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.
| Various Heaters | Heat pumps... |
The tables below show the main "wet" central heating options, with the most common at the top and the more obscure lower down the table. Storage heater are also included for comparison. The table presents annual running costs for an older boiler, optimistically estimated at 70% efficient and a newer efficient probably fully condensing boiler, estimated at 90% efficient. 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. . 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.
To get a full cost comparison of the various units add the cost of the unit you are considering to the cost off the fuel option over the expected lifetime of the unit.
| Wet Systems (Old Boiler estimated at 70% efficient) | Typical Annual running cost (3 bed semi) Assuming 16,000 kWh per year is output to heat the house or water |
||
| Old System 70% efficient |
New system (condensing) 90% efficient | ||
|
Regular or Combi Boiler |
Standard Electrical | £ 2436 (90%) | £ 2307 (95%) |
| Natural Gas | £ 937 | £ 729 | |
| Heating Oil | £ 1417 | £ 1102 | |
| LPG | £ 1691 | £ 1316 | |
| Coal | £ 891 | £ 693 | |
| Wood Pellets | £ 1143 | £ 889 | |
| Wood Chips | £ 731 | £ 569 | |
| Storage Heaters (not wet) | Economy 7 Electrical Rate | £ 818(90%) | £ 775(95%) |
The 16,000KWh figure includes water heating also. I don't understand the miracle remark, it seems quite the opposite to me.
ii. There is no indication of the value for one of the most important factors in determining the cost of space heating: the temperature at which the space is to be maintained and for how long. Personally, I believe in sweaters but have not yet (two score years +) convinced my family.
iii. Our 4-bedroom (1450 sq ft) home is a 1960 open plan, flat roof structure with a feature fireplace and a central stair well accommodates myself and my wife and a fairly steady stream of house guests. The heating is under-floor, off-peak electric with five separate area controls. There is no heating in place on the first floor, we do use an electric blanket. The off-peak electricity usage for the past four years has been: 10,352; 13,233;13,373; 12,487 kWh. The figure you allot for an average 3-bedroom house (in my George Wimpey days they were generally about 850 - 950 sq ft) is 16,000kWh. So it would appear that some miracle is being achieved. We intend moving to a three-bedroom bungalow and it would be useful to know how to transfer this miraculous environment. Can you help?