{"id":7395,"date":"2008-11-12T11:38:46","date_gmt":"2008-11-12T17:38:46","guid":{"rendered":"http:\/\/magic1host.com\/blog\/2008\/11\/12\/pressurized-cylinders-hold-a-bright-future-for-the-uk-hot-water\/"},"modified":"2008-11-12T11:38:46","modified_gmt":"2008-11-12T17:38:46","slug":"pressurized-cylinders-hold-a-bright-future-for-the-uk-hot-water","status":"publish","type":"post","link":"https:\/\/magic1host.com\/blog\/?p=7395","title":{"rendered":"Pressurized Cylinders Hold a Bright Future for the UK Hot Water"},"content":{"rendered":"
by Tal Potishman<\/div>\n

Pressurized hot water storage tanks, also known as unvented cylinders, have seen a remarkable increase in demand since their introduction to the country in the 1980s. They have proven to be highly popular both with the wider population and the plumbing and heating industry in equal measures. Latest results show 2007 was the first year where unvented systems have accounted for 50% of the hot water systems installations in the UK.<\/p>\n

Compare this with pressurized systems which use the pressure of the mains system to provide hot water at convenient pressure levels. As the name suggests, pressurized systems sustain the incoming pressure of the cold water mains (normally around 2-3 bar in most residential areas in the UK). By keeping the system sealed, the hot water is pumped out to the user at the same flow as the cold water that comes out of the cold water tap.<\/p>\n

However, pressurized systems, as the name suggests, are effectively passing the incoming pressure of the mains cold water system into the hot water system. A typical residential area in the UK would have a mains cold water pressure of around 2-3 bar. By keeping the system sealed, unvented systems can sustain this pressure within the hot water loop, providing sufficient pressure in the shower, kitchen or wherever else it is need in the house.<\/p>\n

The sealed nature of the system led to some technological developments that were needed to address issues such as water expansion. As water heats up it expands and increase the volume it occupies. Traditionally this was easily addressed by the feeder tank absorbing any such expansion of the water. For unvented systems, however, a set of safety solutions has been designed to ensure safety is maintained at the highest level while still allowing for reliable and efficient operation.<\/p>\n

UK regulations for unvented cylinders set out a detailed spec of safety measures to ensure all unvented systems sold in the UK meet the minimum level of safety. One of the main measures to deal with water expansion within sealed systems is the introduction of an expansion vessel. Whether external or internal (within the cylinder) an expansion vessel can absorb the expanding volume of water due the increase in the water’s temperature. Expansion vessels vary but most can handle up to ten bars of pressure.<\/p>\n

Another safety measure is the temperature and pressure relief valve. The PT valve is a simple yet smart mechanical valve which senses whether the temperature or the pressure within the cylinder is too high (or is breaching a preset level). At that point the valve opens up to let the extra steam out into the drain, thus immediately reducing the temperature, the pressure and the volume of water in the system.<\/p>\n

The safety checks and valves ensure a safe and reliable hot water system. The Cold water enters the system at mains pressure, keeping the system (which is sealed) at a constant pressure throughout. The water heats up within the cylinder and is then delivered to the user (still at mains pressure). As the hot water is drawn to the user (normally from the top of the cylinder), fresh cold water enters the cylinder (normally from the bottom) to replenish the levels and sustain the pressure.<\/p>\n

There are two main types of unvented cylinders – direct and indirect:<\/p>\n

* Direct cylinders – normally use an electrical heating unit to heat the water. The electrical unit (often referred to as an immersion heater) is immersed within the water inside the cylinder and has a typical heating capacity of 2.5 to 3.6 kW to heat up the water electrically.<\/p>\n

* In-direct cylinders – this set up is based on a heat exchanger. Since the water inside the tank is heated by another medium using the heat exchanger, it is considered to be done indirectly. Typically a boiler is used to heat up water which is then pumped through the heat exchanger where the heat is transferred to the water inside the cylinder.<\/p>\n

Unvented systems have proven to be an improvement on the old hot water systems, offering higher pressure and better performance. With competition helping to improve availability and reduce prices, unvented systems are likely to grow in popularity.<\/p>\n

\n
About the Author:<\/div>\n
Tal Potishman, member of Heating Central, publishes content on home heating<\/a>, plumbers, Hove boilers<\/a>, underfloor heating and solar thermal. He specializes in helping save money by advising on efficient heating.<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Pressurized hot water storage tanks, also known as unvented cylinders, have seen a remarkable increase in demand since their introduction to the country in the 1980s. They have proven to be highly popular both with the wider population and the plumbing and heating industry in equal measures. Latest results show 2007 was the first year where unvented systems have accounted for 50% of the hot water systems installations in the UK.<\/p>\n","protected":false},"author":2624,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12],"tags":[85],"class_list":["post-7395","post","type-post","status-publish","format-standard","hentry","category-home-based-business","tag-home-based-business"],"_links":{"self":[{"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7395","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/2624"}],"replies":[{"embeddable":true,"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=7395"}],"version-history":[{"count":0,"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/7395\/revisions"}],"wp:attachment":[{"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=7395"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=7395"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/magic1host.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=7395"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}