How it works
The Pure Air Generator contains the filters a high speed blower, two 3,350 mAh 18650 lithium ion batteries, the Ultra High Intensity UVC LED, the Reflective Irradiation Chamber and Electronics that are required to manage blower speed, LED Voltage and battery charging.
The blower has three speeds classified as “Normal” “High” and “Very High”. The battery life for these three speeds is 10 hours, 8 hours and 6 hours. The higher speeds are only necessary if you are occupied in strenuous activity, or if your glasses continue to fog up after entering a very low temperature space.
The Pure Air Generator has two filter screens on either side attached with magnets to the Generator body. These screens hold the replaceable filters which are simple ro remove and replace using this patented magnet attachment method.
The Air Delivery Tube connects to the Pure Air Generator and transfers the purified air to the Air Curtain. This tube can be cut to length to suit how and where the Pure Air generator is located. Tubes can become damaged with use and spare tubes are available on request. A spare tube comes with a standard order.
The Air Curtain is an ergonomically designed hollow plastic structure that transfers the purified air from the back of the neck to the chin directing a stream of pure air up under the lips and towards the nostrils. It weighs twelve grams. It has small dimples on its back face that hold the plastic off the skin preventing any skin irritation. Small holes in the cavity created by these dimples allow some of the air to “breathe” under the chin further minimizing any possible discomfort or skin irritation.
The Air Curtain is held in place using the mask and prevents the mask from rubbing against the chin lowering any risk of skin irritation. It can also be held directly using elastic straps around the ears. This may be necessary with some mask designs that do not pass under the chin and provide adequate support.
The Magnetic Attachment Strip is a plastic strip containing two powerful magnets that align with the magnets used to hold the Filter Screens. It is used to attach the Pure Air Generator to your clothes. The Pure Air Generator can be worn on the outside of the clothes with the strip behind or on the inside with only the strip visible on the outside. It is not advisable to wear the Generator on the inside without an under garment or without a protective bag.
These magnets could interfere with a pacemaker and in this case the Pure Air Generator comes without magnets with the filter screens held inside a small pouch bag which is supported around the neck.
The technical details
Any small particles can remain suspended in the air for long periods and are inhaled as we breathe.
Particles can be classified on the basis of their size, referred to as their ‘aerodynamic diameter’. ‘Coarse particles’ are those between 10 and 2.5 microns in diameter; ‘fine particles’ are smaller than 2.5 µm; and ‘ultrafine particles’ are smaller than 0.1 µm. For comparison, the diameter of a human hair is 70 µm and this is seven times the diameter of the largest ‘coarse particles’.
Particles smaller than 1 micron can remain suspended in the air for days. The particles that leave our mouth when we talk range in size from 0.1 microns to 10 microns so although many of them will drop to the floor in minutes many remain around for a long time particularly as they dry out and reduce in size.
Most virusses particularly respiratory virusses are predominantly spread by inhalation of small airborne particles that are then drawn deep into the avoli cavities in the lungs. Even a single virus can cause infection, as if the virus enters a cell it reproduces thousands of itself within hours. The more virus you inhale the more likely that one of these particles will start the infection.
The particles larger than 10 microns generally do not make so deeply into the lungs and are often caught in the nasal and bronchial passages. It is the small particles that are the most dangerous.
Pollutants are similar with some of them damaging sensitive lung tissue and causing other health problems. The more effectively we can reduce the entry of small particles into our lungs the healthier we will be.
Most fabric filters consist of woven or non woven fibres that capture small particles suspended in the air as it passes through them. They perform this capture in typically Four different ways.
- The particles generally larger than 10 microns are simply caught inn the sieve like structure of the fabric.
- Particles below 10 microns have sufficient mass to simply run into a fibre in the fabric and are attracted to it with a force called Van der Waals force and remain in place
- Once the particles are smaller than 1-2 microns they do not have sufficient mass and follow the airstream around the fibres. They are also attached using Van der Waals forces but only if they become close enough to the fibre. This makes these particles the most difficult to capture with 0.3 micron particles being the most difficult.
- Once the particles are smaller than 0.3 microns they have such little mass that they begin to be affected by individual molecules in the gas stream and begin to execute a vibratory path.
- The vibratory path increases the chance that they will come close enough or actually touch one of the fibres and become attached to it.
Generally the two driving features of effective particle capture is the total surface area of the fibres in fabric that the air passes through. Generally the finer the fibre the greater the area the better the capture. The other is the flow rate with generally the larger the filter area the slower the flow and the more effective the capture.
However there is a 5th method of particle capture and that is electrostatic filtration. As the air passes through the filter the particles and the fibres loose and give up electrons in the same way as a plastic comb electrostatically attracts hair. The drier the fabric and air the greater the affect. When a mask is being worn the exhaled breath keeps the fabric damp and almost no electrostatic attraction is possible. With the Airin Smart Shield the filters are in the Pure Air Generator and they remain dry so the electrostatic attraction is important and the real time filtration efficiency much higher than with a unventilated mask.
The Airin Smart Shield has been independently tested and certified by the FDA-approved and ISO 17025 accredited SGS Labs with an overall filtration efficiency of 99%.
The CE-FFP2 (EU Standards N95 equivalent) passive air filter has been tested according to the EN 149-2001+A1-2009 standards, receiving a 0.3-micron filtration efficiency of 99.97%.
The air is sucked (not blown) through the filters increasing the effectiveness of the filter seal against perimeter leakage. The magnet attachment ensures that the free edge of the filter is very well sealed against the internal filter screen so that no leakage can occur when filters are installed correctly.
The concentration of CO2 in fresh air that we breathe in when outside is around 400 ppm or 0.04%. When inside in a typical occupied office building factory or shop it may reach 1,000 ppm. It will also contain around 21% oxygen.
The air we breath out contains an average of 4% to 5.3% CO2 or over 100 times more than the atmospheric level. It will still contain around 16% oxygen which is only 76% of the original value and plenty of oxygen to maintain oxygen levels in the blood. However if you were in a room breathing air containing 4% CO2 (40,000ppm) you will have difficulty maintaing your oxygen and CO2 levels where they should be and will exhibit signs of stress such as dizziness and headaches. At 10% CO2 levels you could pass out and at 25% CO2 you would die. This link discusses these realities.
This is why most N5 masks have this warning on them “Misuse may result in sickness or death”
It is also one of the reasons that the CDC and WHO dissuade the general public from wearing these masks, recommending masks that could never cause these high levels of CO2 to be used. Doctors and Nurses who must wear them to be safe from infection are given instructions in how to avoid the health risks and are made well aware of what to look for when wearing them.
When wearing a loose cloth mask or a Surgical Mask the levels of CO2 could never reach these very high levels no matter what the conditions but it is well understood that even levels above 1,500ppm begin to cause loss of cognitive ability in many individuals and above 2,500ppm dizziness and headaches. Most work place health and safety rules place a limit of 5,000 ppm for continuous work. Some allow 15,000ppm for 15 minutes.
Loss of cognitive ability can be extremely dangerous when a worker is required to operate dangerous or complex machinery and will always reduce productivity and cause mistakes.
It goes without saying that this same affect will be found with students who require very high levels of concentration when learning new concepts.
Masks increase the levels of CO2 being inhaled by the wearer. The actual concentration depends on the type of fabric, the seal to the face, the volume of air (dead space) between the mask fabric and the face, the volume of the breaths of the wearer and the time it is worn. It is a very complex issue but there is little doubt that wearing a mask is uncomfortable at best, will reduce learning ability and productivity and at worst cause health problems for some. There is also no doubt that during epidemics like Covid or in times of high pollution masks should be worn regardless.
It is essential that the level of rebreathed CO2 is reduced as much as possible. The Airin Smart Shield can maintain it at levels below what it would be in still air, without the mask because it is actively moving the CO2 away from the face. When wearing a mask with the Airin Smart Shield no loss of cognitive ability, productivity or learning capacity let alone health issues like stress headaches are likely. With just the mask they are.
In many situations wearing a mask causes glasses to be fogged up by the hot humid breath moving up out of the mask around the nose where the sealing is most difficult to accomplish. This is particularly annoying and will cause loss of productivity for workers and loss of attention for students.
When wearing the Arin Smart Shield the supply of pure dry air from the Pure Air Generator dilutes the humidity in the hot breath lessening the affect when exhaling and then demists the glasses once exhaling is completed. No fogging of glasses is experienced while wearing the Airin Smart Shield unless the ambient temperature is below 5 degrees Centigrade.
A particular wave length of the UV light spectrum has always been known to damage living cells. The damage is associated with the chemical bonds in the DNA and RNA molecules often rendering then incapable of replication and often resulting I cancers such as skin cancer.
The most effective wavelength is between 230nm and 275nm.
A purpose built LED (Light Emitting Diode) has been developed to create ultra-high levels of this wavelength when energized. The LED is protected by thin window of quartz which allows almost 100% of the light to pass through it. The light enters a chamber that is coated in highly reflective material so that it is reflected thousands of times before the air travels through the chamber exposing any virus particles to lethal levels of radiation. The reflective material ensures that no radiation escapes the chamber.
The UV-C active protection has been tested against E. coli and Staphylococcus to have an average efficacy rate of 99.93%.
The UV is produced in a range of frequencies between 230nm and 280nm which are known to damage DNA and RNA molecules. The ultra-high intensity LED producing the rays uses an input power of 500 mW emitting 5mW of radiant flux at a radiant concentration of 25,000µW/cm2
We breathe around 6 to10 litres per minute when relaxed and not exercising. This is typically accomplished using 15-20 individual breaths per minute of 500cc per breath.
When exercising this rate can increase to 120 litres per minute using up to 60 breaths per minute of up to two litres per breath.
The Pure Air Generator is designed to supply air at a rate that is always significantly more than the maximum inhalation rate up to moderate levels of exercise. On the lowest speed setting with clean filters it supplies 60 litres per minute which is twice the relaxed breathing rate ensuring that a high positive pressure is maintained behind the mask.
At the highest speed setting it delivers 100 litres per minute which will match the maximum breathing rate at moderate exercise. It is not intended to match the maximum breathing rate of someone exercising at their maximum capacity and the breathing would then rely on the porosity of the mask and no longer be able to rely on the positive pressure being maintained.
The blower is a silent centrifugal fan driven by a brushless DC motor drawing 2W of electrical power when operating at 12 Volts. It has three speeds utilizing three different drive voltages of 9V 11V and 13V. It spins on frictionless magnetic bearings. At 9V it is drawing
At 9 volts operating with clean filters it blows 60 litres of air per minute into the air curtain. At 9 volts the motor is drawing 0.9W of power
This is around three times the maximum breathing rate of a person when seated and not moving. This ensures that a positive pressure is maintained at all times with air always leaving the space under the mask and never sucked in to it. It also ensures that the hot humid breath containing high levels of CO2 will be flushed out between breaths. The typical dead volume behind a mask is 150cc which contains around 5% CO2. Air is entering this space at the rate of 1,000cc per second with blower operating at its lowest speed. In two seconds it will dilute the CO2 level from 5% to 0.5% ensuring the average inhalation of CO2 in a 300cc inhalation is below 0.2% (2,000ppm) . Without the blower the average inhalation of CO2 would be above 2.5% (25,000ppm) and would cause dizziness and headaches for many people.
At 13 volts this increases to 100 litres per minute which is around the breathing rate of someone carrying out relatively heavy exercise. If breathing in excess of 100 litres per minute the extra air will be drawn in through the mask fabric and the positive pressure will be temporarily lost. The CO2 levels will remain very similar because with 1,000cc breaths the dead-space containing the CO2 has less effect on raising the average CO2 inhalation rate.
The battery consists of two lithium ion 18650 3.7V cells of 3,350mAh each. The two of them contain 22Wh of useable electrical energy.
When the blower is operating at 9 volts and the LED is drawing 1W the Pure Air Generator will run for 10 – 12 hours. At 11 volts it will run for 8 -10 hours and at 13 volts 6-8 hours.
The PCB receives the voltage from the two battery cells in parallel at 4.2V to 2.6 V . It uses DC to DC converters to supply the three drive voltages for the fan. 9V, 11V, and 13V . It also uses a DC to DC converter to provide a very precise voltage to the LED to maintain the correct Ultra High Intensity UV light at the best killing wave length of 254nm.
A Battery Management System (BMS) is used to protect the battery during charging from over charge and switch the system off once the battery is discharged to 2.7V .
A switch is provided that is used to activate the blower . The three speeds are selected by repeatedly switching this switch to select the three drive voltages. One press for 9V two press for 11V and three press for 13 V with the fourth press turning it off.
Charging is accomplished using a conventional 5 Volt charger which plugs into the bottom of the Pure Air Generator and a Computer USB or phone charger. When charging a green light flashes and when fully charged it remains steady.
The filters come in packs of 200 with one placed on each side of the Pure Air Generator.
After using for one full day (8 hours) it is advisable to replace it. If pollution levels are very high it may be necessary to do this even more often.
It is advisable to remove the dirty filters without touching them using a toothpick or tweezers. Wipe the surfaces of the Pure Air Generator down with a cloth dampened using a sanitizing agent then replace with new filters.
Place the new filter in the Filter screen carefully so that it is accurately centered then place it on the body of the Pure Air Generator allowing the magnets to pull it on to the body. Use tweezers to accurately position if necessary. Repeat the process for the reverse side.
The system comes with a 30 day money back guarantee if dissatisfied with performance on return of undamaged device.
The Pure Air Generator and air curtain is guaranteed against defects in workmanship and materials for 12 months.
The batteries are guaranteed to maintain 80% of their initial charge capacity for 12 months.
Filters are available in packs of 200, spare delivery tubes and additional air curtains are available on request.
Replacement batteries are available and can be replaced by an experienced battery technician.