Weak current College】 【roof air conditioner unit characteristics, use and settings.

Roof air conditioner (RooftopHVACUnits hereinafter RTU) is a unit of the integral units, refrigeration, heating, ventilation, air purification, electric control, assembled in one, installed on the roof, so that the roof air conditioner. In recent years, the RTU to its compact structure, a wide range of energy, convenient to regulate and to reduce installation time and cost advantages are increasingly applied to air conditioning.

1 unit features

1.1 unit structure is compact, with heat and cold sources, air cooling. In recent years, the unit number to a modular design, convenient combination, eliminating water cooling system.

1.2 unit in structural measures taking into account the rain, installed in the roof or on the outdoor terrace, you can open the rain and Sun.

1.3 unit comes with full computer control, a high degree of automation and unit electrical connection is compact, simply connect a small amount of control and the main power cable.

1.4 unit refrigeration system efficient and reliable, can meet the requirements of the various types of air-conditioning, condenser and evaporator is usually copper with aluminum finned tube, high heat transfer efficiency.

1.5RTU does not occupy the effective area of the room. In some areas, you can save electricity than water-cooled units.

2 roof air conditioner in the applicable area

2.1 water cooler to wet-bulb temperature, and air cooling machines to dry-bulb temperature, so the RTU General in one day dry-bulb temperature changes in the larger region use more favourable, as China's Shenzhen and Hong Kong.

2.2RTU since air cooling, so can be used to water deficit zone, like a Middle Eastern countries and the United States by the most used RTU. LasVegas China Hong Kong area due to lack of water resources, the Government requires the best air-conditioning design without cooling tower, so many buildings using RTU.

2.3 water cooler from building height restrictions, water pressure can not be too high, usually a line height 100m, cooling tower of the setting affects architectural appearance, so the current international 200m above too many ultra high building with air cooling machines.

Set of 3 units

3.1 roof unit setting, first select the most economical installation location, which is selected in the load set to reduce network cost.

3.2 to consider the impact of noise on the environment. Unit noise should not exceed the permitted noise standard, information display within the distance unit 5m, noise standard, from the machine noise from 5m less impact on the environment, but in a greater impact than 5m, so the best in residential buildings 5m above settings set. Present noise reduction measures in addition to the surface where you want to group or acoustical materials with installation, you can also set the compressor in the enclosures. In addition, reducing the exhaust fan rotational speeds, into the outlet located silencing devices are effective measures to reduce noise.

3.3 to consider for the effect of vibration on the buildings to prevent solid sound into the working and living environment. Usually in the unit you want to set rubber, in the inlet and outlet connectors located on the vibration reduction, and as far as possible be set layout in a load-bearing walls that prevent settings in roof panel mid-time hygiene resonance.

3.4 unit setting you want to consider building on the location of the exhaust fan and air vents, because those parts of the exhaust air flow will affect the flow of air on the roof, the RTU with vents at arm's length.

3.5 local wind conditions affect the operation of the unit's cooling fan. When the fan with the free rotation, will make the condenser of the air flow is blocked, and the unidirectional rotation of the fan housing to prevent the above phenomenon. In addition, the wind makes lighter RTU is difficult to maintain stability, so local wind conditions should also be considered.

3.6 for tall buildings must consider whether the crane's power is limited, so be sure before installation unit weight.

4 Select and considerations when installing the unit

4.1 unit of air tightness and Panel of leakage is important, rain, snow, dust, cold and hot air travel with air infiltration capacity of the unit, reducing the service life. In addition to considering the roof slope, so that the unit level.

A large number of condensing unit 4.2 promptly excluded, as there is water, the propagation of microbiological and algal growth and affect air quality. The condensate water should not be discharged in the roof, gray this will reduce roof surface layer of life, generally available through sewer discharge.

4.3 trap best installed on the machine itself, to prevent freezing.

4.4 roof unit of condenser coil fin, due to exposure to the outside air, the serious phenomenon of dust, reducing the efficiency of the condenser. At present, foreign companies design out of the unit comes with a small water pump of regular washing system, but because the system is technically complex, domestic machine still in active exploration and transformation phase.

5 conclusions

With the development of urban construction, building requirements, no roof unit of air-cooled cooling tower will be more and more, as energy-saving work of propulsion, roof air conditioner will increasingly be users especially water deficit zone users.