Lake Taupo, Hilton Hotel Case Study
Lake Taupo, Hilton Hotel
The hydronic consultant for this project specified the John Guest energy saver 10mm manifold system to satisfy the clients desire for a system that would not compromise flow but save water and energy consumption at the same time.
This is achieved by limiting the volume of water stored in the supply lines to each point of use, this in turn reduces the dead leg of cold water which has to be pulled through, before hot water is delivered to the tap. The savings are two fold, as well as the waste water issue, less energy is wasted due to the reduced volume in the arrested dead leg after the tap is closed.
All showers, hand basins and bench taps were supplied in this manner and the bath mixers were supplied from a 15mm adaptor tee pushed into the back of the manifold to give the extra flow required at this outlet.
This system has been used successfully in the UK and Europe for many years on thousands of installations, the john Guest 10mm rocket manifold has been in production since 2002 and was recently remodelled to give even higher flow rates, it is also used extensively in the heating industry to supply hot water to radiator panels.
- Reduced size of holes drilled in studwork
- The elimination of branch line fittings buried behind wall linings
- Visual inspection time reduced and made easier
- Field trials carried out at the Hilton Hotel have produced the following results The 22mm supply lines to both the hot and cold manifolds were pressure limited to 350Kpa
- The 10mm supply lines from the manifold to the points of use were limited to 15 Linear Metres in length.
- Water flow rates at the shower heads were recorded at 8 Litres per minute for both hot and cold ports separately.
- Mixed water at the shower rose at a reasonable showering temperature was recorded at 13 Litres per minute.
- Very little difference in operating flow rate was noted when either the WC or hand basin was used during the test.
- Changes to the water regulations make the use of 10mm supply lines for mains pressure hot water systems an acceptable solution to reduce dead leg volumes to a minimum.