The way in which your house is heated will obviously affect the way you heat the bathroom, but you can vary the heating arrangements to suit the special needs of bathing. Firstly, you will need some general background heat in order to keep the structure and fittings at a reasonable temperature all the time. Secondly, you will probably need some supplementary heat to boost the temperature when the room is in use. Thirdly, you may need a special heat source to cope with condensation and heavy steaming up of mirrors. Many modern central heating systems have come to rely too much on warm air as the main means of providing comfort. Unfortunately, extremely high air temperatures are needed by some more chilly people to achieve bodily comfort. As a result, many domestic and office buildings provide conditions of overheated discomfort for many of the occupants.
A balance of radiant heat and convected warm air is generally a better arrangement and, strangely enough, the old-fashioned hot water radiator system achieves quite a satisfactory balance. In the bathroom the heated towel rail is in effect a small radiator and when, as was customary, it is connected to the domestic hot water circuit rather than the central heating circuit, it provides warmth to the bathroom and the towels, and, what is most important, the bath mat all through the summer months as well as the winter at a cost. It is arguable, however, whether alternative methods are any more economical. The economy is best achieved by a judicious use of the thermostat and the time clock.
Other methods exist, of course, but it is certainly advisable to have some sort of background heat, perhaps off the central heating circuit with a booster in the form of an infra-red heater or a warm air blower; this latter, if mounted over the mirror, can remedy any condensation on the glass. There are a combined warm air heater and overhead light unit on the market which is extremely effective when used in this way. Infra-red heaters, although effective, are visually extremely difficult to incorporate into a bathroom. It is possible to obtain finned hot water pipes that act as miniature radiators when connected to a central heating system and can be concealed behind fascias.
There are many types of flat panel radiator and it is worth remembering that these need not necessarily be mounted in exactly the way your local plumber may suggest. Vertical mounting up a wall is one possible arrangement where space is limited, or they can be sited along the side of the bath. Individual tubular electric heaters are cheap to buy; thermostatically controlled, oil-filled radiators and towel rails are more expensive but are worth considering, particularly as they are relatively economical to run.
Ideally, the waste heat from the fridge or freezer could be taken advantage of, and no better use could be found for this than as background heat for a bathroom. Any appliance of this sort operates by dissipating waste heat into the atmosphere and a back-to-back arrangement of freezer and bathroom would be a very satisfying solution.