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BSRIA model project - Surrey Sports ParkDecember 2010

Wind-assisted ventilation, a biomass boiler and a proactive approach to energy management makes Surrey University's new sports centre an interesting example of the genre, as James Parker reports.

With the London Olympics but a hop, skip and jump away, sport is the name of the game. Now the budding Olympians of the University of Surrey have a head-start on their competitiors following the opening of the Surrey Sports Park in April 2010.

The building and its amenities have been built on the University's Manor Park site. This was previously the playing fields of the old Varsity Centre, one of two separate sporting complexes owned by the university. The facilities are a vast improvement, with all sports needs located on one site.

The main building is a more discrete edifice compared to some of the more recent additions to the University from the like of Nicholas Grimshaw (the Duke of Kent Building, which is now a landmark on the Guildford Skyline) and Penoyre Prasad (the new Guildford School of Acting, which now acts as a gateway to the campus). The building's green credentials are hinted at with the wave-form roof, through which pop wind-assisted ventilators, and the elevations are part timber-clad.

In layout, the designers have squeezed a lot of functionality into the floor area. On entering the building the nature of the building becomes clear with two show courts for playing squash to one side and a climbing wall extending beyond the entrance foyer.

Leading off left is a corridor to more squash courts, two sports halls and the Surrey Human Performance Institute, another corridor to the right leads to the 50 metre swimming pool with its associated showers and changing rooms. Upstairs adds two dance studios, a gym, bar, two seminar rooms and a concessionary coffee shop.

The facilities have already caught the eye of several sporting organisations. Naturally it is home to the University's sports teams, but it has also attracted Surrey Storm netball team, the Guildford Heat basketball team, and Guildford City Swimming Club to hold their games at the sports park. Harlequins rugby team now also use the pitches and facilities as a training ground, and it has also hosted the majority of the games for this year's Women's Rugby World cup.

Surrey Sports park was built on the University's playing fields, but has brought with it an increase in facilities. A new tennis centre is also planned for the site.

Heating system

The swimming pool justified the choice of a biomass heating system, as biomass boilers perform best when they are able to satisfy a steady high base load.

The 300 kW unit, from the Austrian firm Gilles, runs constantly, supplying the pool heating base load of 120 kW. Less environmentally-friendly are three gas boilers that back up the biomass at times of high demand and when the biomass boiler is under maintenance.

Not only does the building have the right load profile for a biomass boiler, but the client has negotiated a sustainable supply of wood chips as well. No left-over logs from Canada or Europe get burnt here. Instead the fuel is supplied from the Albury Estate a little over five miles away.

Guildford is one of the best towns in the UK for biomass as it is in one of the most densely wooded areas. The Forestry Commission's National Forest Inventory states that the South East has more woodland than any other English region, with twice the coverage of the national average, and Surrey is the most wooded county in England, with 22.4 per cent of its area covered in trees.

No sports centre would be complete without a fully-fitted out gym or fitness centre. This is one of the areas that is mechanically cooled due to the heat generated by the occupants.

Ventilation strategy

The two sports halls are naturally ventilated with the use of Monodraught Windcatcher units. To avoid excess drafts and comply with the standards required for badminton, low flow diffusers have been installed instead of Monodraught's usual eggcrate grilles.

Sceptics may say that there will be problems of overheating during hot weather, but so far this hasn't occurred. No problems were reported during the very warm weather in July 2010. The ventilators are controlled by temperature and CO2 sensors, and are capable of night purging.

The Windcatchers were not part of the original design scheme. Mechanical ventilation was proposed at Stage D, but this was changed to wind-assisted ventilation during consultation between the M&E consultants Van Zyl & De Villiers and the University. This change in design had the benefit of reducing the estimated energy consumption and reducing the space needed for plant.

Other elements of natural ventilation are included in the main thoroughfare, which essentially divides the dry sports facilities on the ground floor from the wet-sports area. Motorised fanlights under control of the BMS have been installed above the main entrance doors. These are matched by vents located above a fire escape at the far end of the full-length corridor.

Some areas require mechanical ventilation and cooling, such as the fitness centre, dance studios, seminar rooms, the bar and the offices, all of which have split air-conditioners. The swimming pool and changing areas are also mechanically ventilated.

The first floor corridors alongside the sports hall bar, has motorised rooflights. The motors burnt out not long after occupation. The cause is unknown.

The air-conditioning units are controlled by the BMS in the gym and seminar rooms. In the seminar rooms there is a degree of occupant control available, if the facilities manager allows. This can be set to either full occupant control, full BMS control, or limited occupant control to a couple of degrees either side of the BMS setpoint. The units are set to be on from 09.00 to 21.00 h, as the use of the rooms is irregular (they are used by the Harlequins rugby team in a rather ad-hoc manner). The intention is to refine the controls once a timetable for the rooms is available.

The office for the sports park is cooled by two split units, one on a local control and one on the BMS. Here the typical 'battle of the sexes' has ensued, with the men wanting the temperature a bit cooler and the women a bit warmer.

Lighting systems

The lighting throughout the building is controlled by a Lutron system. Being a new building, there are elements of the operation that are still to be optimised, and the lighting control is one of these areas. While there was some handover training, the facilities team were not in place at the time.

The system is linked to a dedicated laptop with wi-fi connectivity. This way the facilities staff can walk around the building and adjust the lighting levels and switching as required.

Optimising the lighting could dramatically cut the Centre's energy use. At present there are areas that are both daylit and electrically lit. The facilities team will be able to optimise the lighting once they've been trained in the use of the Lutron system. Some changes to the lighting have been made, for example the squash court lights are generally turned off when not in use. This is controlled from the reception, which has a full view of the main show courts opposite the desk.

Many areas are already set up for energy saving, with occupancy sensors in changing rooms and stairwells - areas that are likely to have variable occupation. There is also no need to worry about daylighting in these areas, as they are all internal spaces.

The lighting levels in the pool hall are controlled on lux levels, although at present the Lutron control switches the lights on in a random pattern to achieve a desired lighting level. While it achieves the aim, it does look a bit odd.

The mysterious greywater tank in the swimming pool plantroom. Despite its labelling, the building has no greywater and the tank is mains-connected.

Water issues

A building with a swimming pool gets through a lot of water, so there is the usual water treatment plant required to replenish the pool and keep the pool water clean.

The one thing that captures the eye is a storage vessel explicitly labelled 'greywater tank', which appears to be mains-fed. No-one on site can recall whether the sports centre lost its greywater recovery during design but retained the tank. Certainly there are a lot of areas where water can be collected, such as the showers.

A more cost-effective option, given the large expanse of roof, would have been rainwater harvesting. The sports centre has a high rate of water use for irrigating its playing fields.

Facilities management

The University of Surrey takes its facilities management seriously. The team studied the initial energy data in order to determine whether the building was operating efficiently. By comparing the centre's energy use with that of the K2 leisure centre in Crawley, a similar building in terms of facilities and size, the facilities team identified a significant difference in electricity use. Further investigation narrowed the problem down to the electricity meter, which had been reading double.

EDF has rectified the meter, but it highlights how important it is to calibrate and check all energy consuming items, even fit-and-forget items like mains meters. A good clue is if the sub-meters don't total up to match the main meter reading. That is usually a good clue that something is amiss.

One area that has posed a problem is the old issue of facilities management versus operational management. The facilities team are keen to fit a pool cover to allow for the potential of up to 30 per cent energy savings. However, there is resistance from the operational team, saying it will take too long to put it on and take it off each day.

Swimming pool covers save energy by reducing the evaporation of the pool water, keeping more heat in the water and reducing the amount of ventilation required to maintain the humidity levels in the pool hall. This has the additional effect of reducing the condensation and the pool structure's exposure to the aggressive chlorine-rich environment, potentially extending the life of the building and reducing maintenance costs.

BSRIA has been retained by the Unversity of Surrey to assist with energy analysis and to advise of improvements to the energy management strategies. BSRIA will report back in 2012 with a 12-month review of the centre's energy use.

James Parker MSc BEng (Hons) AMIMechE is a research engineer and BREEAM Assessor with BSRIA:

T: 01344 465600