The new fan unit mainly deals with the state of outdoor fresh air, and the air filter unit deals with the state of indoor circulating air. Compared with fan coil unit plus fresh air system and unit air conditioner, it has the advantages of large air volume, high air quality, energy saving, etc., and is especially suitable for large space and adult system systems such as shopping malls, exhibition halls, and airports. A good air handling unit should have the characteristics of occupying less space, more functions, low noise, low energy consumption, beautiful appearance, and convenient installation and maintenance. However, due to its many functional sections and complicated structure, to take care of this without losing one’s attention, it is necessary to compare the design staff and the construction unit in materials, manufacturing processes, structural characteristics, and selection calculations before they can obtain More satisfactory results.
Air handling unit (Air handling unit, AHU) is mainly used to adjust the temperature, humidity and cleanliness of indoor air. There are air heaters, air coolers, air humidifiers to meet the needs of heat and humidity treatment, air filters to purify the air, mixing boxes for adjusting the fresh air and return air, and mufflers to reduce the noise of the ventilator. The air handling units are equipped with fans. According to the needs of air conditioning throughout the year, the unit can be equipped with an automatic conditioning system connected to cold and heat sources. It can be made into a series of fixed products by the factory. The air filter constitutes a processing section with various capacities and functions, which can be selected by the designer and assembled on site. Generally, the capacity is large (the air volume is more than 5000 cubic meters / hour), so it does not have an independent cold and heat source.
The air used in the comfortable air-conditioning environment has certain requirements on how to select the junior high-efficiency air filter for the processing unit. Generally, the indoor dust concentration is 0.15 ～ 0.25mg / m3, and the dust particles ≥10μm should be filtered out. The air filter section of this type of air handling unit only needs to be equipped with coarse and medium efficiency filters. For the above-mentioned special industries, high-efficiency filters need to be configured to achieve ultra-clean purification, which requires very high purification. The dust concentration of indoor air is expressed by the particle count concentration (particles / L).
How to choose junior high efficiency air filter for air handling unit? Generally, the air filter is selected as:
Effective filter G3; Intermediate efficiency bag filter F5, F6; Intermediate high efficiency air filter F7, F8; Sub-efficient air filter F9, H10 How to use junior high efficiency air filter?
Structural features: <1> OF adopts an external slide-type installation, which does not occupy a single segment length. <2> The built-in PF primary effect filter is installed with a slide-type installation, and the segment length is 1M. <3> BF and HF adopt frame box installation; fastening methods are divided into clips and bolts.
Filters are divided into: primary effect filters (usually referred to as G grade), intermediate effect filters (usually referred to as F grade), and high efficiency filters
The primary effect filter is divided into: G1 \ G2 \ G3 \ G4 (G4 is the primary filter effect * high, others are arranged in order)
The medium-efficiency filters are divided into: F5 \ F6 \ F7 \ F8 \ (F8 is the medium-effect filter’s filtering effect * high, others are arranged in order)
High-efficiency filters are divided into: 300,000-level filters \ 100,000-level filters \ 100-level filters (100-level filters are highly effective filtering effects
High, others in order)
The mainstream filters in the market are: non-woven filter \ belt filter \ metal filter \ paper filter \ nylon mesh filter \ glass fiber filter \ 3M filter (a low-cost filter launched by 3M company in recent years (Resistance, high efficiency energy-saving air filter)
Dust in the air has an impact on human health and product quality, especially in some special industries, such as precision instruments, electronics, pharmaceutical industry, hospitals, etc., which require extremely high air cleanliness. This needs to be selected according to the needs of different industries.
As mentioned above, how to select junior high-efficiency air filters for air handling units is mostly used in systems with large air volume (usually above 10000m3 / h), so their external dimensions are often large. In modern buildings, due to the investment and functions of the developer or the owner, the size of the machine room is often compressed to a very small size, which can easily cause surface coolers, filters, and other components that require routine maintenance and cleaning due to the small space, unable to extract or difficult to extract. Some of the equipment maintenance lanes originally reserved after the construction was completed are inaccessible when the equipment needs to be replaced or repaired.
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