Posts filed under ‘Heating’
Update on the Renewable Heat Incentive and Feed-In Tariffs
Update from the Energy Saving Trust on incentives for renewable heat, as well as update on financial support available to larger scale solar-produced electricity
Solar Energy presentation in Ashtead on Weds 2nd Feb 8pm APMH
We were invited by the Ashtead Transition group to join them for an evening of information about solar energy – both solar hot water, and photovoltaics. It was a very useful opportunity to learn more about these solar technologies.
Renewable Energy for your home – Hot Water & Electricity from the Sun
Council grants for improving energy efficiency in the home
Epsom and Ewell Council have a page on the different schemes you can use as an Epsom and Ewell resident to get support for home improvements such as insulation.
http://www.epsom-ewell.gov.uk/EEBC/Environment/Energy/default.htm
One of the schemes is a government funded scheme called Gleen who can be contacted on 0800 652 3163. The services they offer include:
Funding runs out end of March 2011 so call them soon over the next few months to make sure you don’t miss out.
Heating in the home
What to do first
Before making any changes to your heating system it is important to make sure you have the right amount of insulation – if you have too little insulation, you will be using more energy than you need to to heat your home, and spending more than you need to.
Types of heating
There are many types of heating available, and many people have a mix of heating sources. Boilers account for about 60% of all domestic CO2 emissions. Here are some of the most common types of heating:
- Gas central heating with radiators
- Gas central heating with underfloor pipes
- Gas warm air heating
- LPG central heating with radiators
- LPG central heating with underfloor pipes
- Oil-fired central heating with radiators
- Oil-fired central heating with radiators
- Solid fuel central heating with radiators
- Solid fuel central heating with underfloor pipes
- Electric underfloor heating
- Electric warm air heating
- Gas combi (combination) boilers
- LPG combi boilers
- Oil-fired combi boilers
- Gas fires
- Solid fuel fires
- Wood-burning stoves
- Electric fires (fixed or free standing).
Often – but not always – the heating system also provides hot water for sinks, baths, showers etc.
Gas central heating
This is the most common system in the UK, usually providing heat via radiators and also hot water via a hot water storage cylinder. The boiler heats up water for the radiators and also for storage in the hot water tank, for use in sinks etc. Heating controls make sure the heat goes to the right place at the right time and at the right temperature.
Improving your heating system
If your boiler is more than 10 years old or is unreliable, then you should think about replacing it. New boilers are not cheap, but you may be eligible for a grant – you can check your eligibility here. Special offers may also be available from your fuel supplier.
For gas, LPG and oil-fired boilers the most efficient type you can get is a condensing boiler – by law most new gas boilers fitted in England and Wales must now be high efficiency condensing boilers (with a few exceptions depending on suitability. These use more of the heat generated by the boiler to heat the water; as a result, the flue gases are cooler and condense – hence the name. The boiler will need a pipe to a drain outlet (e.g. it may be plumbed into the sink outflow). Condensing boilers are highly efficient, converting 88% of their fuel into heat (compared with 78% for other types) and should reduce heating bills considerably. With the right heating controls, you could save up to 40% on your fuel bill – that’s about £190 – £240 off the average bill.
Combi boilers
Combi (or combination boilers) are a particularly attractive form of heating because they dispense with the need for the hot water cylinder in the airing cupboard, and also the large cold water cistern (“tank”) plus small header cistern in the loft which are otherwise needed in conventional vented heating systems. All the major components are housed in one unit which makes them very convenient to the installer. They are especially suitable for smaller households with undemanding lifestyles. They are less suited to larger households although the very latest models seem more capable than their recent predecessors.
Some points to consider:
- Combis generate hot water as and when it is needed, avoiding running out of it. The hot water is at mains pressure, which is an advantage for showers.
- Standard combis take 40 seconds to heat water and this is a considerable wastage of water. However, slightly more sophisticated combis have a device which restricts the flow of water until it is hot enough to use. Others (storage combis) keep a small reservoir of water permanently hot.
- Standard combis provide maximum pressure through only one tap at a time. If you have two taps running the flow rate diminishes. This can be partly overcome with a high power or a storage combi.
- The flow rate for the appliances in the house is limited by the capacity of the rising main. Flushing a toilet may thus lead to the hot water temperature fluctuating, or even going cold.
- Do not install a combination boiler unless your rising main is sufficiently good – flow rate may not be adequate for washing machines/dishwashers that require a hot feed.
- An airing cupboard is a godsend to some people for the final drying/storage of clothes. A combi dispenses with the cylinder and hence the space needed for it. However, if an airing cupboard is available, it may be possible to keep it warm by installing the boiler within it.
- It is also important to make sure you have up to date and efficient heating controls.
- An immersion heater cannot be used as an emergency backup in case of the boiler failing as there is no cylinder for it to go in.
- Solar heating panels can’t be used with combis as there is no hot water storage tank.
More information about combi boilers can be found here
Solar heating
Solar Water Heating (SWH) is a system for heating water using energy from the sun. Solar energy is collected by a panel, which is connected by pipes to a hot water storage device such as a hot water cylinder. The system can provide almost all of your hot water during the summer months and about 50% year round. It reduces your impact on the environment – the average domestic system reduces carbon dioxide emissions by around 400kg per year, depending on the fuel replaced.
SWH depends on radiation not direct sunlight so it works even on dull days. However, in winter, although a panel can be effective in helping warm your water, you will still need your existing hot water heater to provide most of your water heating needs. You should note that these systems are not designed to work in conjunction with your central heating radiators – they can only heat your water.
However, in the Autumn, Spring and Summer, a solar panel can yield surprising results, often not requiring any support from your boiler. Depending upon your system and how and when you use your hot water, you could find that almost all your needs are met by a SWH panel at these times of the year.
Installation:
- You need either a southerly facing roof or two roofs facing east and west
- The panel usually sits on top of existing tiles/slates
- You can carry out a DIY installation or can use an approved contractor
Cost and maintenance
There are two main types of solar water heating:
- Flat Collectors: A flat collector is basically a piece of copper tube, bent to form a serpentine shape and then soldered to a sheet of copper. The tube and sheet are painted black and are mounted in an insulated box with a suitable glass or plastic lid.
- Vacuum Tube Collectors: An alternative is a vacuum tube collector that contains a heat sensitive liquid. Vacuum tube collectors are more expensive than flat collectors but are more effective in winter.
The typical installation cost for a domestic flat plate collector system is £2,000 – £3,000. Evacuated tube systems will cost £3,500 – £4,500.
You can also fit or build the system yourself. It may be cheaper but will take longer and you’ll need a certain level of skill. However, DIY jobs are not eligible for grant funding.
Solar hot water systems generally come with a 10-year warranty and require very little maintenance. A yearly check by the householder and a more detailed check by a professional installer every 3-5 years should be sufficient (consult your system supplier for exact maintenance requirements).
You may be eligible for a grant from the Low Carbon Buildings Programme – see http://www.lowcarbonbuildings.org.uk/how/householders/
Links
You can find out more about solar water heating at:
http://www.est.org.uk/myhome/generating/types/solarwater/
Heating Controls
Good heating controls suited to your heating type are essential so that you get the right amount of heat when and where you want it; inefficient controls will waste energy and make your system more expensive to run.
A properly controlled system should have:
- A programmer.
- A room thermostat.
- A programmable room thermostat (instead of separate programmer and room thermostat).
- A cylinder thermostat (if you have a hot water cylinder).
- Thermostatic Radiator Valves (TRVs).
More advanced controls, such as boiler energy managers, are also available.
Try reducing your thermostat by 1ºC. This can cut up to 10% off heating bills and save energy.
Links
Some useful sites for more information on heating systems are:
