HIGH EFFIECENY BOILERS
How can a condensing boiler save my customer money on gas bills?
The high efficiency condensing boiler utilises less gas during operation. Statistically, modern conventional boilers can only offer an efficiency rate of 80%, whereas the rate for condensing boilers is 96%, an essential consideration for consumers. What this means in financial terms is that for every £1 spent, 96p is spent on actual heat. The condensing boiler not only offers this efficiency, but combines it with reduced running costs and value-added performance above conventional boilers. This equates to significant savings on annual gas bills, which will enable your customer to quickly recoup the initial outlay for the boiler and benefit from the extra savings.
Why would my customers want to install a condensing boiler?
We mentioned the cost savings in domestic gas bills, but there is a more far-reaching benefit. In the long term, the high efficiency condensing boiler is designed to protect the environment - as less gas is used, less gas is emitted, which is one of the major causes of environmental pollution. Also, with the introduction of changes to the Building Regulations, it will assure greater compliance to the legislation to conserve energy, which homeowners are increasingly demanding.
SOLAR
How much will it cost to install?
The exact cost will depend on your individual needs. Government subsidies are available and the investment is worthwhile financially as well as ecologically. Our quotation will make it clear what is included and we offer full after-sales service.
How much will I save?
Each panel will save an average of approximately 2000kw hours of power over the year, and provide up to 70% of your domestic hot water needs - but there may be other benefits too, if you use the panels for under-floor heating for example.
How many panels will I need?
Typically just one or two solar panels are ample to supply the needs of an average household. If you have a larger project in mind, please contact us to discuss your requirements.
Which way should the panel face?
It should face roughly south, but anything between southeast and southwest is fine.
What about shade?
Shade from buildings or trees will reduce the amount of solar energy that falls on the panel, so the less shade, the better.
Can I convert my existing system?
A typical system with a hot water tank can be converted by replacing the tank or adding another one.
Do I need planning permission?
Generally for domestic solar panels you do not need planning permission, unless your building is listed, but we advise you to contact your local authority for detailed information.
Can you do the job for me?
Our qualified engineers can carry out the installation, normally in one or two days.
Can I get help to pay for it?
The Government's Low Carbon Building Programme has just been announced. This replaces Clear Skies and the PV Demonstration Programme, and details are available at www.clear-skies.org or from http://www.est.org.uk/housingbuildings/funding/lowcarbonbuildings/faq
Local authorities also offer support and it's a good idea to contact them for additional funding that may be available. See the Grants page for further information. If we haven’t answered your query, or you’d like a consultation or a quotation, please contact us. GROUND SOURCE HEAT PUMPS What is a Ground Source Heating System? A Ground Source Heating System is an electrically powered system that taps the natural heat stored in the earth to heat your home. A heat pump will also heat your domestic hot water, heat your swimming pool and can cool your home in the summer.
GROUND SOURCE/GEOTHERMAL HEAT PUMPS
How does it work?
It simply moves heat energy from one place to another. Your fridge works on the same principle. By using the same process Ground Source Heating Systems remove heat stored in the earth and transfer it into your home. The sun naturally replenishes the heat removed from the ground.
How is the heat transferred from my garden into my home?
The earth has the ability to absorb and store heat from the sun. This heat is extracted from the earth using a ground loop. The ground loop is a continuous closed loop of special pipe buried in your garden. Water is circulated through the buried pipes where it absorbs heat from the surrounding earth. The ground loop is connected to a heat pump inside your home that takes heat out of the circulating water and transfers it into your heating circuit.
How are the loops installed?
The special ground loops are either buried in trenches at a depth of 1 - 2m or installed in bore holes that may be up to 90m deep. Each method is as efficient as the other. Available space determines which method is used.
What is a heat pump and how efficient are they?
A heat pump is a device, which transforms low temperature energy to higher temperature energy using the refrigeration cycle. It is similar in size to a boiler but does not need a flue. A Ground Source Heating System heat pump is three to four times as energy efficient as the most efficient gas or oil boiler. Instead of burning a fuel, and producing the associated emissions that contribute to global warming, they simply move heat that already exists.
What plumbing do I need?
You can use under floor and radiators for heat distribution in your home. If required, comfort cooling can also be provided at an additional cost.
Do all heat pumps give the same performance in terms of energy efficiency?
No. Be sure that you are talking to a company who supply heat pumps that always strive to keep you warm whilst out putting the lowest temperature possible onto your heating system. For example, in the Spring and Autumn your heating system will keep you warm with lower temperature water in it than in the depths of winter. The units we supply do exactly this so enabling maximum energy efficiency year round. A unit which supplies the same temperature water throughout the year (in many cases companies quote 55 °C) will have much lower efficiency over the year, negating any savings claimed.
If the ground loop temperature falls to zero the heat pump will not work as no heat is available?
Not true, zero degrees Celsius is simply the freezing point of water. Absolute zero is the temperature where no heat exists, this is minus 273 degrees Celsius. Therefore even at zero degrees, the heat pump will extract useful heat. Ground source heat pumps will work down to a ground loop temperature of minus 10 degrees Celsius.
Ground source heat pumps are simple, well-proven machines that can provide your entire central heating and hot water requirements. By transferring low-grade heat from a ground heat collector to high-grade heat, very high efficiency (coefficient of performance) can be achieved. This type of heat pump can supply over 4 Kilowatts of heat for each one-Kilowatt consumed.
The compressor, which is driven by an electric motor, compresses the refrigerant to a high temperature, high-pressure gas. This gas then passes into the condenser at about 100 degrees. The water from the radiator system is pumped through the condenser; this is of fully welded stainless steel construction. When this water cools the hot gas, it condenses (changes state from a gas to a liquid thus liberating latent heat). It is this heat that is heating your house. After the condenser, the refrigerant, which is now a liquid passes through an expansion valve, which rapidly drops the pressure and the liquid boils off to become a gas once again. This change of state occurs in the evaporator. In the evaporator, the liquid takes up heat from the circulating cooling medium coming from the energy source in the ground or the bore hole. In this process, the liquid turns to gas (evaporates) under low pressure, which uses heat. (Latent heat of evaporation) This heat is obtained free from the ground or the bore hole. There is a sight glass before the expansion valve so that the amount of refrigerant in the system can be monitored. In normal operation there should be no bubbles in the sight glass. However, bubbles may appear for short periods, mainly on rapid changes between hot water and radiator operation and when the heat pump starts or stops. The sensor of the expansion valve checks constantly that the evaporator is performing at it's optimum, in order to use as much free energy as possible. The gaseous refrigerant then returns to the suction side of the compressor, where it is compressed again. This completes the refrigerant circuit. The control unit constantly monitors the operating pressures and temperatures or the heat pump and will shut down if a fault condition occurs.
How does the free cooling work?
In the summer the heat pump is in operation providing domestic hot water and may be heating your swimming pool. This means that heat is being extracted from the ground loop. By installing a non return valve and two 'T' pieces in the ground loop this cold fluid can be diverted to wall mounted cooling fan coil units. When these fan coil units are in operation they will help to reduce the temperature and relative humidity of the room. This adds heat into the ground loop which is then recovered by the heat pump and transferred into the domestic hot water. This is not to be considered as air conditioning but as comfort cooling that will increase the efficiency of the heat pump and uses minimal energy.
BIOMASS
What is biomass?
Biomass, also known as biofuels or bioenergy, comes from organic matter, either directly from plants or indirectly from industrial, commercial, domestic or agricultural products.
The use of biomass is generally classed as a ‘carbon-neutral’ process. This is because the carbon dioxide released when biomass generates energy is offset by that absorbed by plants during their growth. However, other energy inputs may affect this carbon-neutral balance, for example if fertiliser is used or energy consumed by vehicles harvesting or transporting the biomass to its point of use.
How does it work?
Biomass falls into three main groups:
Dependent resources – includes the by-products and waste generated by agricultural, industrial and commercial processes. This includes forest products, waste wood, straw, slurry, chicken litter and industrial and municipal wastes (e.g. from food processing). For example, for every tonne of wheat harvested, a certain amount of ‘waste’ straw is created. Or for every tree felled to make furniture, a certain percentage cannot be used. These by-products can be used as biomass fuels.
Dedicated energy crops – these are short-rotation crops, such as coppice, miscanthus, willow and poplar, that are grown specifically to generate biomass fuel
Multi-functional crops – these are crops that can be used to create different types of energy. For example, the ears of wheat can be used to create fuel (including bioethanol and biodiesel), while straw can be used to generate electricity.
Biomass can be converted into heat and electricity in a number of ways. Depending on its source, these processes include burning, pyrolysis (the decomposition or transformation of a compound caused by heat), gasification, anaerobic digestion or fermentation.
How much electricity is currently produced from biomass?
In 2003, biomass accounted for 87 per cent of renewable energy sources in the UK – this includes biomass used for both heat and electricity generation. Most of this came from landfill gas (33 per cent) and waste combustion (14 per cent) (source: DTI, ‘UK Energy in Brief’, July 2004). Smaller amounts also came from sewage gas, domestic wood and industrial wood. Electricity produced from biomass accounted for 1.55 per cent of total electricity supply in the same year.
What are the future prospects for this technology?
Biomass has the potential to make a significant contribution to UK heat and energy generation in the future. Limited resources (e.g. landfill gas) may restrict the development of some forms of biomass. Although energy crop-based solutions are difficult to import economically, many biomass feedstocks can be grown in the UK. In some cases, crop yields will need to be improved before the process becomes economic.
Likely areas for development are smaller-scale regional projects, and the promotion of energy crops such as short-rotation coppice.
Europe’s biggest power station, Drax, is testing the use of thousands of tonnes of wood pulped into biomass. If the tests are successful, willow-based biomass could provide 5 per cent of the power station's fuel by 2009 and cut 700,000 tonnes of carbon dioxide emissions.
What effect will this technology have on the environment?
As biomass is carbon-neutral it is good for the environment. Anaerobic digestion schemes can contain the decay process without which, under current disposal practice, methane is released into the atmosphere. The carbon dioxide produced when methane is burned under an anaerobic digestion scheme is absorbed from the atmosphere by growing plants.
A properly-managed anaerobic digestion scheme will contain the intense nutrients found in animal slurries and food residues. These can otherwise leach out in high concentrations and pollute soil and water courses. The by-products from anaerobic digesters can be used as a fertiliser and soil improver. Incombustible materials, such as ash from incineration schemes, also have to be removed, although ash from burning wood fuels can also be used as a fertiliser.
Transporting materials by lorry for biomass plants can cause pollution and disruption, although this can be reduced by transporting them at less disruptive periods.
Combustion chambers used for the burning of biomass need to be well managed to ensure that by-products such as particulates and polyaromatic hydrocarbons cannot escape into the atmosphere.
RAINWATER HARVESTING
What is Rainwater Harvesting?
Rainwater harvesting is a way of saving the rainwater which would normally flow off a roof and down the drain, and using it as piped water to flush toilets and for the garden and car, instead of treated drinking (potable) water.
How does rainwater harvesting work?
A storage tank is fitted to your stormwater drain from your roof, and falling rain enters the tank through a filter which removes leaves and other matter. The storage is usually buried under car parks, a garden or under the drive, and contains a pump which pumps the rainwater to the house where it is piped to the toilets, and to the outside taps.
How much would this save on water bills?
Depending on your normal usage, it can save 30 to 50% for the domestic user and 80% for the commercial user of the treated drinking water from the mains. Having metered water is the best way of appreciating the difference.
How much rainwater does a system collect? This depends on the area and angle of your roof, and your rainfall. Averages of 100,000 litres per household are commonly quoted, much more for large roofed commercial buildings.
What can you use the water for?
Filtered, untreated rainwater should only be used for non- drinking or bathing purposes: toilet flushing, gardens and car washing.
Where is it installed?
The tank should be buried under a car park, landscaped area, garden, patio or drive, with space left for the round access cover. Most systems are designed so that they can accept cars driving over them.
Are there any grants available?
Not for domestic installations yet, although several organisations are petitioning the government for assistance. For commercial installations, there is a tax relief scheme (ECA) for suitable approved equipment on the Water Technology List.
So, why should people buy Rainwater Harvesting systems?
To save on water bills and show they use a precious resource responsibly to make a difference to our environment.
How clean is the water?
The rainwater is filtered as it enters the storage tank, to remove particles and other matter. It is kept in the dark and kept oxygenated to discourage algal growth, and properly designed systems are designed with calming inlets, which ensure that any sediment at the bottom of the tank does not get stirred up. The water is not drinking water fit for humans.
Could rainwater get into my drinking supply?
Not in a properly designed system, the pipework is entirely separate and should be identified as non-potable.
What happens when there is no rain?
When there is a prolonged spell without rain, the water level in the storage tank will fall to a minimum level. At this level, a float switch will open a valve from the normal mains supply and keep the storage tank topped up, until it is filled by rain again. Normal system design should allow up to a week without rain, given normal usage.
Can it be used when there is a hosepipe ban?
Under the current restrictions it is possible to use a hosepipe connected to a rainwater tank, provided that the tank is not connected to a mains water supply. Many people are doing this already by using a water butt.
Do I need to have a water meter?
Not absolutely necessary although, without a water meter your water provider will make the same blanket charge for all your unmetered water usage.
How is the system maintained?
The internal filter should be washed about once a quarter, otherwise maintenance is not needed. The only moving components - pump and float switch have an extremely long life. The system should be designed to overflow a few times a year, to remove and floating matter.
Is Rainwater Harvesting a new idea?
No, collection re-use of rainwater from roofs can be traced back thousands of years in hot, dry countries around the Mediterranean. In continental Europe, some 100,000 are installed annually; Germany has been using and refining the technology since the early 80s.
What regulations govern the installation of a system?
No specific regulations yet govern rainwater harvesting as such, although Building Regulations Part H affect siting of the tank and pipe runs, while Part G refers to internal plumbing.
