​​Sanctuary Air SA-250 Series

How to choose an air purifier

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How to choose an air purifier

Indoor Air Pollution Fact Checks

Indoor Air Quality Measurements

"to measure is to know"

William Thomson Kelvin, Mathematical Physicist, 1824 - 1907

​​Air Quality

What is PM1 and why is it harmful?

You may have heard of PM2.5, that's Airborne Particulate Matter 2.5 microns or smaller? Well PM1 air pollutants are are smaller again and are considered to be most harmful because it is when particles measure between 0.25 to 0.5 microns in diameter, they have a closer relationship to human health, especially an increased risk of deadly diseases such as heart attacks and lung cancer.

If you are wondering where they come from, it's mostly from combustion; road traffic exhaust, and smoke from industrial processes, wood and tobacco. It is the size of PM1 that makes them harmful; small enough to by-pass the defense of our lungs & alveoli. In doing so, they damage cardiovascular tissue and the inner walls of arteries, and once in our blood stream, PM1 can migrate into other organs including the heart and brain. 

An air filter that effectively separates PM1 from the air we breath will not only protect people from serious health problems, it will also help with general well-being and productivity by preventing viruses from spreading. Sanctuary Air HEPA filters efficiently take care of PM1 and that is very good news if you live near a busy road, an industrial zone, smoke, or want to prevent the next airborne cold or flue virus from spreading through your home.

Is it true that cleaner air improves cognitive skills and increases productivity in study and work?

Yes, it has been proven in several double blind studies.

Indoor air is polluted with hundreds of volatile organic compounds (VOCs) from construction materials, furnishings, office equipment, cleaning products, carpets etc. Indoor air is also polluted with excess CO2 and CO from human respiration and from indoor combustion, for example from gas appliances. It turns out that even at commonly experienced levels, VOCs and CO2 have a profound affect on cognitive functions.

A 2015 double-blind study[1] measuring nine cognitive domains, found that people who work in offices with reduced levels of indoor VOCs and CO2 on average score double those who work in offices with typical pollutant levels. Crucially, participants scored 131%, 288% and 299% higher respectively in the key areas of crisis response, strategy and information usage. Usha Satish, professor, SUNY Upstate University states  "these are critical decision making parameters linked to optimal and productive functioning". Joseph Allen, assistant professor, director of the Healthy Buildings Program at the Harvard Center for Health and the Global Environment, states “These results suggest that even modest improvements to indoor environmental quality may have a profound impact on the decision-making performance of workers.”

What is the CADR rating system and why is it used to compare the performance of portable air purifiers and not whole house air purifiers?

CADR (Clean Air Delivery Rate) is a way of comparing the effectiveness of different air purifiers. It is determined by a standardised test that calculates the maximum room size in which a portable room air purifier (on maximum fan speed) can achieve 80% reduction of airborne particles. The 80% target requires the room air purifier to deliver the equivalent of 5 clean air changes per hour in that room size.​ The equivalent CADR of a portable air purifier is always less than the purifier's actual air delivery rate owing to the purifier's air flow pattern and filter quality. The CADR test doesn't apply to whole-house systems because:

1) Whole house systems have a more effective air flow pattern. In the case of portable purifiers, air flows in a shorter circuit because the inlet and outlet are in close proximity and within the same room; some already clean air is drawn back to the purifier before completely mixing with room air, meaning the purifier has to move more air to remove contaminants. In contrast, a ducted system has multiple outlets that are well separated from the air intake and are in separate rooms. Air is well mixed by time it reaches the air intake, meaning a ducted system will collect more contaminants per unit volume of air moved. 

2) Portable purifiers need to overcome a higher pollutant load per room due to airborne particles that infiltrate from adjacent rooms, whereas with a multi-room ducted system the adjacent rooms are also being cleaned, so the pollutant load to clean, per room, is reduced.

3) A whole house system has the option of adding ventilation air to the air intake. Doing so introduces positive pressure and a powerful performance boost.

4) Every Home is different.

In essence, a whole house purifier with a genuine medical grade HEPA filter will have distinct advantages over portable air purifiers, advantages that can be verified with laser particle counter measurements. Add ventilation to the purifier's air intake, and the resulting positive pressure takes air quality to a level that can only be achieved with a whole house ducted air purifier. ​

HEPA filters are specified at 0.3 microns. Can a HEPA filter remove particles smaller than 0.3 microns?



HEPA Filter Efficiency Vs. Particle Size


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 03 8560 2111

Quality Australian Made Ducted Air Purifiers

  Purely for health

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Manufacturer of premium quality central air purifiers

FILTRATION OF AIRBORNE MICROORGANISMS: MODELING AND PREDICTION, W. J. Kowalski, M.S., P.E., ASHRAE Student Member, W. P. Bahnfleth, Ph.D., P.E., Member ASHRAE, T. S. Whittam, Ph.D., Copyright © 1999 by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.


How do I purchase a Sanctuary Air purifier?

​Do you offer after-sales service?

Where do I purchase replacement filters

How do I know when to replace a filter?


Can a whole house air purifier share the same ducts and outlets as Ducted Gas or Ducted R/C systems?

Can a whole house air purifier transfer air from heated or air conditioned rooms to other rooms?

Is it true that a ducted air purifier can save on heating and cooling costs?

What are the benefits of owning a whole house air purifier?

Why include outdoor air in the purifier's air intake?

Do your air purifiers release any harmful by-products?
What are "Mechanical Filters"?

Why do some salesmen claim whole house air purifiers don't work?

​Do Whole House Air Purifiers really work?

Air Quality

How does cleaner air improve cognitive skills and increase productivity in study and work?

What is PM1 and why is it harmful?

What is the CADR rating system and why is it used to compare the performance of portable air purifiers and not whole house air purifiers?

HEPA filters are specified at 0.3 microns. Can a HEPA filter remove particles smaller than 0.3 microns?


How do I purchase a Sanctuary Air purifier?

a)Contact usby phone or email to express your interest.

b) We will arrange a time for an obligation free in-house assessment and quote.

c) Once you are satisfied with the package, we arrange for our Sanctuary Air approved installer to visit at your convenience. It takes a single working day to complete the task. 

Do you offer after-sales service?

Yes, we are dedicated to keep your system running. Sanctuary Air provides phone and email support Australia wide, and we provide on-site service in SA and VIC. We also provide an on-site filter change service for those who prefer us to do it for them. 

Each system comes with a 3-year parts and labour warranty, however our purifiers are constructed from the most reliable components we could find anywhere. To date we have not had one purifier break down.

Where do I purchase replacement filters
Contact Sanctuary Air for all replacement filters. We have an Australia-wide freight service at reasonable rates. We also offer a filter replacement service where we do it for you.

How do I know when to replace a filter?
Sanctuary Air filters are large in size to keep ownership cost down. They are tolerant of high dust loads, but as a general rule:

Pre-filters should be replaced every 6 to 12 months depending on air quality in your location. In many cases the interval is 12 months. We recommend that the first filter change is done by us, this way we assess the rate of dust loading in your location and determine the most economical filter replacement schedule for you going forward.

HEPA filters should be changed every 3 to 5 years. When we replace your first pre-filter we run a HEPA test to measure the rate of dust loading from which we can predict the most economical replacement interval for your location. We recommend HEPA filters are replaced by us to ensure the filter is not damaged and that the seals are perfectly intact but they can also be changed by home owners with careful handling.


Can a whole house air purifier share the same ducts and outlets as Ducted Gas or Ducted R/C systems?
Yes. We can connect to your existing outlets and pass on the cost savings to you. 

Can a whole house air purifier transfer air from heated or air conditioned rooms to other rooms?
Yes absolutely! Whether you have a wood heater, wall split R/C, or gas room heater, we can locate the purifiers indoor air intake near your primary heating/cooling unit, to help spread the comfort further. In the case of wood heaters, the system also removes indoor smoke.

Is it true that a ducted air purifier can save on heating and cooling costs?

Yes, mostly on heating cost. How it works is the purifier can select intake air from inside, from outside or from the roof space.

Air from the roof space is often 5 to 10 degrees warmer than outside air, and there are many days throughout a year where it can help warm a cold home. In Melbourne for example the heating season can extend from April to early November. It is during the shoulder season that the heating effect is most beneficial and on cold sunny spring or autumn days, heating can even continue for an hour or two after dark.

During warm months on the other hand, outside air can provide overnight cooling, and depending on your climate and weather, it can delay the need for air conditioning by a few hours. The cooling function is not as powerful as the heating function but it does bring some morning freshness into a home during the shoulder season. 

When the weather is right, these functions can reduce energy costs. Of course they are not a replacement for conventional heating or cooling appliances.

What are the benefits of owning a whole house air purifier?

The benefits belong to two main categories. 1) Home maintenance costs (cleaning, heating&cooling, property protection such as avoiding moisture damage, mould, reduced wear&tear), 2) Health (reduced health risks and costs, improved productivity).

We created a spreadsheet to quantify the benefit in $ p.a. It's hard to quantify health because this varies so much with each individual and household, so we left health entries blank. Using conservative estimates for every category but health, the return on investment is still attractive; the system pays for itself.

Just a few examples:

- expect to half the time you spend dusting and vacuuming.

- with less dust, expect less abrasion and wear on floors and valuables

- expect 0.5 fewer sick days per year (from European studies on worker performance - cleaned air Vs. typical indoor air)

- it is unlikely that you will need to pay professional duct cleaners any time soon

- plus many more benefits...

If you would like to know more, please Contact Us and ask for our cost benefit spreadsheet.

Why include outdoor air in the purifier's air intake?
Air filters are very efficient at reducing airborne pollutants, such as fine particles, VOCs and odours, but there is no air filter that can replenish Oxygen or remove CO2 exhaled from people or CO from gas appliances. A total clean air solution therefore must include sufficient ventilation. There is no alternative.

Modern air tight buildings often suffer from inadequate ventilation especially during calm weather. Apart from CO2, CO and synthetic indoor chemicals, trapped moisture can also lead to potentially lethal mould problems and costly building repairs.

A four person home needs a steady ventilation rate of about 50 L/s to prevent CO2 levels from exceeding 600ppm. The trouble with passive ventilation is that it isn't steady and there are times when air gets quite stagnant.  We usually include at least 20% ventilation air in the purifier's intake, with the option to open up ventilation to 100%, for example during summer nights.

Do your air purifiers release any harmful by-products?

No. Sanctuary Air Purifiers use purely "mechanical" methods to remove air pollutants.  Mechanical filters produce no unwanted by-products. They are low in maintenance and are proven reliable. It's the reason they are used in critical air quality applications such as hospital operating theaters, museums and premium public buildings. 

We did research electronic filters and photo-catalytic converters as lower cost alternative methods. Electronic filters do need regular maintenance and due to the way they work, can deposit grime on walls and furnishings. Further, as these alternative products do produce ozone and chemical by-products, we instead chose a mechanical filter set; Totally safe, reliable, effective and very low in maintenance.

What are "Mechanical Filters"?

Mechanical filters physically capture and trap air pollutants. This is in contrast with other filter types that "zap" pollutants or charge pollutants using high voltages.

A mechanical filter set consists of three parts

1) A low cost Pre-Filter to collect medium and coarse particles down to about 2 microns. It prolongs the life of the HEPA filter.
2) A Medical grade HEPA filter to capture fine and ultra-fine particles, removing harmful PM1 particles and any smoke.​ 
3) A Molecular filter usually containing broad spectrum activated carbon and other selected adsorbents to capture odours and hundreds of volatile organic compounds (VOCs). 

Sanctuary Air filters are large in size for low maintenance and to reduce ownership costs. Large filters are also energy efficient, providing electricity cost savings. For more information about our filters please link to our Replacement Filters page.

Why do some salesmen claim whole house air purifiers don't work? 

It's probably because they want you to buy a portable air purifier instead. It's easy to demonstrate that this claim is complete nonsense by taking measurements with a laser particle counter. When it comes to air purifiers, there is nothing better than a whole house HEPA air purifier. 

​​Sanctuary Air SA-250 Series

purely for your health

​Indoor Air Pollution Fact Checks

Yes, very very much smaller. Genuine HEPA filters can remove particles down to 0.001 microns by a well studied process called "Diffusion". The diffusion effect applies to particles that are smaller than 0.4 microns. These particles, due to their light weight, pursue an irregular path that can digress from the direction of air flow. Although these particles can be much smaller than the spaces between filter fibers, the irregular, or diffuse, path raises the probability the particle will collide and attach to HEPA fibres. See Figure 1.

HEPA filters are specified at 0.3 microns for a very good reason. Particle sizes ranging from 0.1 and 0.4 microns are the most difficult to capture because those particles still have enough mass to make the diffusion effect relatively weak. As such, specifying at 0.3 microns provides a meaningful description of filter performance because it measures near the weakest point of the filter.


If a filter is not specified in this range, then it could mean the filter falls short of HEPA performance.

How well do Whole House Air Purifiers work?

Spectacularly well. We set up a laser particle counter in the living room of a suburban home and measured air quality before and after running our Whole House HEPA Air Purifier. After one hour, the concentration of airborne particles from smoke, road traffic, dust, mould etc) was reduced by 95%​

William Thomson Kelvin

Phone 03 8560 2111