ConfusedAboutEnergy.co.uk

Generally central heating is the most energy and cost efficient way of heating a home, particularly those systems using fuels that are burned in a boiler.  It is also very often one of those areas where you have the least control.  Factors outside of your control may include:-

• Physical space to install equipment
• Local regulations  (e.g. which fuels  can you user?)
• Local infrastructure  (e.g. do you have mains gas?)
• Do you own the property?
• Budget (do you have the cash to “upgrade”)

Regardless of these factors, this section aims to show the main general options to heat your home.  For each one of the options presented there is also enormous choice available, for example, there are an unbelievable 4000 types of gas boiler on the market, with variations in brand, performance, and power output.  The correct model for you will depend on you circumstances and a heating engineer will be more able to advise on this.  You should do some research on the which boilers have the best reputation, this could save you a lot of headaches in the long run, do not just rely on the opinion of the installer, they may sell you junk.

There are two main groups of central heating systems, the more normal wet central heating and less common dry central heating :-

• Wet Central Heating:-  A ‘wet’ systems is where a central boiler heats water which flows around radiators which can also be used to heat your water.  Electricity, Oil, natural Gas, LPG, Coal or Wood can be used as fuels.  There are regular boilers which heat water in a hot water cylinder and there are “combi” boilers which provide instantaneous hot water.  For both of these you can now only buy condensing boilers, which are more energy efficient than their older counterparts.  
• Dry Central Heating:-  Less common are dry central heating systems such as ducted warm air, electrical element heating and electrical storage heaters.  Both air ducting and electrical under floor are typically installed as a property is built or renovated, storage heaters can be installed at any time.  Ducted warm air systems use a large furnace fuelled in a variety of ways to heat the air.

There are other large-scale heating systems heating systems which sit on the boundary between heaters and central heating, examples of these are large cooker/stove systems, ground source heat pumps, and air source heat pumps.  These are covered in another article, please follow the links.

The tables below show the main central heating options, indicating the cost differences for the various different central heating types and old and new boilers.  It is very tricky to do a sensible comparison, so a typical 3 bed semi detached house has been considered and a heat output  energy figure for both heating the house and the water for a full year has been taken to give a direct comparison to how much energy is consumed to deliver that heat and the cost of that energy.  How much energy is actually consumed to deliver this heat output will depend on efficiency considerations of the boiler and the fuel used.  Where possible old /new comparisons have been made to give you an idea of the effect of greater efficiency in new equipment and the amount of time it will take to pay off the investment in a new system.  A good number for the efficiency of an older boiler is about 70%, yours could be a bit better, but some can be only 50% efficient.  70% is a quite optimistic figure for an older boiler.

Whichever you have central heating will probably be the greatest consumer of energy in your house and hence be the largest energy cost, and probably an area you should very carefully consider before investing.  Combi boilers and regular boilers are treated together in the table below, since in terms of energy use the only real difference is hot water and how this is generated and stored.  The cost differences are relatively small.

conclusions