Book - School of Science and Technology

Boiler houses ± size and location 267Room sealed casingProducts ofcombustion1m MinimumConnectorboxCap to flueAir inlet toannulusFlashingRoofCombustionairS EDuctFlueRoomsealedcasingBoilerAir duct(a)(b)Figure 10.5 Balanced flues for boilers: (a) horizontal; (b) verticalwords, when selecting the boiler power for such a combined system, it may not benecessary to add the whole or even a part of the heat exchanger rating to that of theheating system. This approach is not valid, of course, where a very large hot water loadoccurs in a building having a small heating load, e.g. for a large kitchen or laundry.(although the converse might possibly apply in these circumstances!)In summer, when the heating plant is not in use, service to the heat exchanger might stillbe dealt with in the case of a single boiler if this were not disproportionately large.Similarly, where a multi-boiler plant is envisaged, it could be that the selection overallwould offer the opportunity to include one boiler which was small enough to be kept inuse during the summer.Boiler houses ± size and locationVarious attempts have been made to provide guidance for provision, in a new building, ofboiler and other plant rooms of adequate size and suitable location. In general terms, it iseasier to suggest that the site should be at the thermal centre of the load than to define thesize in either area or length width.SizeIt is often the case that information in this respect is requested long before adequatedetails of the building structure are available with the result that the required boilercapacity cannot be determined to greater accuracy than plus or minus 25% or more.Furthermore, there are so many types of boiler and kinds of arrangement that advice atthis stage of building development cannot be more than in very general terms. Someboilers are long and narrow; some are short and tall; some are sectional whereas othersare factory packaged with the result that, in that instance, availability of access fordelivery may be a critical factor.