Book - School of Science and Technology

Electrical off-peak storage systems 97Fuel/Energy SourceSolid Liquid Gaseous ElectricalAnthracite Coal Peat Wood Public Supply Bottled On Peak Off PeakOpen FireClosed StovePrimarily RadiantPrimarily ConvectiveLuminousElementsHigh Temp.High Temp. TubesPanels Radiators Convectors FanHeatersInfra-red Natural ForcedLow Temp. TubesHeated Floors Heated Ceilings Storage RadiatorsOil StovesFan HeatersFigure 4.1 Categories of direct heating systemsCondensation ± a warningWhere a liquid or a gaseous fuel is used to provide an energy supply to a direct system ofany description, it is important to appreciate that all equipment does not necessarilyprovide for the discharge of the products of combustion to outside the building. Where noflue is incorporated for this purpose, there will be a significant emission of water vapourto the heated space, dependent upon the type of fuel and this will in all probability lead tocondensation on windows and cold walls. The data listed in Table 4.2 show the magnitudeof this problem.Electrical off-peak storage systemsIt seems open to question whether systems of this type fall within either of the definitionsgiven previously and thus whether they may be described properly as either direct orindirect.Since discussion of the techniques used in designs for heating a space using energyoutput from a thermal store, charged some hours previously, deserves a chapter to itself, itis not proposed to include any further mention here.