Portable Air Conditioners

Portable Air Conditioners2024-02-13T13:18:09+00:00

Portable Air Conditioners

Portable Air Conditioners

On average, people spend up to 90% of their time indoors, and indoor air can be two and a half times as polluted as outdoor air.

Indoor Air Quality is of particular concern for those with asthma and allergies, but a healthier home is of broader benefit to all.

The asthma & allergy friendly® Certification Program seeks to assist people to identify products which will make a genuine difference to their indoor environment. It develops certification standards for relevant categories of products, and all certified products undergo testing to those standards. In this way, the consumer can make an informed choice about materials like air cleaners, insulation, flooring products, etc. that they bring into their home.

In the case of portable air conditioners, customers want to be confident that their product can control temperature without introducing mold or redistributing allergen into the air. High humidity can facilitate dust mite and mold growth, and it is therefore important that a portable air conditioner can regulate humidity. Our standard addresses these issues.

Our portable air conditioner standard is one of over 50 standards in the asthma & allergy friendly® Certification Program, covering appliances, bedding products, air filters, building products, and services that can have an impact on the indoor air environment. You can explore the portable air conditioner standard in more detail using the menu on the left, or use the links above to explore other standards.



We’ll have a case study up here soon, but in the meantime please check out some of our other case studies




Standard Abstract ASP:10-03 Portable Air Conditioner

Portable air conditioners that are Certified asthma & allergy friendly® are tested to the ASP:10-03 Portable Air Conditioner Certification Standard. The Certification Standard utilizes an algorithm of proprietary and recognized scientific techniques to assess Air Conditioners for their ability to reduce allergenic and irritant materials. Submitted air conditioner models that pass certification testing are granted a certificate stating that the particular air conditioner meets the requirements for the asthma & allergy friendly® ASP:10-03 Certification Standard.

The Portable Air Conditioner Certification standard includes the evaluation of:

  1. The ability of the air conditioner to reduce and maintain temperature and humidity
  2. The effect of the air conditioner on pre-existing particles and allergens in a room where they are operated*
  3. The potential mold growth in the system or on the filter
  4. Ozone emissions
  5. Charged particles released from air conditioner units incorporating charged-particle-release technologies

*Some air conditioning units claim to have the capacity to reduce overall allergen burden. While this is not a requirement for asthma & allergy friendly® Certification, as air conditioning units are not primarily air cleaners, when these claims are made, such a beneficial impact must be demonstrable.

Part 1: Control over temperature and humidity

The term ‘thermal comfort’ is defined as being the ‘condition of mind which expresses satisfaction with the thermal environment’ and therefore relates to a number of factors that influence personal satisfaction with the surrounding. Temperature and relative humidity (RH) are two are factors relevant to people with asthma and allergy.

Criteria 1: A portable air conditioner unit must be capable of achieving a reduction of temperature from 35°C to 22°C +/- 10% and RH from 90% to 50% ±5% over 4 hours when used in a chamber of predetermined dimensions.

Criteria 2: A temperature of 22°C i.e. within the thermal comfort range, must be maintained within +/- 10% over a period of 8 hours. Relative humidity must be maintained +/-5% over the same time period.

Part 2: impact on airborne particles, including allergen

Portable air conditioning units have the potential to increase allergen and mold in indoor air. This increase, usually involving redistribution of indoor air, may negatively impact individuals with asthma and allergies. The impact may outweigh the benefits associated with optimization of thermal comfort. Certified air conditioner units must have a filtration capacity that, at a minimum, overcomes this potential negative outcome.

Criteria 3: Following operation for 120 minutes at maximum setting, there must be no increase in airborne levels of:

  1. allergens
  2. mold spores

Criteria 4: Any initial increase in allergen related particle counts (i.e. 1-25µm or greater), associated with running the air conditioner, must have returned to background levels in less than 60 minutes. Should such an increase occur within this time period, it must be less than 10% of the mean background level.

Criteria 5: Portable air conditioners that claim to reduce allergen exposure must show a mean reduction in allergen levels of 25% or greater over 120 minutes, when compared to mean background levels. Such reduction must be shown not to result from particle re-distribution.

Part 3: Potential mold growth in the system or on the filter

A reliance upon a media type filtration system does pose practical issues such as mold growth (carbon source provided by the filter) and high energy consumption.

Criteria 6: Filter change/wash recommendations are based upon modelled growth of fungi on the filters. These filter recommendations are then incorporated into the product care code.


Spore Count Increase*

Mycelial growth

Change/Wash recommendation




8 weeks




6 weeks




4 weeks




2 weeks




Not eligible for Certification

*Increase above inoculum level per 10 cm2

Part 4: Ozone

Criteria 7: The Code of Federal Regulations (CFR) section 21:801.415 requiring ozone exposure at less than 0.1 mg/m3 (50 ppb) must be achieved.

Part 5: Ion-generating technologies

Many modern, stand alone, air handling units incorporate technologies that generate charged particles. Some capture these within the product, others release the charged particles. Excluding ozone generation, no adverse health impact has been demonstrated where negative ion generation and release is concerned.

Criteria 8: Where portable air conditioners incorporate charged particle release technologies, at least 55% of the measurable airborne ions must be negatively charged.

Why and how we certify portable air conditioners – a Q&A

There is ever-increasing awareness of the chemicals and allergens we come into contact with every day, particularly if you or a member of your family has asthma or allergies. We created the asthma & allergy friendly® Certification Program to help you improve your indoor environment by identifying products and services that can help to reduce allergens and other triggers, and create a healthier home environment.

But what is it that makes some portable air conditioners better for the indoor environment than others, and where do we draw the line to decide to certify an air conditioner as asthma & allergy friendly® ? We hope that the questions below will clarify this. Let us know if you have more questions!

Why do you certify portable air conditioners?

Our goal in the asthma & allergy friendly® Certification Program is to create a healthier indoor environment for you and your family, as well as to reduce allergens in the home. So we look at all elements of the indoor air environment.

Effective air conditioners can modulate temperature in a room, and often the relative humidity (i.e. the moisture level in the air) also. Both of these elements can have an impact on asthma and allergies. Hot, humid air can be an asthma trigger. These conditions also allow dust mites to thrive and molds to grow. Air conditioners can also result in increased allergen levels in the air, because they create air flow which kicks up particles of pollen, pet dander and other allergens into the breathing zone.

When we test portable air conditioners, we look to recreate what happens in the home, so that we are testing the appliance in a way that is relevant to users. We make sure that it can do its job in terms of controlling temperature and relative humidity. But we also make sure that its use does not create additional allergen levels in the air. And we check to make sure that the water being removed from the air is not stored in a way that allows mold to grow.

Centralised air conditioning and HVAC systems can be costly to install, and this installation is sometimes not possible, for example in rented accommodation. Having a certification standard for portable air conditioners provides an option for trusted air conditioning where it is not feasible to have a central system.

How do you test portable air conditioners?

There are four parts to our portable air conditioner testing. These are designed to test the temperature and relative humidity controls of the product, the effect on allergen levels, how often the filters should be changed, and the release of ozone and charged particles from the air conditioner. You can find more details on each part of the testing below.

Impact on Allergen Level

We use a controlled environmental chamber to test air conditioners. We introduce test dust that contains allergen into the room through a vent. We run the air conditioner and monitor the particle level in the room. Once the test is finished, we suck all the air out of the room through a filter, so that any allergen that remains in the air is captured. We compare this to the amount of allergen in the air when there is no air conditioner in the room.

Our requirement is that there should be no increase in allergens and mold spores in the air over 120 minutes of the air conditioner operating in the chamber. If there is an initial increase in allergen levels (because the air conditioner is creating an air flow around the room), these must go back to normal in less than 60 minutes, and the increase must be under 10% of the normal level.

Some air conditioners have filters that can capture allergen and remove it from the air. In that case, we make sure that the air conditioner can remove at least 25% of the allergen from the chamber in 120 minutes.

Temperature and Relative Humidity

We set up the environmental chamber so that the temperature is 35°C and the relative humidity is 90%. Then we switch on the air conditioner and set it to 22°C and 50% relative humidity, and let it run for 12 hours. We make sure that the air conditioner can reduce the temperature and relative humidity and maintain this level over 12 hours.

Mold Growth on Filters

Air conditioners remove moisture from the air, and that moisture can create conditions within the air conditioner that allow for mold growth. One of the places this can happen is on the air conditioner’s filter. We take samples of the filter, and introduce mold to it. We then see if over two weeks there is a growth of mold. Based on the results, we make a recommendation on how often the filter needs to be changed to avoid this problem.


Some appliances can produce ozone as a side-effect of their operation. We make sure that if certified portable air conditioners do produce ozone particles, that they are at an extremely low level so it is unlikely to have an impact on the indoor environment. Portable air conditioners that are certified by us release less than 0.05 parts per million of ozone.

What about portable air conditioners that release charged particles?

Some air handling units can use technologies that generate and release charged particles (ions) into the environment – these have either a positive or negative charge, and when they transfer this charge to an allergen particle it causes the allergen particle to stick to a surface, removing it from the breathing zone. Because there is some research that supports the safety of negative ions, if a portable air conditioner has this technology, we require that the majority of ions produced by are negatively charged.

What else do you certify?

We have over 50 different asthma & allergy friendly® certification standards for products and services, addressing all areas of the indoor air environment. Some of these relate to products which remove allergens and dust from the indoor environment, like vacuum cleaners, air cleaners, dehumidifiers, and washing machines. Some of them relate to products where it is important not to provide an easy home for allergens and that it is possible to remove allergen from them – like bedding, toys, and flooring. And some of them relate to household products that should make as little an impact on the indoor environment as possible – like flooring and paint.

You can find out which products are certified asthma & allergy friendly® and read more here: www.asthmaandallergyfriendly.com

Portable Air Conditioners – A Good Choice For A Healthy Home?

This summer we are likely to spend more time in our homes than ever and with temperatures rising, it’s time to tackle any issues with our air conditioning. Living in a space that is too hot and sticky can be difficult. Tempers fray, sleep suffers, babies and small children get cranky. But it’s not just our mood that is impacted. Our health is effected too.

Air Conditioning and Health

Heat is the primary weather-related cause of death in the United States. In the U.S., an average of 658 people died per year from 1999 to 2009 due to exposure to excessive natural heat. Thankfully according to David Hondula, a professor at the School of Geographical Sciences and Urban Planning at Arizona State University1, the number of people that die from heat related causes has decreased over the last decades and this is primarily due to increased use of air conditioning and improved health care.

Our awareness of the importance of indoor air quality has exploded since the corona virus pandemic but for those who have asthma and allergies, indoor air has always been a priority. Indoor air quality has a significant impact on asthma, allergies and other atopic conditions and every year poor indoor air causes more hospital admissions for those with asthma. Both asthma and eczema episodes can flare with changes in temperature and humidity so health experts recommend maintaining a comfortable indoor environment with fairly constant temperature and humidity levels. This is where air conditioning comes in and can significantly improve asthma and allergies.

Interestingly, it has been shown that on those days when outdoor air pollution is high, the cities that have more air conditioner use have less hospital admissions for lung and heart problems. Other studies have shown that children that sleep in non-air conditioned rooms have more asthma and allergy symptoms.

The positive impact of air conditioning on health is even greater when the air conditioning is combined with air filtration. Air filtration with an effective filter can remove VOCs, cigarette smoke, some viruses and allergens such as pet dander and dust mite allergen from the air.

From the benefits to our mood to the improvements to our health, the decision to invest in an air conditioning system may be a no-brainer. Now its time to consider your options . It could be that you don’t want the hassle of installing a central unit. Or the cost. It could be that your existing central system is struggling to maintain a comfortable temperature and needs a little help, particularly in one or two rooms. Or maybe a window unit isn’t an option for you due to building regulations or design limitations. A portable air conditioner is therefore an attractive option.

portable air conditionerWhat is a Portable Air Conditioner?

A Portable Air Conditioner (PAC) is a standalone air conditioning unit that looks like mini fridge or tower fan. It usually has wheels to allow it to be moved from room to room. A PAC has a hose, much like a dryer, that must be vented out a nearby window (though some models can also be vented into a drop ceiling or through a wall). And it needs to be plugged into a power point.
A portable air-conditioner works by removing the warm air from your room, cooling it using a refrigerant and pushing this cool air into the room. It has a built-in thermostat to ensure a consistent temperature. Many also dehumidify the air, by either a second vent hose or using a water reservoir.

What do I need to consider?

Size of your room
This a good starting point because if your room is very large, then maybe a portable air conditioner isn’t the best choice for you. You may be able to find a unit capable of cooling your large area, but the cost may be prohibitive. Instead, if you have the ability to window mount, consider a window unit.

Choosing the right size unit for your space is critical to success. The cooling capacity of an air conditioner is generally measured in British thermal units (BTUs), a measurement of how much heat a unit can remove from a space per hour. Portable air conditioners use this unit to measure their cooling power, so the higher the BTU rating, the larger the room an air conditioner can cool. On average, an AC unit needs about 20 BTUs per square foot of living space to keep things cool. Don’t be tempted to just choose the most powerful unit, as this can lead to its own problems. An oversized unit will reach the demanded temperature too quickly, and will lead to short-cycling and premature breakdowns. On the other hand, if you choose too small a unit, it will have to be run on full power to keep up with demands and your energy bill is not going to be pleasant.

Use the following guidelines to determine the portable air conditioner capacity that your space requires. These calculations assume that you have standard 8-foot ceilings.
7,500 BTUs will cover 150 sq. ft. x 8-ft. ceiling = 1,200 cubic feet
9,000 BTUs will cover 200 sq. ft. x 8-ft. ceiling = 1,600 cubic feet
10,000 BTUs will cover 300 sq. ft. x 8-ft. ceiling = 2,400 cubic feet
12,000 BTUs will cover 400 sq. ft. x 8-ft. ceiling = 3,200 cubic feet

Then, factor in some other variables

  • Climate: hotter climates need more cooling
  • Number of windows: a lot of windows means a space will need more cooling
  • Occupancy: if there a lot of people, temperature will rise
  • Heat generating appliances: does your room have many other appliances in it that generate heat?

Type of window

Most portable air conditioners can be easily vented through traditional sash windows (double-hung windows), using the window kit accessories that are provided with the unit. These same accessories can usually be used for venting some models of portable air conditioners through a sliding window as well.
Venting portable air conditioners through sliding glass doors is much more complicated than simple window installations. If this is what you intend to do, get some advice as you may need to use two kits and screw them together.
Though some people have gotten creative and fashioned their own invention, unfortunately, there are no portable air conditioner units with a window kit that will fit a casement window. If you are determined to have a portable air conditioner but cannot vent it through a window, then there is an option to buy an evaporative model that uses a reservoir of water instead of a hose. They tend to be bulkier so less portable so consider your needs carefully.

smart portable air conditionerSmarts

More and more of our home appliances are becoming smart. If your portable air conditioner is smart it will have Wi-Fi to connect to a mobile app, allowing you to control it remotely. Very handy if your routine isn’t a routine at all and you regularly arrive home unexpectedly and want the luxury of an already cooled room.


  • Timer: will let you set cooling to start or stop when you need it.
  • Remote Control: allows you change the settings from the comfort of your sofa
  • Auto: this has the option to set the unit to cool on its own according to desired temperature.
  • Oscillation/Fan: Some portable air conditioners also oscillate like a room fan, helping move the cool air around the room.
  • Sleep/Night mode: This reduces noise by running the compressor and fan more slowly. Often the target temperature will increase automatically across the night so that you don’t wake up freezing cold.
  • Reverse cycle: you can also find portable units in reverse-cycle – meaning they can cool your home in summer and heat your home in winter.


Some portable air conditioners double up as a dehumidifier. This could be useful if you want to dehumidify a damp cold room in winter as well as cool down a hot room in summer. If you’re primarily after a dehumidifier though, best to stick with purely a dehumidifier because a combined unit can work out expensive. Excess humidity and vapour makes a room stuffy and uncomfortable, and can also lead to the growth of mould and mildew. The dehumidifying feature removes this dampness from the air, not only raising the comfort factor, but improving the indoor air quality. This feature is an especially good option for people with respiratory issues and allergies.

Is your bedroom cousin you health issues? Allergy StandardsAir purification and air filtration

We are all now very aware of how important indoor air is to our health. Breathing in clean air is about as fundamental as we can get when it comes to health. Harmful particles in our indoor air include bacteria, viruses, allergenic particles such as animal dander, pollen, mold and dust mite, particles released by cooking and burning fuel, cigarette smoke, volatile chemicals emitted from paint and cleaning products and particulate matter from outside. Poor indoor air quality can be particularly harmful to vulnerable groups such as the very young and old, and those suffering from chronic respiratory diseases such as asthma. By investing in a unit that also cleans the air, you’ll be making a wellness-focused change.
Almost all portable air conditioners come with a pre-filter, which reduces large microbes, dust and pet hair but the cleaning effect is fairly minimal as it will only capture the largest particles. For effective air purification, the unit must have a filter such as an ionising filter or use other methods such as electrostatic purification or UV purification. Filtration is the process of removing particles – like allergen, pollutants, dust – from the air using, for example, a carbon filter or best of all to remove allergens and tiny particles, a HEPA filter.

Moisture control

If your portable air conditioner has a water collection tray or also functions as a dehumidifier, it is important to ensure that this does not lead to mold growth, which can then be spread to the air in the room by the air conditioner. Check that your portable air conditioner is designed to prevent this, and follow all cleaning instructions that come with the product.

What are the advantages of a portable air conditioner?


Compared to other systems, a portable unit is very affordable. Small, personal models can cost as little as $50, but be careful – for a unit that will cool an entire room, you will need to spend at least $200. The large and more powerful the unit, the more you’ll pay.

Easy to Install

You will be able to install the unit yourself, no professional needed so no extra cost. All units will come with a venting kit and the tools you will require.


Great to have the flexibility to move it from room to room or even room to RV or to a second home.

Excellent option if renting

If you are renting your home and can’t install an alternative system, a portable unit is great. They are also perfect for student accommodation or an RV.

Health Benefits

Cooler, drier air means less mold and damp in your home and a better, healthier indoor environment. If you opt for a unit with an effective air cleaner, then the benefit increases as pollutants and allergens will also be removed. Look for independent certification for the most effective filters and purifiers.

What are the disadvantages of a portable air conditioner?


A portable air conditioner has a compressor motor and a fan, so it will make some sound while running. They are designed for small spaces so usually this noise isn’t overly intrusive. People that experience a very noisy portable air conditioner have often chosen the wrong size for their room and as a result the unit is being forced to work at maximum capacity at all times.
Positioning the unit on a carpet or rug to deaden noise from vibrations will help. Or run the portable air-conditioner in the morning to avoid having it at maximum power for long periods during the day. No air conditioner will be completely silent though, even in sleep mode, so manufacturers often recommend pre-cooling rooms before you go to bed, rather than attempting to sleep with an air conditioner running.

Energy Usage

Relatively speaking, portable air conditioners do use a lot of energy. The combined energy efficiency ratio (CEER) is the standard rating for air conditioners. It’s based on the amount of energy used while the unit runs, as well as when the air conditioner is on standby. Generally, the higher the rating, the better efficiency and this also means lower energy bills. The sleep/timer/auto modes available on some units will help reduce energy requirements and running costs.

climate change portable air conditionerEnvironment

Energy usage and refrigerants are the two area of concern when it comes to the environment and climate change. Refrigerants are liquids used in air conditioning to absorb the heat. They damage the earth’s ozone layer as well as contribute greenhouse gases to the atmosphere. A properly maintained unit shouldn’t release harmful substances into the atmosphere, though some are released when the unit is manufactured and when it is disposed of. Proper maintenance of the A/C units, EPA-certified reclamation or recycling of the refrigerants, and use of energy efficient units can help reduce the harmful impact of air conditioning on the environment.

Bulky and heavy

Although the units are designed to be portable, some of the bigger models are heavy and bulky and do take up space. If you are planning on moving your unit a lot, opt for a lighter model and avoid the heavy duty ones that can weigh up to 100lbs.
The unit will need some space around it so the circulation of the cool air isn’t blocked, so best not to place them pushed against a wall or furniture. Generally, 50cm is a good distance. Also, for optimal efficiency, the exhaust hose can be up to 7ft long and as straight as possible because kinks can reduce the effectiveness.

One room only

Due to its one directional air flow, only one room will be cooled and in general portable air conditioners work best in smaller areas. The cooled air will not travel down the hallway or through narrow doorways. To cool a larger area, say 70-80sqm and above, investing in a more permanent air conditioner, such as a split-system or window air conditioner, is your best option.


Portable air conditioners have air filters to keep circulating air clean and ideally this should be cleaned out every two weeks to maintain the best performance. The filters are easily washed with warm water and detergent.
If it has one, you’ll also need to drain your unit’s water collection tray fairly often. This prevents the growth of mold. Dual-hose models may not collect water if they vent most of the humidity out a second hose, so check the unit’s care instructions to find out for sure.
That’s it really. A general dusting and wiping down with a damp cloth will keep your unit looking new and working well. Find somewhere cool and dry to store it when you don’t need.

In Summary

So it seems that, pretty much like all things in life, portable air conditioners have their pluses and minuses. A quick assessment of your individual needs will help you make the right decision for you. If you require cooling of a relatively small space, want the freedom to move your appliance to another room and don’t want any installation hassles, the a portable air conditioner is for you,. All you need to do is sit back and enjoy the cooled, drier air that has the added benefit of contributing to a healthy home

Air Conditioners and the indoor environment

Air quality is a term that incorporates a range of features that can include particulate matter, allergens, chemicals (VOCs) and relative humidity. The concentration and impact of these must be controlled in order to ensure a healthy indoor home environment. Those with asthma and allergies in particular can be affected by the quality of indoor air.

Healthy Indoor Air

There are a range of approaches that can be taken in order to support a healthy indoor environment. Air conditioners are one of these and can play a significant role in good indoor air quality. Greater asthma morbidity – specifically a larger number of hospitalizations, wheezing episodes and night symptoms due to asthma – have been associated with the presence of moisture, mildew and cockroach allergen in homes1. Air conditioners provide a dual function of controlling temperature and relative humidity in home environments, as well as potential removal of allergens.

Temperature extremes can have a negative impact on those suffering from asthma and allergies. While the mechanism of action of temperature on asthma and allergy exacerbation has not been absolutely defined, the relationship that temperature has to relative humidity is likely to play a role. A 2013 article reported on increased emergency department admissions for childhood asthma during periods of extreme temperature2 and higher temperatures have also been associated with lower lung function in children with asthma3. Control of temperature to median ranges is therefore essential and ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) recommend a temperature range of 68-75°C (20-24°C) in winter time and 73-79°F (23-26°C) for the summer time4.

Relative humidity (RH) is in essence is a measure of how much moisture is in the air, and is related to the temperature of the air. It is important in the context of its impact on the body and on the surrounding environment. RH of 30-60% is a comfortable physiological range and is recommended by ASHRAE5; if RH starts to drop below 30% however it can have a negative impact on a range of physiological functions. Some viruses can survive for longer in dry, cool conditions and lower RH levels can result in drying out of the eyes and mucous membranes. These two impacts combined can cause a greater risk of infection6. Very dry air can also result in dry skin, worsening of eczema and irritation of the airways.

As RH levels increase above 60%, the potential detrimental impact is more from an environmental perspective. As RH increases, it creates a more suitable environment for dust mites and mold to grow. Dust mites thrive at RH levels above 70% and controlling RH to below 60% is essential to prevent their proliferation. Generally, ideal mold growth conditions are above 70%, however any RH level above 55% will allow mold to grow. For those with asthma and allergies, controlling exposure to allergens is essential and ensuring unfavourable conditions for mold and dust mites is essential.

The ideal relative humidity for comfort and health is between 40-50%, an air conditioner is best suited to provide this control.

Asthma and allergies

Use of air conditioning can help mitigate asthma and allergy symptoms caused by poor air quality. A 2011 study found a stronger association between asthma and allergy symptoms among children sleeping in non-air-conditioned homes, suggesting air conditioning in the bedroom may modify the health effects of indoor air pollutants7. In an earlier study, on days with high concentrations of particulate matter, cities with a high prevalence of air conditioner use report fewer hospital admissions for respiratory and cardiovascular disease compared with cities with lower air conditioner use8.

In addition to temperature and RH control, most air conditioning systems will have a particle removal system in place. While it is not the primary function of air conditioners to remove allergens, many air conditioners do incorporate filters that are capable of this. In this context, change of filter should be considered as allergen may have built up on the filter during use. The types of filters that an air conditioner may have, include:

  1. Coarse filter: the most basic filter is a coarse filter for removal of larger particles such as large dust particles and pet hair that may damage or clog the air conditioner unit. These filters are generally composed of plastic or polypropylene.
  2. Activated carbon filter: carbon filters can absorb contaminants (like VOCs) and some odors from the air. They have very porous structure and the compounds become trapped; over time the carbon filter will eventually become full, and will need to be replaced.
  3. Electrostatic filter: as the particles in the air pass through the electrostatic filter, they receive a charge, this allows them to be stuck to metal plates in the air filter, preventing them from being released out of the air purifier. The principle of electrostatic filtration can also be applied to media based filters, giving them an added advantage for filtration.
  4. Media based filter: as the air is drawn through the filter, the pore size of the filter stops specific sizes of particles being able to pass through the filter. The smaller the particle size, the more energy that is required to draw the air through the filter. Some of the most effective media filters, are HEPA filters (high efficiency particulate air) which can trap extremely small particles. This type of filter can remove a minimum of 99.97% of airborne particles of 0.3 microns or greater which will address the majority of indoor air contaminants such as dust, pollen, mold and bacteria9.

If the air conditioner does filter the air, the particle size it retains should be determined. Filters are generally ranked according to the particle size that they will trap, in line with this, the smaller the particle size, the more power that is required to draw air through the filter. Over time filters will need to be replaced as they become clogged and, in a similar way to vacuum cleaners, the exposure of a sensitive individual needs to be considered when establishing a removal and replacement protocol.

The efficacy of a filter is dependent upon the integrity of the seals into which it is placed and when such a system is put in place, you should ensure that replacement of filters does not result in compromising the filter system. In general filters which can filter out a minimum of 10µm (this is 1/100th of a millimetre or less than 1/1000th of an inch) are appropriate for allergen removal.

While media based filters can provide very effective particulate removal, as outlined above, other technologies may also be used in air conditioner units (eg electrostatic technology and carbon filters). Users should always ensure that there is validated data to support the efficacy of any technology that they are to reply on.

Certification of Air Conditioners
Selection of the right air conditioner can be difficult, and there are a number of Certification Marks that can help you make the right selection.
The Association of Home Appliance Manufacturers (AHAM), established more than 50 years ago, represents the appliance manufacturing industry by through leadership, education and advocacy. Part of this role involves setting standards for the performance of these appliances, including air conditioners. The AHAM air conditioner standard measures specific characteristics that an air conditioner should achieve, mostly based around maintaining relative humidity in a standard room sized chamber.

asthma & allergy friendly® – The asthma & allergy friendly® Certification Program is operated by Allergy Standards Ltd in collaboration with the Asthma and Allergy Foundation of America (AAFA), Asthma Canada and is also operated internationally through a global certification mark. Air Conditioner certification is based on the impact on the indoor environment for those with asthma and allergies. The standard measures for the performance of air conditioners in a room sized chamber and addresses control of temperature and relative humidity, disturbance and removal of allergen, ozone production and general operation such that those with asthma and allergies should be appropriately protected.

Air conditioners can play an essential role in an allergy management plan. However selection of the right air conditioner, with effective relative humidity control is essential. Filter efficiency, size of room, practical operation of machine and alternative technologies are all things that need to be considered. Prior to purchase of an air conditioner for your home, it is important that you educate yourself as much as possible in order to make the right choice.

  1. Bonner S, Matte TD, Fagan J, Andreopoulos E, Evans D. Self-reported moisture or mildew in the homes of Head Start children with asthma is associated with greater asthma morbidity. J Urban Health. 2006; 83:129-37
  2. Xu Z, Huang C, Hu W, et al. Extreme temperatures and emergency department admissions for childhood asthma in Brisbane, Australia. Occupational and Environmental Medicine 2013;70:730-735.
  3. Li, S, Baker, PJ, Jalaludin, BB, Marks, GB, Denison, LS and Williams, GM. Ambient temperature and lung function in children with asthma in Australia. European respiratory Journal 2014 43 (4): 1059-1066.
  4. American Society of Heating, Refrigerating and Air-Conditioning, Inc. ASHRAE Standard, Ventilation for acceptable air quality, 2007, ANSI/ASHRAE Standard 62.1-2007.
  5. ASHRAE Handbook—HVAC Systems and Equipment, 2016; Chapter 22.
  6. Wolkoff, P and Kjaergaard, SK. The dichotomy of relative humidity on indoor air quality. Env Int 2007; 33 (6): 850-857.
  7. Zuraimi MS, Tham KW, Chew FT, Ooi PL, Koh D. Home air-conditioning, traffic exposure, and asthma and allergic symptoms among preschool children. Pediatr Allergy Immunol. 2011;22(1 Pt 2):e112‐e118. doi:10.1111/j.1399-3038.2010.00992.x
  8. Janssen NAH, Schwartz J, Zampbetto A, et al. Air conditioning and source-specific particles as modifiers of the effect of PM10 on hospital admissions for heart and lung disease. Environ Health Perspect. 2002;110:43-9
  9. Environmental Protection Agency [online] https://www.epa.gov/indoor-air-quality-iaq/what-hepa-filter-1 accessed June 2020.



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ASL Helps Shape the Future of Healthy Buildings at NeoCon and Design Days 2023

16 June 2023

ASL had a hugely successful few days at NeoCon and Design Days 2023 in Chicago

ASL to Share IAQ Expertise with the Design Industry at NeoCon and Design Days 2023

2 June 2023

We are looking forward to bringing our expertise in indoor air quality to NeoCon this month to help shape the built environment today and into the future.

ASL to Share New Research on Textile Flooring at EAACI Congress 2023

1 June 2023

ASL is excited to share the results of our new research on textile flooring at the EAACI Congress 2023

Dr. John Ryan delivered an impactful keynote speech at Pulire 2023

17 May 2023

Dr. John Ryan, CSO at ASL, addressed the Importance of indoor air quality and ESG needs in his impactful keynote speech at Pulire 2023

Dr. John Ryan at ISSA Pulire 2023, Addressing the Importance of Indoor Air Quality and ESG Needs

5 May 2023

Dr. John Ryan will speak at ISSA Pulire 2023 with a talk entitled 'Cleaning For Purpose Not Just Appearance.'

ASL Bring Indoor Air Expertise to BAU 2023

25 April 2023

BAU 2023 was a great opportunity for ASL to bring their expertise in indoor air quality to Europe, meet new clients, and catch up with Tarkett at their busy booth

You’ll Start Tracking Home Health Like You Track Heart Health; Dr. John McKeon tells Well+Good Why

16 December 2021

Dr. John McKeon, CEO of Allergy Standards, gives expert advice on tracking home health and why it makes perfect sense

Why regular laundry washing is important to maintain a healthy home environment

28 October 2021

Many people can be allergic to dust mites, pet dander, and other allergens that can build up in bedding, clothes, and other washable items at home. Taking care of these items by washing them regularly is a fundamental part of maintaining a healthy home environment.

NBC News Consults Dr. John McKeon

14 October 2021

In this NBC News article, digital editorial intern for Select, Zoe Malin seeks expert advice from ASL CEO, Dr. John McKeon, on indoor air quality and air cleaners.

Dr. John McKeon on Healthy Indoors Live

23 August 2021

Watch our CEO Dr John McKeon and President & CEO of the Asthma and Allergy Foundation of America, Kenneth Mendez, on Healthy Indoors Live with Bob Krell for a very interesting dive into the significant role a healthy indoor environment plays in our overall health & well-being.