Water heaters are generally fueled by either natural gas or electricity; however there are some units on the market using LPG and especially for caravan applications there are units that use butane or propane in gas cylinders.
There are single point and multipoint heaters, the difference simply being whether hot water is supplied to one point or to a number of points in the accommodation. Regardless of this the economics of running a unit is governed only by how much hot water you use, the temperature of the water and the fuel used to heat it. The initial cost of the unit is also important, and they vary from £ 100 to £ 1000 depending on their application. To sensibly compare the running costs of various fuel types the graph below show the costs by assuming that the same energy is used to heat the water for the year in a house (All fossil fuel systems are assumed to be 90% efficient). The number used is 5000kWh, which is the average in the UK.
The difference between the cost of electrically heating and gas heating is huge, and careful consideration should be made before deciding to buy an electric water heater. Electrical water heaters are usually cheaper but the price difference will probably pay for itself in running cost savings in a year. You may consider solar water heating but the numbers do not stack up, please have a look at this article.
| Solar Hot Water... |
Clearly gas cylinders are very expensive but there is little choice in a caravan, apart from staying in a hotel instead!
