Twin-Unit Air Shower
Product Overview
Features & Specifications
Detailed Description
Two ways to "enlarge": deeper and wider
The twin-unit type comes in two forms. Deeper connects two shower sections one behind the other, for a depth of approx. 2000 mm, with two people standing one in front of the other, or one person with a trolley; the number of nozzles doubles with the depth, to about 24 on both sides. Wider makes the internal width of the enclosure larger than the approx. 800 mm of a typical single-person unit so that wide trolleys or material racks can pass through; the width is custom-made to the outer edge of the handling equipment. The first thing to confirm is "who the extra space is for": for people, go deeper; for wide materials, go wider; if both are needed, the enclosure becomes both deeper and wider, and the fans and nozzle arrangement increase accordingly.| Approach | Typical dimensions | Nozzles | Suited to |
|---|---|---|---|
| Deeper (two-person) | External approx. 1400–1500 × 2000 mm | About 24 on both sides | Two people at once, or one person with a trolley |
| Deeper (three or more people) | Depth approx. 2400–3000 mm | About 36 on both sides | A small team entering together |
| Wider | Internal width custom-made to the outer edge of the trolley or material rack | According to the enclosure layout | Wide trolleys, material racks |
With several people showering at once, the nozzles must increase too
When two people stand in the same enclosure, each blocks the airflow on one side of the other; if the number of nozzles is not increased accordingly, the area actually reached on each person is reduced. According to available sources, China's JG/T 296-2010 (Air Shower) requires the number of nozzles in a two-person unit to be 2 times the single-person table value; the typical two-person configuration of about 24 nozzles and single-person configuration of about 12 reflect exactly this ratio. Even with the nozzles doubled, the two people should stand in the front and rear sections respectively and each turn around during the shower, rather than standing side by side in the same section.Showering trolleys and materials together
The wheels and handles of a trolley and the outer packaging of the tote boxes on it are all surfaces that accumulate settled dust in non-clean areas. Entering the twin-unit air shower together with a person removes the loose particles on these surfaces, which is better than no treatment at all. But its limits must be clear: EU GMP Annex 1 (2022) §4.10 and §4.11 list material transfer as one of the main sources of contamination in clean areas, and materials entering Grade A / B must go through a validated disinfection procedure. A shower cannot deal with microorganisms adhering to packaging, nor with areas below horizontal surfaces that are hidden by tote boxes. Outer cardboard boxes should be removed before entry, and trolleys and tote boxes wiped according to procedure.Should people and trolleys share an entrance
When trolleys enter only occasionally, the twin-unit type lets a person and a trolley share one cycle, saving time and space. If large volumes of material go in and out every day, people will queue at the entrance waiting for materials to be showered; and with people and materials in the same enclosed space, the particles blown off will deposit on each other. In that case materials should be diverted to a pass box or a cargo air shower tunnel, leaving the twin-unit type to handle only people and small personal trolleys. To decide, record the number and timing of trolley entries each day over a period; if they are concentrated during the peak entry times of personnel, the benefit of separating the flows is most obvious.Door openings and floors
For trolleys to go in and out, the door opening must be wider than the trolley's outer edge with clearance on both sides, and the threshold must be flush with the floor; otherwise each time a trolley crosses the threshold, particles are shaken off the trolley and the door frame is easily damaged. The floor material must withstand long-term rolling of trolley wheels, and its cleaning method should be considered together with the enclosure.Frequently Asked Questions
What is the difference between a twin-unit air shower and a multi-person air shower tunnel?
The twin-unit type is a deeper (approx. 2000 mm) or wider enclosure in which two people, or a person with a trolley, are showered standing in place in one cycle, typically with about 24 nozzles and 2.2 kW for two people; a multi-person tunnel is a corridor of 1500 mm modules connected in series, in which people are showered as they walk, suited to shifts of dozens to hundreds of people entering at once. Choose the twin-unit type for entrances with few people but frequent trolleys; choose a tunnel for entrances with heavy peak foot traffic.
If two people go in at once, is the shower less effective?
It will be if the number of nozzles is not increased, because the two people block the airflow on one side of each other. According to available sources, JG/T 296-2010 requires the number of nozzles in a two-person unit to be 2 times the single-person table value; a typical two-person configuration has about 24 nozzles, and a single-person one about 12. In use, the two people should stand in the front and rear sections respectively and each turn around during the shower, rather than squeezing side by side into the same section.
Can trolleys be showered together with people?
Yes, the shower can remove loose settled dust from trolley wheels, handles and the outer surfaces of tote boxes. But the shower does not sterilize, nor can it reach hidden surfaces; under EU GMP Annex 1 (2022) §4.10 and §4.11, materials entering Grade A / B must go through a validated disinfection procedure. Outer cardboard boxes should be removed before entry and trolleys wiped according to procedure; if large volumes of material go in and out every day, a separate pass box or cargo air shower tunnel should be set up to divert them.
Selection References
Before ordering, verify the efficiency grade, media type, and whether the operating environment fits your requirements.
