Economic Analysis of Air - source Heat Pump Hot Water System School Bathing Projects

Home central air conditioning compared with the traditional home air conditioners, the indoor air distribution is more reasonable, uniform temperature, the temperature fluctuations in the room is small; the use of indoor ceiling mounted indoor unit, air supply pipes, refrigerant pipes or pipes conveniently placed Ceiling, and melt into the whole effect of installation; home central air conditioning generally use a host per household, to avoid the use of more than one split air conditioner caused by excessive outdoor unit appearance and the entire building caused by unsafe Hidden risks (outdoor unit installed outside the building may fall due to long-term wind and rain of the mounting rack), beautify the residential environment; greatly improve the traditional indoor air conditioner indoor unit connection pipe exposed and suspended in the indoor air Indecent issues.

2 home central air conditioning installation problems and solutions

Due to the particularity of household central air conditioning, its use effect and installation design and installation quality have a great relationship, not the general installation company can be installed, but should be a professional home air-conditioning installation company. Before installation, the installation personnel should carefully check the details of the installation of household central air conditioning, installation and coordination of design and coordination should be carried out. However, the current home central air conditioning installation market is quite confusing. In the process of design and installation, the installer does not provide detailed installation instructions and does not calculate and consider the actual energy efficiency of air conditioners. The technical quality of installers is poor, and some construction teams often find no To have a professional certificate of installation technicians, the installation of serious quality problems; the installation process does not provide users with options, can not be based on the performance of brand-name machines installed on the air conditioner in the course of problems can not be completely Bear the responsibility of the contract does not publicize the installation of the required list of materials, material costs are not publicity details, in the construction process shoddy, deceive users.

If the above situation is not completely changed, it is bound to have a greater negative impact on the promotion and use of home-based central air conditioners that have just started. Therefore, manufacturers should take effective measures to strengthen the training of installers, in particular, the introduction of new products and new technologies, but also to make great efforts to do this work, otherwise, not only cause greater economic losses to users , But also smashed the manufacturer's air conditioning brand.

According to the current home central air-conditioning installation process, the author put forward some problems that should be noted for the reference of the relevant personnel.

(1) outdoor unit installation

Home central air-conditioning outdoor unit, for independent residential buildings, can be installed outdoors based on the set, you can also be placed on the roof, the noise on the neighbors and indoor less. As for the collective building, it can only be set on the open balcony or on the stage (except the top floor). Some installers did not take any anti-vibration measures, the outdoor air conditioner directly placed outdoor open space (balcony or pick the basis of the platform), or through a simple shelf hanging on the wall, the machine is running (especially at night) indoor And the neighbors a great impact, the noise generated not only affect the user, but also affect the neighbors peace, resulting in neighborhood conflicts, and even complaints have occurred.

During installation, the outdoor unit should be located as close as possible to the indoor unit to shorten the cooling process pipe and be as low as possible in the indoor unit. The height difference is generally within 5000 mm; if possible, install it wherever possible or install it without noise Of the fastening table, the base should be set under the rubber shock absorber or strip thickness within 10 mm of rubber to keep the outdoor unit stable operation; in order to make the outdoor unit heat exchanger has a good heat transfer conditions, into Ventilation should be smooth, to avoid the phenomenon of backflow, the outdoor unit should be left side of the wall more than 200 mm gap; off-site installation in the street, you must make the bottom of the unit

2500 mm above the ground, can not hinder the traffic and pedestrians walking; outdoor machine discharge of hot (cold) wind, not close to neighbors or passersby, if necessary, should set the guide fence panels; in the air pollution and acid rain is more serious and air Coastal areas with more salt, in order to prevent the outdoor unit rust and reduce the service life of air conditioners, but also to avoid direct sunlight, improve the cooling effect of the unit, without prejudice to the case of air circulation should be set awning; When the upper part of the modular building is installed, the drainage of the outdoor unit (defrosting water when the heat pump is in use), including the condensation of the indoor unit, should be connected to the centralized sewer pipe of the building so as not to affect the normal life and the pedestrian's walking downstairs.

(2) installation of indoor unit

Indoor unit is an important part of duct-type household central air conditioning, due to the installation of the cause of indoor unit leaking, the noise is too often occur from time to time, and even seriously affect the normal use of air conditioning unit.

The construction of indoor units, first of all in accordance with the design drawings specified location of the installation, there is no special reason not to change the installation location. Indoor unit can not be installed in the room where people often stay (rest), the best set in the storage room, the walkway above; installation of the crane, care and support must be solid, the indoor unit must be installed level, without skew to ensure that Condensate water tray no water, no leakage; between the mounting bracket and the unit should have good vibration damping rubber or rubber skin; the outlet from the indoor unit of the condensate pipes do not use cheap plastic hose, but should U-PVC pipe, the horizontal section of about 5% of the slope, fixed solid, can not have bending phenomenon, the vertical pipe should be vertical, all of the condensate outlet pipe before the fixed have good insulation measures to prevent summer Dew drop when using the phenomenon. Condensate discharge should be installed according to the design requirements of the water seal elbow, and according to the relevant specifications or unit instructions set requirements. Drainage test must be done after the installation to ensure that the drainage is clear; below the unit should be 25 mm thick damping sound-absorbing panels, sound-absorbing panels should be greater than the area of ​​the base unit. Install the upper part of the indoor unit space and around the porous material to be acoustically-acted (eg sponge). When the natural attenuation can not meet the allowable noise standards, the muffler should be set. In order to prevent the transmission of vibration, the connection between the unit and the supply plenum should be soft and not hard. According to the domestic environmental standards, the allowable noise in the house is less than or equal to 50 dB (A) in daytime and ≤40 dB (A) in night. In order to facilitate overhaul, there should be a maintenance activity door at the operating end of the indoor unit during ceiling loading. Users are often overlooked, leading to trouble in the future maintenance.

(3) fan coil installation

Fan coil is the end of the duct system. No qualified installation company in the installation of the project often have such problems: noisy, poor results, fan coil below the drip. What is more, some installers to the fan coil closed in the ceiling mounted play, only the outlet without a return air inlet, simply can not be used normally.

In the installation of fan coil, the first to install a solid, horizontal; fan coil and the upper and lower pipes should be connected to the metal hose connection, the pipeline can not be formed at the balloon, otherwise it will result in poor water flow caused Air conditioning effect decreased; condensate water pipe handling system with the indoor unit; outlet should be installed in the indoor activities of the main places, intake and exhaust should be free from obstructions, the two should be a certain distance, can not form a short circuit. Tuyere surface should be horizontal and vertical, must be close to the wall or decorative panels, to make it beautiful and generous.

(4) the installation of water pipes

Water system, the upper and lower water pipe installation is relatively simple, the main problem is the individual installation of the project, the water pipe ignored the insulation measures, resulting in dew condensation phenomenon after use, which should cause the installation company attaches great importance. Generally do a good job in pipe rust-proof treatment, outside the pipe to do insulation treatment; In addition, the water pipe installation is completed, the pressure test must be carried out, the test pressure of not less than 1.5 times the working pressure; water pipe should be firmly fixed, two fixed points The distance between them is not more than 2000mm. When the water pipe encounters an obstacle (such as a ring beam), the airbag should be avoided (that is, the water pipe should pass under the obstacle and can not pass above the obstacle) ; The water pipe must be drained tightly before communicating with the air conditioning unit (the water color and transparency of the discharge port are similar to the population and there is no visible debris); The expansion tank of the water system (from the replenishment of water, constant pressure expansion and removal of non-condensable gases Effect) is generally installed at the highest point of the system, for home use small water system should be higher than the user's maximum water point at least 500 mm, expansion tank expansion pipe should be connected to the pump population, expansion tank generally installed by the company Construction and installation of construction.

(5) refrigerant pipe installation

Air conditioning unit of the process pipe (refrigerant pipe) size according to the design requirements, Ning big suddenly small, rather short suddenly long, the entire connecting pipe should not be flat, insulation outside the pipe should be intact pipe joints need to be welded Expansion or casing with the way. After welding is completed, it must be strictly leak-checked, and high-pressure nitrogen should be used to clean out the scale and other dirt in the pipe. For the VRV-type household central air conditioner, the sealing of the process pipe is more strict. Due to the large charge of refrigerant in the VRV system, a large amount of freon refrigerant leaked from the system may cause the air in the room to be evacuated once a leak occurs in a pipe or heat exchanger of a room of the user Indoor personnel in the process of sleeping serious choking occurred, so pay special attention to the sealing of the VRV system.

(6) duct installation

First of all, the production of duct to meet the design requirements of manufacturers. Some installation companies in order to save costs, the use of poor quality metal or other harmful materials used to make duct, has seriously affected the life of the unit, and may cause unnecessary harm to the user during use. In particular, it should be pointed out that if the duct made of composite material is covered with a non-combustible material, the internal insulating material should also be non-combustible or flame retardant and harmless to the human body. The thickness of the heat insulation material used for the air duct shall meet the requirement of dew condensation without dew phenomenon. The paste should be firm, the laying should be smooth, the lashing should be close, no slip, relaxation and breakage phenomenon.

Supply air duct installation, must meet the design requirements of manufacturers. Installation should be solid, all cranes, cradles and cradles shall not impede the operation of tuyere, valve, control system and inspection door, and make good anti-rust treatment; duct must be straight, without strong twisting, crushing, dead bending, etc. Phenomenon, the level of the gradient of the duct is not more than 3%; Duct and duct docking at the junction before the first coated with adhesive and then docking, seams should be pasted with the connection bar and the corresponding insulation treatment; in order to reduce Noise, the beginning of the duct (and blower connection) should not be sharp, if necessary, elbow and tee branch should be installed with guide vanes. The ratio of the long and short sides of the rectangular duct should not be larger than 4: 1. The cross-sectional area should control the flow rate in the duct by 3 m / s. The duct runs through the wall and the gap around the hole should be filled with elastic material.

In addition to the installation of new air duct should comply with the provisions of the supply pipe installation, but also should be designed according to slope design (slope to the new outlet), the new outlet to have rain and filter cover, the installation location should be selected in the air pollution The place and easy maintenance.

(7) Electrical equipment installation

In the electrical equipment installation process, the problems that often appear mainly in the following two situations: First, the unit's power wiring is not a dedicated line, cable, wire installation does not meet the requirements; Second, the installation company in order to save costs, the electrical equipment used In line with national electrical standards.

For safety reasons, the cable, electric wire and electrical accessories selected for household central air conditioning installation must use the national compulsory certification products; the unit should be set up a dedicated power supply, matched to meet the power of air conditioning equipment, and separate installation of the corresponding capacity leakage protector, Air switch and other protective devices; concealed works of cables, control lines and refrigerant pipe bundled together with the wiring, but should be arranged separately through the tube; the control panel is generally installed in the living room, living room and so easy to operate, does not affect the aesthetics of the room Room temperature probe generally according to the user's requirements to install a reasonable position.

3 Conclusion

In order to meet the needs of the development of the industry, standardize the market, all air-conditioning manufacturers to strengthen the quality control of home central air-conditioning installation project, unified home central air-conditioning installation project construction standards to protect users, manufacturers and installation of the interests of construction units. Domestic central air conditioning is still in our country at the guidance period, is in a steady upward trend, the market has great potential, but it must not because of the problems of the installation sector and the normal development of the entire industry.