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One of the frequent destination cooling or air-conditioning system is to reduce the temperature of the air flow. Natural concomittant temperature drop for removal of moisture from it. For air cooling in the low-temperature refrigeration warehouses in dehumidifi-cation process frost forms on the coil, which is usually undesirable by-product temperature recovery process. In a comfort or industrial air-conditioning, drainage usually desirable goal. This Chapter concentrates on the cooling and dehumidification of the air from 5 to 35C temperature range. .... |
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combustion of fuel (natural gas, coal, oil, and other) and heating electrical resistance are the main sources of energy for heating water in hydraulic systems. Fuel, water heaters, usually made of steel, under strict security standards. One of the ways to classify heaters depending on the working pressure (and, thus, the permissible temperature of the water). Low pressure group provides water at a temperature of about 100C, and therefore at atmospheric pressure or slightly higher. .... |
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the most common heat-conveying media in the field of air conditioning and refrigeration systems of air, water and refrigerants. Focuses on the system of pipelines for water supply, pumps and motivation for a water drain in what is often called hydraulic systems. This site also contains recommendations for selecting the size of the refrigerant pipes. Special procedures required for the design of steam and condensate return, but the question will not be considered. Although steam systems are quite common in industrial units, in air conditioning systems, hot water almost completely supplanted steam as heat carrier, transferring to the environment. .... |
calculate heat load of a building, it is important to use an organized, step-by-step procedure. The necessary actions can be outlined as follows:
- Select design values for active winter design (97.5 percent of the value) of the Table. 4-3.
- Select indoor design temperature corresponding activities to be carried out in space and minimum permissible relative humidity.
- Determine whether any special conditions will be e^ist, for example, adjacent to the unconditioned spaces. Estimate of the temperature in the absolute space as needed.
- On the basis of plans and specifications, calculate the heat-transfer coefficients and the plots for the construction of components in each building envelope. Any surface connection with spaces be maintained at the same temperature can drop, i.e., internal walls.
- On the basis of building components, systems design and operation, wind speed, and an indoor-outdoor temperature difference, estimate the rate of infiltration and/or ventilation with outside air. Please note that the latent component of penetration and/or ventilation load is only connected if the air conditioning moisture to maintain a certain minimum level of humidity.
Hydration is often omitted from air conditioning systems in mild climates.
- Using the above data, calculate the transmission heat loss for each surface of the fencing construction and heat losses for infiltration and/or ventilation. The sum of these values to determine the total estimated loss of heat, as well as the necessary capacity of heating equipment.
- Consider any special circumstances that may influence the choice of equipment. Three circumstances may affect the operation of the equipment.
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design conditions is usually indicated to assess the thermal load inside and outside dry bulb thermometer temperature. For heating operation room temperature 20-22C is generally assumed and cooling mode, 24-26C is typical. Minimum relative humidity of 30% in winter and up to 60% in summer is expected. In cooling or heating mode 915% of the value of the external temperature is usually chosen. This means that on a long term basis outside of the dry bulb thermometer temperature equals or exceeds this value for 915% of the time during the coldest months of the year. In 975% temperature of the outside air is considered to be saturated. .... |
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Heat transfer through the building envelope depends on the materials used; geometric factors, such as size, shape, and orientation; - availability of internal sources of heat; and climatic factors. System design requires each of these factors for the study and the impact of their interactions to be carefully assessed.
The main function of heat loss and heat calculation of profit : assessment of capacity that will be needed for different heating and air-conditioning components necessary to maintain comfort in space. These calculations are therefore based on the maximum load for heating and cooling and corresponds to the climatic conditions, which are far from the extremes that are usual. Standard exterior design values of temperature, humidity and sunlight, can usually be obtained from the directory..... |
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Air quality must be maintained to ensure a healthy, comfortable environment indoors. Sources of pollution exist in both the internal and external environment. Indoor air quality is controlled for the removal of pollutants or by dilution. Ventilation plays an important role in both processes. Ventilation is defined as air, natural or mechanical means to the place. As a rule, the ventilation air from the outside air and recirculated air. Outdoor air dilution. In most cases, odor and irritation of the upper respiratory tract and eyes reason for ventilation, but not the presence of hazardous substances. The possibility of polluting substances should not be overlooked, however. .... |
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