Flat-Living.co.uk Energy Hot topic: communal boilers
The arguments for improving energy efficiency are well- established and straight-forward; it saves money and reduces CO2 emissions. What is perhaps less well known is how easy it is on many heating systems to improve the energy efficiency at low (or even at no cost) and how big the opportunity for savings is – in some cases as much as 30%. In this article Julian
Miller, Director of energy specialist AEC outlines some of the opportunities and also where funding may also be available to deliver this.
ur focus is on communal or district heating sys- tems, where a number of large commercial boilers are supplying heating and hot water services to a block of flats. Unfortunately this will not apply to flats with individual combi style boilers, which is not to say that savings may not be available in these situations.
O WHAT YOU NEED (AND MAY ALREADY HAVE)
Firstly a multi boiler system, it is also useful to have a control system that regulates the boiler firing pattern as well as the temperatures at which they are operating, often called a “building energy management system” (BEMS) but ironically normally not managing energy at all! Adequate control systems, if not already in place, do not have to be ruinously expensive. It is also vital to have automatic meter reading (AMR) on your gas
meter, the old saying that “you can’t manage what you can’t measure” holds for energy as much as anything else. Gas AMR is currently the exception, however it is growing and recent “smart metering” legislation will see it rolled out across the country within the next few years. At a simple level AMR will negate the need to ever have an estimated bill again, at a more advanced level this data can be used to profile energy consumption against demand to better understand how well the boilers are operating using a number of analytical techniques.
THE OPPORTUNITY
Even if a BEMS is in place the likelihood is that it has been set up to provide heating and hot water services, but not necessarily efficiently. It is no exaggeration to suggest that as much as 30% savings could be available, we have achieved this on some sites, the reality is that there is no simple rule for savings, but by being able to control systems properly, you should be looking at a minimum of 15%.
TIPS FOR DELIVERING SAVINGS
Heating demand is directly proportional to the outside air temperature, it may sound simplistic to say that the warmer it is outside the less heating you need, but it is true and should also be reflected in the amount of heating (or gas) being used. Above an outside temperature of about 180C there should be no need to heat, but you will still require hot water and this should be reflected in how the boilers are controlled. Demand can also be measured by the temperature differential between boiler flow and return temperatures, a large differential (8-10 degrees) is indicative of good demand, if on the other hand the differential is only 1 –2 degrees (as is often the case) there is little demand. Any decent control system will be able to give you this information. Another key indicator of inefficiency is boilers firing in quick succession; on-off on-off etc. Boilers should be set up so that only
www.flat-living.co.uk 25
as many fire up as are required to meet the necessary demand. So if you have two boilers only one should be firing to begin with, if this is not managing to cope with demand then the next one will, but the first boiler should remain on, if as is often the case both are “chattering” on and off then good control will lead to greater efficiency.
FUNDING OPPORTUNITIES
In 2008 OFGEM set up the Carbon Emissions Reduction Scheme (CERT) whereby the major utility companies are mandated to deliver energy savings in residential properties (including communal blocks). The vast majority of this funding, and there is £millions of it, has been used for cavity wall and loft insulation, with some high efficiency light bulbs thrown in for good measure. OFGEM have however recognised that communal heating systems present a specific opportunity for delivering residential savings and as a result have allowed the optimisation technology and methodology to be included. Such is the CO2 savings opportunity available on many of these systems that the funding may cover all of the costs. In other words free savings!
For further information
www.ofgem.gov.uk
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56