legionella bacteria growth.

As well as temperature balancing, the new valve also provides a hydronic balance of the DHW system and enables automatic system pasteurisation when the HWS generator or stored water temperature is raised to above 70ºC. The valve always provides a residual flow rate to maintain continuous circulation. A manual isolation facility is provided for maintenance purposes. Visible flow regulation is standard and the valve has a preformed insulation shell to minimise heat losses from the valve body. A temperature monitoring facility is standard but if required, this can be removed and replaced with a probe for connection to a BMS.

Oventrop valves were chosen by SES, building services engineers for both schools, to fulfil consulting engineers Atelier Ten’s designs. Main design and build contractor for both schools was Wates Construction, Leatherhead. DSDHA were the architects.

Related categories:  Commercial and offices applications   Energy Conservation   Hot water generation and supply   Valves