Oreck DualMax Air Purifier

A compact electrostatic cleaner that is whisper quiet (at the lowest speed setting) and doesn't require the purchase of any consumables.

Oreck DualMax Air Purifier

Oreck DualMax Air Purifier

If you suffer from allergies, if there are smokers in your home, or if there are obnoxious odours or other pollutants in the vicinity of your home, you might want to consider installing an air cleaner (purifier). While you can install a whole home air cleaner, a portable unit might be just as effective and considerably less expensive. By their design portable units can be moved from one location to another – you might run it in your living room throughout the day, and then move it to your bedroom in the evening. 

All portable air cleaners work in the same basic way. Contaminated air is drawn into the cleaner by means of a fan, the air is cleaned, and then expelled back into the room. There are two main ways in which the contaminated air is cleaned – by passing air through one or more HEPA filters (these are referred to as 'HEPA air cleaners'), or by passing air through one or more non-HEPA filters and electrostatically attaching the contaminants to plates or wires where the particles can be manually removed (this type is referred to as an 'electrostatic air cleaner' or electrostatic precipitator).

The effectiveness of HEPA cleaners is almost entirely determined by the HEPA filter – these filters are known to remove particulate matter down to 0.1 microns with an effectiveness of 99.97%. The effectiveness of electrostatic cleaners, which can range from about 90% to 99%, are dependent on several factors that include the size of the collection plates, the strength of the electrostatic field, the rate at which air flows through the cleaner, and the frequency and diligence owners take to clean the collection plates.

A major advantage of an electrostatic cleaner is that there are no filters to replace (the pre-filters can be washed and reused). The filters in a HEPA cleaner have to be replaced every 6 to 12 months or so (depending on the amount of contaminates in the air), and can cost upwards of $80. However, electrostatic cleaners require regular maintenance, roughly every 2 to 4 weeks, which can be somewhat time consuming. Most also emit ozone into the air, which is a potent lung irritant. Some produce negligible amounts, others produce levels that exceed recommended safety standards.

Fortunately, manufacturers of electrostatic cleaners are constantly making improvements in reducing ozone emissions, and increasing cleaner efficiency. 

I used the Oreck DualMax in my living room over a six week period. The DualMax is a portable electrostatic air cleaner designed to clean the air in rooms up to about 900 square feet. It's a sleek, attractive unit that is fairly compact, measuring about 12" wide, 9" deep, and 18" high. Weighing just under 16 pounds it's easy to tote from room to room. 

The motor consumes just 55 watts – about the equivalent of an incandescent light bulb), which means that isn't going to impact your electricity bill very much even if you leave it running all the time. It has three speed selections (low, medium, high), an odour absorber mode, and a night light. There is a control panel integrated into the top of the unit, and it also comes with a remote control. The unit has a CADR (Clean Air Delivery Rate) of 130 cubic feet per minute (at its high setting) based on a 1600 cu ft room (10' by 20' with a standard 8' ceiling). CADR is a measure of the amount of particulate matter (smoke, pollen, and dust) of a specified size, removed from the air over a defined period of time. In general, a higher CADR value implies greater efficiency. These rates vary considerably, from a low about 50 to over 500. Air cleaners that use HEPA filters use a different measure of efficiency – the MERV (Minimum Efficiency Reporting Value) rating – so you really can't compare CADR values to MERV values.

At the highest speed setting the DualMax takes about 12 minutes to cycle the air in a 200 square foot room (or about 5 air changes per hour), and 55 minutes for a 900 sq foot room (or one air change per hour).


The DualMax isn't a complicated unit. There is a control panel (A) at the top, a built-in odour absorber module (B), a removable pre-filter (C), and the main core of the unit, the removable 'Truman Cell' (D).

It also comes with a convenient remote that provides the same menu as found on the control panel. You can use it to start or stop the air cleaner, select different fan speeds, and turn the odour absorber on and off.

Using an app on my smartphone I measured the low speed setting as 18dB – barely audible; the medium speed at 28dB, and the high speed at 45dB. When I am going to be out of the room for an extended period of time I turned the unit to either the medium or high setting – otherwise I leave it on the low setting. I do find that I can leave the unit on the medium speed while reading or watching the telly, however I find both the medium and high settings too loud whenever carrying on a conversation with anyone.



The pre-filter is a plastic mesh with grid of 5/64" holes, which removes fairly large particles, dust, hair, lint, and the like, before the air reaches the Truman Cell, which handles the very fine particulate matter. It's fairly durable, so you can use a brush to remove the accumulated debris, and then rise it with water. You'll need to let it dry before reinserting it into the air cleaner. There's a convenient 'up arrow' printed on the front spine of the filter so you install it the right way.



The Truman Cell is where the finer dust is treated. It consists of two parts, a frame containing a series of fine wires (called the 'wire assembly', left in photo above), and the Truman Cell itself, which consists of a series of thin collector plates. Both the wires and the plates are electrostatically charged – fine particulate matter, such as dust, smoke, pollen, bacteria, and molds attach to the wires and plates. According to Oreck, the DualMax will filter out particles down to 0.01 micron – the size of dust mite allergens.

You do have to manually remove the accumulated debris by 'carefully' washing both frames. The DualMax comes with explicit instructions on what to do, and what not to do. The wires, in particular, are very thin, and you want to be careful not to break them. If you don't clean the frames regularly, the Truman Cell becomes less efficient – more of the fine particulate matter will pass though the unit and end up back in the air, rather than adhering to the wires and plates.


In the photo above you can see the fine particulate matter built up on the Truman Cell plates. This photo was taken after 4 weeks of use.  Obviously, the amount of build up will vary depending on how contaminated the surrounding air is in a particular environment. After using the DualMax for four weeks I cleaned the frames. It took me about 10 minutes to thoroughly clean both parts of the Truman Cell. I then let the unit completely dry overnight before reinstalling it back into the DualMax.

There is a small brush that comes with the unit. It's perfect for removing larger dust particles from the pre-filter. I was also able to use it to carefully dislodge dust from the wires, and to clean the plates. I first soaked the plates in hot soapy water for abut 5 minutes, used the brush to work away the dust, and then rinsed with clean water.

Of course, when cleaning the air purifier you're exposed to the particulate matter on the wires and plates, so if you have fairly severe allergies then you'll want to wear a dust mask or respirator when cleaning the DualMax.



The odour absorber unit (also referred to as the Helios Shield) is not removable. My understanding is that it contains internal UV (ultra violet) lights that serve to eliminate VOCs (Volatile Organic Compounds) and various odours such as musty smells, cooking odours, pet stench, paint smells, aerosol vapors, and cleaning supply fumes. You can leave it on continuously, or turn it on as needed. As for most ionizers, the DualMax does emit ozone, at a rate of 50 PPM (parts per million) – well below the recommended EPA (US Environmental Protection Agency) daily limit of 70 PPM.

To know how effective any air cleaner is you really need to monitor any improvements to your health after installing one of these devices. I have mild allergies to animal dander and mold, and it seems to me that using the DualMax does reduce my incidence of sneezing and post-nasal drip. To see how effective it might be at handling odours I burnt a 6" stick of and then turned the odour absorber on. Within about 15 minutes the Sandalwood odour was no longer noticeable. On the following day I repeated the test but this time didn't turn the odour absorber on – after 20 minutes the Sandalwood odour was still noticeable. Whenever cooking foods such as fish that tend to emit odours I turn the odour absorber on before I begin cooking – the odours seem to dissipate more quickly than when the odour absorber is not turned on.


While any air cleaner isn't the ultimate solution to allergies and odours, it can be part of your clean air home protocol. You will, of course, still need to be proactive with dusting in your home, ensure adequate room ventilation, and control or eliminate, as much as possible, sources of allergens and odours.

What I like about the DualMax is that it's whisper quiet (at the lowest speed setting), the odour absorber can be switched off, there are no consumables to purchase, and cleaning the Truman Cell is relatively easy.

There are a few things I would have liked to see on the DualMax. It lacks a timer, which would enable me to schedule the length of time the air cleaner operates while I'm away from the house. There is no air quality sensor which would automatically measure the quality of the air in the room and then adjust the air cleaner's settings to increase the fan speed to clean the air as needed, and then revert the fan speed to it's lowest setting. Similarly, there is no sensor for odours, which means you have to leave the odour absorber on all the time, or remember to switch it on when you notice odours in the room.

Still, I'm quite pleased with the overall performance of the DualMax. From what I observed with cleaning the unit, it is removing fine particulate matter from the air, and my olfactory senses appreciate it. I'm not worried about the ozone emissions, as they're quite low, and I only use the odour absorber intermittently. 

If you have suffer from allergies or asthma, and the attendant symptoms they produce, then maybe you should give the DualMax a try.


  • Size: 11-3/4" W, 9-1/2" D, 18" H
  • Weight: 15-3/4 pounds
  • Coverage: Up to 900 sq. ft.
  • Power Consumption: 55 watts
  • CADR rate: 130 cubic feet per minute (at high setting) based on 1600 cu ft.
  • Air Filter Micron Rating: 0.01 micron
  • Ozone Emission: Less than 50 ppm
  • Controls:3 speed selection, on/off, and night light
  • Noise Levels: 18dB (low speed), 28dB (med speed), 45dB (high speed) at 6' from unit
  • Filters: Pre-filter, Truman Cell Filter
  • Helios Shield Odour Absorber
  • Remote control
  • Dual fans
  • Reusable, washable filters
  • Energy Star Certified
  • Includes: Remote control, dusting brush, user's guide
  • Warranty: 5 years

COMPANY:Oreck Canada
SOURCE:Oreck Canada Online
Carl Duguay
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