Central Heating

Most self builders will use the same plumber for the central heating as they use for the domestic hot water but, there are separate heating engineers. If separate tradesmen or companies are used, then it is important that they liaise with each other and with the electrician.

A heating engineer should be able to take your plans and design the most effective system for your home, taking into account wall thicknesses, insulation values, room sizes and window and door openings.

Standard Heating Systems
The most commonly used and perhaps most cost-effective and efficient system for hot water and central heating is the combination of a boiler and radiators. The efficiency of this partnership is greatly increased by the use of thermostatically controlled radiator valves (TRV's). These allow each room to be set at the required temperature and react to changes in temperature caused by sunshine or other extraneous factors.

Underfloor Heating
Underfloor central heating is increasingly popular with self builders and there are several companies that specialise in these systems. However, in general they all come down to a series of pipe loops set within the floor zone and controlled by room thermostats. While radiator systems work at relatively high temperatures (65/80 degrees), underfloor systems work at relatively lower temperatures (45/55 degrees). This suits the condensing type boilers, which are at their most efficient at the lower temperatures.

It is more expensive to install and it may be more expensive to run but with the increasing popularity of tiled or wooden floors and the fact that it provides a consistent background heat with few cold spots, it is the choice of many. With a relatively slow response time, it is not best suited to those whose occupation of the home is limited to a few hours a day as it is at its most efficient when run on an almost continuous basis, perhaps with a night time set back temperature a few degrees lower than the daytime settings. Intelligent controls can increase the efficiency by anticipating and reacting to changes in the external temperature and translating that to the home's requirement for warmth.

Underfloor central heating works most efficiently within a screeded or solid floor rather than a suspended timber type. A good compromise, therefore, in cost and efficiency terms is the use of underfloor central heating to the ground or solid floors with radiators fitted with TRV's to the upper or suspended timber floors.

Mention should also be made of electric underfloor heating systems, which have relatively low installation costs and can be run at around 1p per hour per square metre. These can be used in combination with radiator heating systems to provide warmth to otherwise cold tiled floors.