Cylinders- An integral part of an efficient and cost-saving heating system.

Choosing the right cylinder has a role to play in saving energy, says Dad Parker of Glow-worm.

 

  According to the Energy Saving Trust (EST), gas central heating systems that are more than 15 years old are not as efficient as they should be. It may be that a customer really needs to make the decision to upgrade to a new state-of-the-art energy-efficient system rather than continue to apply repeated short term and cumulatively expensive fixes to an inefficient system.
  Changing to a high-efficiency system with just some of the fuel-saving products - such as controls and a more efficient and correctly sized cylinder - are acknowledged to be able to cut heating bills by up to one-third.
  A sensible and proven money-saving and environmentally sound move is to reduce heat loss from the hot water cylinder. An upgrade from an old copper vented cylinder to a modern, unvented high-performance, low-heat-loss version will certainly pay dividends in saving energy.

  In the old days, you had a copper cylinder in the airing cupboard, which got so hot you could burn your hand on it. Then came the great idea of clothing it in a red insulation jacket but that didn't really do much to solve the problem.
  With new cylinders, you put your hand on the outside and they are cold, which means they are far more energy efficient. Today's quality-manufactured cylinders prevent the energy being used to heat the hot water being lost in the airing cupboard. Less heat lost by the cylinder also means that less energy is needed to reheat the cylinder the next time the hot water is programmed on.
  Nowadays manufacturers are producing cylinders with excellent insulation that achieve heat loss ass low as 1kWh/24hrs (120 litres) and a high recovery heating coil that reheats the cylinder in less than 20 minutes.

  A bit of research and preparation also goes a long way - the property's heat loss must be calculated to ensure installation of the right output of boiler and cylinder size.
  More central heating mishaps are due to oversized or undersized equipment being installed. In fact, this is a key requirement under BS 6798: 2009 Specification for installation and maintenance of gas-fired boilers of rated input not exceeding 70kW net.

  The new standard specifies requirements for the selection, installation, inspection, commissioning and maintenance of gas-fired boilers for central heating and other purposes, which have a total rated heat input not exceeding 70kW, based on net calorific value.

  According to the HHIC (Heating and Hot Water Industry Council), if an older boiler is being replaced with a new, high-efficiency one then Building Regulations say the rest of the system should be upgraded so the cylinder complies with BS 1566: 2002 Copper indirect cylinders for domestic purposes. Open vented copper cylinders. Requirements and test methods. An important point here to remember is that, even if an open vent cylinder does comply with standards, there are still many energy-saving benefits in replacing it with an unvented one due to better hot water delivery and insulation.

Controls

• One small but really important cost-saving consideration is the inclusion of weather compensation controls in the installation. A weather compensation system can be created by teaming an outdoor sensor with the boiler and its controls. This arrangement will give increased levels of system comfort and increased efficiencies.
• Weather Compensation measures the temperature outside the propertyand adjusts the flow temperature to the radiators accordingly. The colder the outdoor temperature, the hotter the flow temperature will be.
• The effect is that the flow temperature adjusts the output of the radiators to meet the actual heat demand of the property. The lower flow temperature also ensures that the boiler operates more efficiently. Weather compensation may sound complicated but it really is simple to install.
• In terms of choice of cylinder, engineers should look for a supplier with a decent range, from 115 litres to 300 litres, and each one should be able to work with any boiler in open vented and sealed heating systems,
  The cylinders should be robust and built to last, preferably manufactured from high-grade stainless steel, with laser welded seams and a guarantee against perforation of the steel shell. The chosen cylinder should have excellent insulation and achieve low heat loss.
• Also important is a high recovery heating coil that reheats the cylinder quickly and meets central heating system specification, as defined in Domestic Heating Compliance Guide for England and Wales. Other requirements may apply in other regions. Low or no maintenance is another consideration.
• Engineers should also look for cylinders that have an auxiliary back-up electric immersion heater, operating thermostat and energy cut-out.
  
  A good knowledge of current legislation and guidelines is the key to ensuring a good choice and application of a hot water cylinder into an efficient hot water system. This, in turn, ensures a happy customer.

 

Source - Gas Safe Register

 

Posted Date: 04th Jun 2010