When needs must
Far from replacing like for like, or as near as possible, faced with the need to replace aging R22 equipment a complete rethink of services in a building in Windsor has brought major benefits for comfort and operating costs — Mike Nankivell of Space Airconditioning explains.
Gulliver House in Royal Windsor is perhaps a classic example of a building where replacing its aging R22-based air-conditioning equipment, which because of the approaching R22 phase out was nearing the end of its serviceable life, turned out to be hugely beneficial. This purpose-built 3-storey office block in the centre of Windsor was not originally designed to feature air conditioning, simply having gas-fired wet central heating.
Over a number of years ‘air conditioning’ had been added, starting with an air-handling unit to supply fresh air and extract stale air. Then came mechanical cooling in the form of multiple split systems — all cooling only and all designed to operate with R22 refrigerant. However, none of the ‘systems’ had been effectively integrated, and the heating, cooling and ventilation all operated and were ‘controlled’ independently.
Inevitably the building occupants suffered from truly dysfunctional climate control, and the operating and maintenance costs were high. In addition, being over 15 years old, the air-handling unit and a number of the existing split systems were proving to be unreliable, so the time was right to consider a rethink.
A further factor was that the building’s two conventional gas-fired central-heating boilers had been recommended for replacement.
The client approached Space Airconditioning for advice on how to address the situation. Unaware of the air-conditioning inspections legislation or, indeed, the R22 phase-out deadline, which Space Air explained as part of its survey report, the client soon realised the potential energy-efficiency and running-cost benefits of replacing the existing cooling-only systems and air-handling unit with a modern heat-pump system and heat-recovery ventilation.
Space Air advised the client on various Daikin-based options, recommending that the best long-term solution would be VRV with integrated heat-recovery ventilation and a centralised I Touch controller to provide energy-efficient climate management. Such a system would replace the need for secondary heating and would be sized to suit the current capacity requirements, which were considerably different to those of 15 or more years ago.
Occupancy comfort would be considerably improved, and because of energy efficiency and technology advancements both operating and maintenance costs greatly reduced.
To complete the proposal a Daikin Altherma air-to-water heat pump was recommended to provide heating for the stairwells and the required hot-water services. A significant benefit from this proposal was that the two existing 180 kW gas boilers would no longer be required and could be decommissioned rather than replaced as originally planned.
A further aesthetic and space-saving benefit of the proposal was that the multiple air-cooled condensing units (19 in total) would be replaced by just four outdoor units, all discreetly positioned at the rear of the building.
Daikin VRVIII systems incorporating a mixture of 4-way-blow cassette, ducted and wall-mounted fan-coil units with fully integrated VAM heat-recovery ventilation units were installed by a Space Air approved installation contractor on a floor-by-floor basis to minimise disruption. Much of the work was carried out at times that were least inconvenient to staff.
On completion, the new systems, including the Daikin I-Touch centralised control, were commissioned and staff trained by Space Air technicians, prior to formal hand-over to the client. The systems are subject to an on-going monitoring programme and will be inspected annually as part of Space Air’s ‘soft landings’ 5-year warranty programme. Already the client has reported a substantial reduction in operating costs — and no gas bills.
The original plant room that housed the air-handling unit and gas boilers will eventually be converted into useful storage — another bonus!
Following the success of this project Space Air has supplied Daikin equipment for a second building in London which had similar issues and has recently secured a third order for another building that the same client is refurbishing.
Mike Nankivell is marketing and business development director at Space Airconditioning.