Most of us prefer to believe that global warming is largely affected by the gaseous and chemical outpourings from modern industry, and as such, is something that we as individuals have little power to change. In fact, the energy used by UK homes is now the biggest portion in total national energy use. To try to avert the quickening global crisis, homeowners can and should take steps to prevent energy loss and heat wastage from their properties.
In response to the global warming situation and the subsequent Kyoto treaty to reduce carbon emissions, additions to the Building Regulations were introduced in April 2005 to prevent energy losses from new and renovated properties. The Part L Regulations introduce building legislation that aims to reduce energy consumption by 25%.
Manufacturers of heating products and systems are now creating energy efficient goods in line with these new regulations, and there are also an increasing number of eco-friendly systems being developed that try to utilise naturally occurring environmental resources.
Types of Boiler
Boilers can produce as much as 60% of all domestic CO²;, so consequently the Part L Building Regulations now state that practically all new and replaced boilers should have a SEDBUK rating of A or B.SEDBUK is the acronym for Seasonal Efficiency of Domestic Boilers in the UK. The rating it gives is an expression of its effectiveness in converting fuel into heat. A boilers are 90% or above efficient, while B boilers offer 86% or more. The rating runs from A to G, but only A and B carry the energy saving recommended logo.
High efficiency condensing boilers fall into these categories, as they convert 88% or more of their fuel into heat. With good heating controls, your fuel bill can be reduced by 40%, meaning £150 - £180 off your bill. Heating controls allow for effective management of your boiler use so that you can create different heat in different rooms and set a heating timer.
Conventional design boilers lose heat energy with the products of combustion. It causes convection to emit the exhaust through a flue, but is otherwise wasted energy. Condensing boilers contain a heat exchanger that pre-heats water in the boiler. Water vapour is produced that condenses back into liquid form and releases latent heat. Effectively, in a high efficiency boiler, the heat produced during combustion is largely absorbed by the heat exchanger into the heating water with little wastage and less fuel used.
High efficiency condensing boiler will cost in the region of £400 - £700.
A well insulated home will keep plenty of warmth inside and unwanted cold on the outside. Good insulation means that you will use less heating as your home will be able to keep itself fairly warm. It also helps to stabilise the property's temperature during summer, keeping out the intense heat that can created by the sun. A vast percentage of your home's heat can be lost through the loft and walls. Further insulation measures can be added on tank and pipe insulation, draught proofing and double glazing.
Cavity wall insulation is a relatively expensive home improvement measure, but it is quick and clean to carry out. Although it costs about £4.70 per square metre of wall, (around £479 for a three bed semi); you may be eligible for a £200 grant from the Energy Saving Trust. It is also argued to save you about £100 on heating bills.
Several holes are drilled into the external wall, and the insulation is blown/injected into the cavity that exists between the inner and outer brickwork leaves. The holes are then re-sealed with little suggestion that work has taken place. The insulation combines with the still air and creates a barrier to energy escaping; cavity wall insulation will help keep your home cool in summer as well as warm in winter.
Standard loft insulation can be self-installed, but should be to a depth of 270mm to achieve maximum insulation. Again, it helps to keep generated heat within the home and stabilises heat during hotter summer months.
Fibreglass matting is purchased in rolls 400mm wide, and can be lain out quite easily (with gloves and a dust mask on) by rolling it across the loft. Loose fill insulation materials can be bought and installed in a DIY version or be professionally installed. For home insulation, mineral fibreglass or vermiculite are bought in bags and can be poured between joists or in any awkward corners. During specialist installation, a contractor will blow mineral wool or cellulose into the loft.
To prevent losses from your hot water cylinder, a British Standard insulation jacket can be bought from your local DIY store. For maximum benefits, it should be at least 75mm thick to reduce heat loss by about 75%.
Solar water heating systems are used alongside your conventional water heater. Utilising the sun's heat; they can produce nearly all of your required hot water in the summer, thus reducing the energy used and carbon emissions created.
Solar energy is caught by a solar panel which is connected by pipes to a hot water storage cylinder or similar facility. The hot water stored can then be used in domestic hot water supply, caravans, swimming pools and more. The success of the system ultimately depends on: your budget, your location, and your existing water heating system.
How Do You Install Solar Panels?
The solar panels are attached to your roof, and it must be on a 2-4m² of southeast to southwest facing roof receiving direct sunlight for the main part of the day. Ideally it should be on a pitched roof so that it is on a good angle. A standard central heating pump will force water through a coiled pipe within the solar panel, this is heated by the sun and then flows down through a lower coil in the hot water cylinder. The hot water in the coil consequently heats the water in the cylinder and the water is then sent back by the pump to the solar panel.
The system's controller box constantly measures the panel temperature against that of the hot water cylinder. The pump is switched on when the panel water temperature is higher than that of the cylinder. At any time when your hot water cylinder is adequately hot, the boiler will stay switched off thus saving fuel and money. It should be noted that some combi boilers are not suited to solar heating systems.
Despite most people's worries, solar panelling responds to the sun's radiation, not the sunshine, so it works even on overcast days. Inevitably however, it is most effective during the summer, and will need the greatest amount of back up from your existing boiler during the grey winter days. Be aware however, that solar water heating is designed only for water heating, not radiators.
How Much Solar Energy Costs
For a domestic flat plate solar collector the average amount is £2000 - £3000. More complex evacuated tube systems are in the region of £3500 - £4500. There is usually a ten year guarantee attached, and once installed, systems require little maintenance.
There are DIY systems costing from £1000 - £2000 that you can try yourself. It is a project for a more experienced handyman however, and you should expect it to be a lengthier process. Self-installed systems are also exempt from grant funding.
Ground Source Heat Pumps
Also known as geothermal heat pumps, these rely on the earth as a natural heat source. The earth is a giant solar collector that absorbs the sun's radiation, resulting in a temperature of 11 to 13°C a few metres below the earth's surface in the UK. In winter, of course, this is a higher temperature than above ground. The purpose of the ground source heat pump is to extract this heat and transfer it into your property.
During the summer, the heat source becomes a cooling source as below ground is cooler than the surface, and so the procedure is reversed. While the heat pump does involve electricity, 3 - 4 units of heat are produced for every unit of electricity used. If you are still concerned about the use of electricity, you can switch to a green electricity supplier.
Heat pumps combine three main elements:Ground loop - The loop is made up of lengths of pipe that are buried underground in a borehole or in a horizontal trench. The pipe is a closed circuit containing water and antifreeze that is pumped around absorbing the ground's heat.Heat pump - The heat pump itself comprises three significant parts.
Heat distribution system
- An evaporator that takes heat from the water in the ground loop.
- A compressor that moves the refrigerant around the heat pump and compresses it to the temperature required for heat distribution.
- A condenser that heats the hot water tank feeding the distribution system.
- However you choose to heat your home. Either with underfloor heating or radiators, and maybe some hot water storage facilities. Underfloor is often a recommended combination with ground source heat pumps as it works well at a lower temperature.
Ground space is dug for the ground loop that is either a borehole, a straight horizontal or a spiral horizontal shape. For a spiral horizontal insertion a trench measuring 10m will be required to provide room for 1kw of loop. Straight horizontal trenches go 1-2 metres deep and although they are cheaper than boreholes they inevitably take up more land space. Coiled piping in horizontal trenches is however more effective than straight piping.
Boreholes are drilled down to anywhere from 15 - 100 metres. The initial installation expense is higher than for horizontal trenches, but boreholes have the advantage of higher ground temperatures.
Before you decide to install a geothermal heat pump, there are several areas you should investigate to ensure maximum effectiveness and whether it will suit your property:
Cost of Ground Source Heat Pumps
- Climate - what heating and cooling demands will there be?
- Temperature of the ground heat source and heat distribution system
- Energy consumption by the pumps and controls
- Technical standard of the heat pump
- Size of the heat pump required to meet your heat demands
A standard 8kw system is around £6400 - £9600, not including the distribution system. The price will vary depending on the property and on the location. Ground source heat pumps are not yet eligible for grants.
As for the running expenses, the ground source heat pump is measured by the Coefficient of Performance (CoP). It is an expression of units of heat output for each unit of electricity used to drive the compressor and pump for the ground loop. CoP ratings range from 2.5 - 4, with 4 being more for underfloor heating as it works at low temperatures.
With a CoP rating of 3-4, ground source heat pumps can heat space cheaper than oil, LPG or electric storage heaters. However, it is more expensive than mains gas.
Biomass is the collective name for many types of organic waste matter of recent origin. It involves all things animal, vegetable and mineral; including crop stalks, chicken and pig waste, lawn cuttings, wood pallets and construction waste. Unlike the fossil fuel process, the CO² emitted from biomass generation is counterbalanced by that which is absorbed during the fuel's production. It is a carbon neutral process.
How Biomass Energy is Used?
Biomass is used to heat properties in two ways: through stoves or boilers.
Stoves can be fed by logs or pellets, but only pellets are suited for automatic feeds; the more expensive option. While they are generally stand alone space heaters, some models can have a back boiler addition for water heating. They offer 6-12kw in heat output. Additional features available on some top range stoves include low pressure detection that prevents it from working in the instance of a leak.
Boilers are connected to the central heating and hot water, and can be fed by logs, pellets or chips. Their output capacity is often more than 15kw. Some boiler designs combine with hot water energy storage or an accumulator tank, storing water up to 90°C. This separates further the heat supply from the combustion of fuel.
If you are considering a biomass heating installation, do not forget that it must comply with safety and Building Regulations (Part J). The vent material must be specifically for wood fuel applications, and the stove must allow for adequate air movement. Check the Smokeless Zone regulations, where under the Clean Air Act wood can only be burnt in certain cases.
How Much Biomass Energy Costs
In the UK, wood fuel can be cheaper than fossil fuels. As for the equipment; stand alone stoves of a size sufficient for space heating will cost £1500 - £3000 with installation. The price of your boiler will depend upon the fuel used. As an example; to heat a three bedroom semi a boiler size of 20kw will be required. A pellet boiler of this size is around £5000 with flue, commissioning and installation.