Baxi Commercial has supplied Andrews Water Heaters solar water heating system and a high efficiency, condensing gas-fired water heater to provide domestic hot water at Oswestry Leisure Centre, a new state-of-the-art leisure facility which opened in 2011. The £8 million development replaced the existing 1970’s building, which was becoming increasingly expensive to maintain and the new centre boasts both main and learner pools as well as a sports hall, fitness suite, activities studio and multi-function room. The building was designed to comply with Shropshire Council’s policy on sustainability, incorporating a number of renewable technologies to minimize both carbon footprint and running costs.
The performance specification for the new building’s mechanical services was prepared by consulting engineers, Ramboll, who selected the equipment as part of a series of measures to improve the sustainable credentials of the building, using appropriate renewable technologies. An important component was the Andrews Water Heaters SOLARflo water heating system which includes solar collectors mounted on the main roof. With 90.8% transmission efficiency, 95% absorption efficiency and a low emission loss of only 5%, these collectors transfer maximum heat to a 900 litre, non-corrosive, stainless steel unvented twin-coil cylinder. This, in turn, supplies pre-heated water to a SUPAflo SF66 condensing gas-fired water heater, thereby considerably reducing consumption of natural gas. The SF66 SUPAflo model has an output of 475kW and a recovery rate of 8,130 litres/hour through a temperature rise of 50oC and is linked to
an Andrews SB500 buffer vessel. This system supplies all the domestic hot water for the building, serving 38 showers, 40 wash hand basins, three cleaners’ sinks and two tea room sinks. Integral controls are supplied with the equipment and these are connected to the BMS for time control and monitoring. The BMS also provides overheat, gas safety controls and fire alarm interlocks.
The equipment was installed by Technic Mechanical Services Ltd. Eight solar collectors were mounted on the roof, which has a very low pitch. Consequently, the collectors were specially supplied for the project, having a landscape rather than a portrait format and they were installed using the flat roof mounting kit supplied. The remainder of the equipment, comprising the water heater, buffer storage vessel and solar cylinder, were installed in the first floor plant room, along with the remainder of the SOLARflo package, which also includes solar controls, pump station and expansion vessels. SOLARflo glazed flat plate collectors are Solar Key Mark Approved and, similar to the stainless steel unvented cylinders and evacuated tubes in the Andrews range, carry a 10 year guarantee. A spokesman for the installers commented: “The equipment was selected by the consultant; however, Andrews would be our first choice. Due to site constraints and other factors, there were some installation and commissioning issues but, with advice and assistance from the Andrews’ technical, service and commissioning teams, these were overcome without causing delays.” Matched equipment from a single source, together with the availability of technical advice throughout the installation, is a particular benefit of the Andrews Water Heaters’ product range and after sales service.
Andrews’ SUPAflo water heaters are gas-fired, high efficiency water heaters, capable of supplying large volumes of hot water for a variety of commercial and industrial applications. These are low water content units with a copper or stainless steel finned tube heat exchanger and stainless steel headers and manifold. Suitable for either vented or unvented systems, they operate ‘instantaneously’, providing hot water on demand or, and, as in this case, can be linked with a buffer vessel.
The SF60 KM series of SUPAflo water heaters is the latest addition to Andrews’ SUPAflo range, providing condensing technology with ultra low NOx and CO2 emissions. The units are high efficiency condensing heaters with downward firing blown gas pre-mix water cooled burners that fully modulate between 20% and 100%. The heaters offer a seasonal efficiency of 106.8% at 75/60°C. Units are lightweight with a very small footprint, providing greater siting flexibility. The heat exchanger is constructed with stainless steel fin-tubes and stainless steel header manifolds. All models have a room sealed facility if required. In addition to the standard equipment supplied, units in the SF60 range also come complete with a gas filter and condensate trap and have the facility to control and power their own Bronze UPS primary circulator. A comprehensive control panel indicates all operational and lockout status with full history.