Aug 11, 2005 - 4524.39.2 Unvented portable space heatersaUnvented portable space heater as used herein shall mean a nonflue connected selfcontained self supporting oilfueled heating appliance equipped with an integral reservoir designed to be carried from one room to anotherbOil as used herein shall ...
Unvented Hot Water Cylinders - Benefits Unvented Cylinders (or pressurised tanks) are not vented by an external body, but rather use a pressurised system to move the domestic hot water. Unvented cylinders therefore use the water mains pressure ensuring sufficient pressure of hot water even in higher floors and without the need for a header tank in the loft. Benefits of Unvented Cylinders: Higher hot water flow rates – unvented cylinders offer higher pressure for the shower, bath, kitchen etc. Freeing up space in the loft – unvented cylinder removed the need for header/feeder tank Flexible installation location – unvented cylinder can be installed anywhere in the house, for example in the garage (freeing up space in the airing cupboard) Quieter mains pressure system – as unvented does not require external feeder tanks, there is no noisy cistern in the loft No frozen pipes in the loft – unvented cylinders mean there are no tanks or pipes exposed to freezing temperatures in the loft. Unvented tanks are simple to install Unvented cylinders are engineered to have a long lifetime, which ensures good value for money Un-vented hot water heating systems | | | | When an un-vented hot water system is installed both the hot and the cold water supplies within the dwelling, deliver water at the taps or shower outlet at mains water pressure. Cold water from the mains is delivered to the base of the cylinder, the water is heated, then when a tap or shower is turned on the mains water pressure pushes the hot water out. | | | | | To allow the water that is heated in the cylinder to expand as it is heated, an internal or external expansion vessel is used; a pressure relief valve is also fitted should the vessel fail. An un-vented hot water storage cylinder can be heated directly via an immersion heater or indirectly by most heating systems providing it is not a solid fuel burning appliance They are ideal where high performance is required or in multi story properties where it would be difficult to gain the necessary head of water via a cold water storage tank to feed taps on the upper floors. | | | | | | |
Advantages Balanced pressures at hot and cold taps. High performance showering throughout the house. High pressure and hence flow rate of hot water. Fast filling baths. Potable (drinking) water at all taps. No cold water storage therefore no contamination. Quicker to install Quiet running Fast recovery (typical 15-20 mins for 125L) No fear of frozen loft pipes | Disadvantages No storage back up if mains water fails. Poor mains water pressure will cause poor performance. Need for discharge pipe (overflow) Requires high level of maintenance |
Searched by KNS BUILDING & MAINTENANCE LTD | 
