The Manchester based M&E contractor Farebrother Ltd has installed over 100 Honeywell
Kombi 4 throttle and balancing valves for easier and faster commissioning of the domestic hot water system at the new Holywell Community Hospital, an NHS hospital in Wales (operated by Betsi Cadwaladr University Health Board). The low cost valves
ensure a constant supply of hot water to all outlets at the right pressure and also assist in occasional thermal flushing, necessary to inhibit Legionella bacteria.
The Kombi 4 valves are installed in the hot water returns to balance the hot water system. “The valves
balance the system automatically to a preset temperature during commissioning,” explained Richard Parker, Project Engineer with Farebrother Ltd. “It was much faster
and easier than the traditional practice, which was to install lockshield valves throughout the hospital; we would then have had to adjust each valve manually to balance the system, which would have been very time consuming. The Kombi 4 valves also maintain a much more accurate temperature at all hot water outlets.”
Their temperature control dial is set to maintain 53-55 degrees C during normal operation. When water at over 70 degrees C is flushed through the system for thermal disinfection against Legionella, the Honeywell
Kombi 4 valves open automatically to ensure hot water is rapidly distributed in all risers and pipelines, while maintaining the balance. When this process is complete and the water temperature drops, the valves return automatically to their normal control state.
Kombi 4 valves are small, cost less than other auto balancing systems and are easily fitted using DN15 – DN40 (0.5 inch to 1.5 inch) internal or external threads. An optional drainage adaptor provides convenient system drainage.