Germicidal access doors

RAMI-SYSTEM® germicidal access doors are a new patented system that adds a new function to our access doors: the sterilization of air in ducts of air-conditioned recirculation installations.

This air purification system is especially recommended for surgery rooms, clean rooms, hospitals, clinics, laboratories, food industry, pharmacy, etc … and, additionally, for schools, waiting rooms in general, offices, restaurants, discos, theaters, cinemas, casinos, libraries, gyms, shops, etc …

With these doors, bacteria, yeasts, mold spores, viruses, protozoa, algae, etc … are exterminated by UV-C radiation, between wavelengths of 100 to 280 nm (nanometers), generated by powerful  low pressure mercury vapor PHILIPS lamps from the TUV PL-L HO range, emitting short wave ultraviolet light with a precise wavelength of 254 nm. Therefore, this type of lamp does NOT generate ozone (<240 nm).

If you want to know more, you can access: https://www.assets.signify.com/is/content/PhilipsLighting/Assets/philips-lighting/global/20200504-philips-uv-purification-application-information.pdf

For each type of germ there is a certain dose to neutralize its DNA, preventing its reproduction and, consequently, causing its elimination. For example, the dose to neutralize the SARS-Cov-2 (COVID-19) coronavirus by 90% is 29 mJ / cm².

Faced with possible improper openings, RAMI-SYSTEM® germicidal access doors have an automatic electrical disconnection system that prevents radiation to the outside, since it is totally contraindicated for people or animals and direct exposure must always be avoided. For our tapas, the dose allowed to people per day and 1 meter away, ranges between 30 sec. for those of 70 W and 10 sec. for those of 190W. Therefore, we insist on not exposing yourself to that radiation at all. To consult the limit exposure scaling, download this PDF: https://rami-system.es/wp-content/uploads/2021/01/ALLOWED-RADIATIONS.pdf

It consists of 3 trays of the same size assembled using 100 mm long screws. The lamps with their bases, supports, control photocells and connection components are mounted on the inside of the duct. The 2 inner trays work between them in a conventional way, making the duct watertight. In the cavity formed between the intermediate tray and the outer one, there are the peripheral elements: drivers, safety and control components, closed perimeter with a 40 mm weatherstrip.

Two lamps are always mounted per door with patented mechanical safety fixing that prevents vibrations of the lamps due to high air speeds that could even disconnect them. With external LEDs to indicate operation and brightness level. These lamps have a 9,000 h life and their periodic maintenance for cleaning the lamps, or their replacement, is carried out without having to use tools.

As recommendations to achieve the optimal performance of the lamps, it is necessary to ensure the quality of cleaning of the air that is blown into the ducts and, for this, it is recommended that the filters are kept in perfect condition, since the dust that could be deposited on lamps, it would significantly reduce disinfection management.

A high level of humidity in the treated air also reduces the performance of the lamps.

On the contrary, a factor that increases performance throughout the radiation range is – apart from cleaning – painting the interior walls of the duct with reflective paint of the glossy aluminum type with a mirror effect finish.

These types of doors are manufactured to be applied in rectangular, circular or oval section ducts and the assembly is carried out with the same specifications as our standard access doors.

In installations with RAMI-SYSTEM® access doors, these can be instantly replaced by germicidal access doors without the use of tools.

We have also developed a computer tool that allows us to instantly calculate the number of doors, size, power consumed, etc … that will be necessary to neutralize any type of parasite in the desired time from these data provided by the client:

• Type of germ to be sterilized
• Duct dimension
• Airspeed
• Interior area to be treated with its average height
• Minimum blown air temperature

Inside view of a 300 x 200 flat germicidal access door, placed in a 400 x 400 mm duct with 2 UV-C lamps of 35 W each

Detail of the external LED indicators of operation and intensity of radiation of each of the 2 lamps

Below we will present a supposed practical case in which, apart from being able to analyze the different combinations that can be made by varying the number of access doors and the disinfection time, we will see the great impact that the temperature of the recirculated air has on the results obtained for a certain disinfection.

Our computer application, for the calculation of access doors, always prioritizes the highest power of the mounted lamps over the largest size of access doors that can be installed according to the size of the proposed duct.

Let’s assume an installation with:

A rectangular duct section of 500 × 300 mm with air speed of 2 m / s. An area of ​​80 m² with 2.7 m of average height that corresponds to a volume of 216 m³ and a temperature of the driven air in summer of 10ºC, gives us a result of:

• 4 access doors of 300 × 200 of 120W
• A total consumed power of 480 W
• A disinfection time of 72 min
• With 6 volume recirculation

O well:

• 3 access doors of 300 × 200 of 120W
• A total consumed power of 360 W
• A disinfection time of 96 min
• With 8 volume recirculation

Then, for the same installation but with a driven air temperature in winter of 50º C, we would have:

• 3 access doors of 300 × 200 of 120W
• A total consumed power of 360 W
• A disinfection time of 24 min
• With 2 volume recirculation

O well:

• 2 access doors of 300 × 200  of 120W
• A total power consumption of 240 W
• A disinfection time of 36 min
• With 3 volume recirculation

Obtaining information from the advanced technology of PHILIPS, we see that these lamps have their maximum efficiency at 40º C and their performance in UV-C radiation decreases considerably with lower temperatures. For this reason it is vital to consider the temperature at which they are going to work.

With the calculation tool that we have specifically developed, we can instantly provide you with the results that best suit your installation, including the economic evaluation that best suits your needs based on the time set to perform the sterilization.

Below we detail the relationship of pathogenic germs (with their corresponding dose values) that would also be exterminated by 90% with the mentioned dose of 29mJ / cm², since they generally correspond to a lower dose:

BACTERIA:

MOLD SPORES:

VIRUS:

YEASTS:

PROTOZOA:

ALGAE: