Calculation of heat load – heattechnical calculation – is one of the main tasks when providing housing and industrial buildings (constructions) with heat. Necessary power of system pays off by drawing up heat balance of the warmed room with the calculated temperature of external air which is defined as the average temperature of the coldest five-day period.
1. For each specific area of construction calculated temperature is defined by standards. As outside temperature is subject to significant changes, and loadings within year change. Operational regulation of heatsystem provides change of quantity and temperature of the heat carrier going to the consumer.
2. Thermal power of heating services, its loading, pays off as the sum of all losses (expenses) of warmth for the cold period of year: Qot = Qogr + Qvent ± QbytQogr - heat waste through walls, windows and all external protections. Heat rate through external protections depends on the sizes and design features of the building, quantity of door and window openings and also on material from which the construction is built. Heat rates through external protections are normalized by special construction rules.Qvent – heat rate, external air, necessary on heating, which gets into the room naturally. Usually this indicator depends on design of windows, doors, speed and the direction of wind, the device of ventilation system, outside temperature, tightness of the building, etc. As a rule Qvent makes about 30-40% of all heatlosses of construction and is regulated by Construction Norms and Regulations .Qbyt – household and technology expenses or heat production. This indicator depends on characteristic of the room, its use. At its calculation the number of people who is in the room, the time spent, accommodation in the building is considered. When calculating thermal power of industrial construction are considered as well the technology indicators connected with expenses or with heat production.
3. At the correct calculation of necessary thermal power, loading of the building such system of heat supply at which receipts of warmth and its loss are in the mode, the most comfortable for human life, implementation of any given type of activity by it is projected.