1. Ensure the portable air cleaner is sized correctly for the room area. Measure the square area of the room and confirm the model of air purifier is specified for a range which includes your room size.

2. Ensure the clean air delivery rate (CADR) of the portable air purifier will be effective for the size of the room. The higher the CADR, the larger area it can serve. Measure the square area of your room and check that is provides the recommend minimum CADR per room size, being at least 2/3 of the rooms floor size based on a 2.5m ceiling. The CADR should be higher for larger ceiling heights.

3. Ensure the air cleaner has superior filters. Confirm the air purifier is equipped with a high efficiency particulate True HEPA air filter (HEPA-13) to effectively filter out small particles. HEPA filters are best for pollen, dust, pet dander, and some bacteria and viruses.

Pre-filters are also recommended as they prevent large airborne debris such as pet fur and clumps of dust from entering the air purifier. This greatly extends the lifespan of the HEPA filter and ensures that the HEPA filter has more capacity in trapping microscopic particles.

To tackle gas and odour issues indoors, activated carbon are required. They capture VOCs through the adsorption process where VOCs are attached to the surfaces of the activated carbon atoms within the filter. Carbon filters are great for odours, chemicals, and VOCs.

Cold catalyst filters are a good partner to activated carbon filters as they absorb and decompose formaldehyde in the air and tiny floating dust particles. They also help in the removal of other harmful gases such as Benzene, ammonia and TVOC. Our cold catalyst filters are not photocatalyst type filters, which have a number of inherent issues with secondary pollution and bacteria.

4. Avoid air purifiers that contain electrostatic precipitators, ionizers, UV-C lights, or plasma air cleaners, which can produce ozone, which is a lung irritant. Our models do not use either of those technologies.

5. Consider cost: Smaller units can cost as low as $150 and larger units can cost $1000 or more. Compare features, purifications rates and filtration types against the total cost of the device. Replacement filters are an added maintenance cost to consider, so ensure that the replacement filter costs are reasonably priced.

6. Consider noise levels: EH&S recommends purchasing a portable air cleaner that produces sound at a decibel level (dB) under 60 dB in auto mode because higher sound levels may be distracting unless they are a larger unit in an area with higher foot traffic.

7. Consider physical size of the unit: Consider the dimensions of the unit and have a plan for placement in the room or office.

8. Identify the additional features which you would prefer for your air purifier, which may include:
• Remote control
• On/off timer control
• Sleep Mode (low power and low sound)
• Filter replacement indicator
• Speed control options (AUTO- 1-2-3 etc)
• Wheels
• Integrated air sensors (particle, gas) and display
• Energy consumption
• Child Safety Feature
• Wifi Control (via mobile Phone)
• Warranty

Correct Sizing

Choosing an Air Purifier? Room Size, CADR, CCM and Air Changes per Hour

Air purifiers have varying efficiencies depending on the size of the room it needs to clean and how many cubic meters per hour it can process. The rate at which they filter the entire volume of the room matters and so does their long-term performance. The terms associated performance measurements can be confusing so here is a good starting guide.

What is a CADR rating?

Clean Air Delivery Rate (CADR) is a rating system that can help determine the effectiveness of an air purifier based on how many cubic meters or cubic feet per minute (CFM) of particulate matter it can filter per hour. Generally speaking, the higher the CADR value, the faster the air purifier is at processing air. According to the US based Association of Home Appliance Manufacturers, an air purifier should have a CADR rating of at least two-thirds of your room’s square footage.

There are two CADR values, each focusing on a specific airborne pollutant: particulate (dust/pollen) and gas (formaldehyde/smoke).

CADR does not test for air purifiers’ performance against ultrafine particles. The three contaminants that CADR tests for (dust, pollen, and smoke) are on the larger side of the spectrum of airborne contaminants that are commonly filtered, ultrafine particles smaller than 0.1 microns make up 90% of the particles found in the air and harmful biological aerosols typically come in these sizes. Hence the CADR system has its limitations and it should not be the only factor selecting the right Air Purifier.

What is ACH ?

Air Changes per Hour (ACH) tells you the number of times an air purifier can filter the entire volume of air in a room within the span of an hour. You can use this to compare the effectiveness of air purifiers. A minimum ACH rating of 4 is a good baseline to remember when choosing an air purifier. Hence ACH is dependent on the volume of the specific room. ACH = Volume / CADR.

Recommended Air Changes Per Hour Based on Room Type
Room Type	Location	Recommended ACH
Residential	Basements	3-4
	Bedrooms	5-6
	Bathrooms	6-7
	Family Living Rooms	6-8
	Kitchens	7-8
	Laundry	8-9
Officers	Business Offices	6-8
	Lunch Break Rooms	7-8
	Conference Rooms	8-12
	Multiple desk areas	10-14
	Smoking Areas	13-15
Restaurants	Dining Area	8-10
	Food Staging	10-12
	Kitchens	14-18
	Bars	15-20
Medical	Patient Room	6
	Triage	12
	Isolation Room	12
	Emergency Room	12
	Dental Room	10
	Operating Room	15-20