Invisible Enemies and the Machine: Inside the IQAir GC MultiGas War Room

Written By: Dr Fahad Yasin


The IQAir MultiGas is a high-performance air purifier that utilizes cartridge-based chemisorption equivalent to 100 gas masks, 12 lbs of activated carbon, and a HyperHEPA filtration system. It has a large area coverage of 1,125 sq. ft. Its built-in screen and remote give you access to 6 fan speeds, programmable operation modes, and the lifespan of each filter. Our tests confirmed exceptional performance with a PM2.5 reduction to 0.1 and PM10 to 0.2.


  • Ideal for removing odors like tobacco smoke, pet smells, or musty odors
  • Exceptional air cleaning performance with PM2.5 reduced to 0.1, PM10 to .2, and AQI to 1 in one hour.
  • Large coverage area with the GC MultiGas suitable for rooms up to 1,125 sq. ft.


  • Large size and weight make it not great to place on counters or tables
  • No auto or sleep mode; the closest feature to these are programmable hours of operation.


Large room coverage and powerful odor-fighting
Design - 100%
Performance - 100%
Quality - 100%
Usability - 97%
Value - 94%


The IQAir GC MultiGas is a 44 lb, heavy-duty air purifier with excellent performance. Its distinguishing feature is the gas cartridges used in combination with activated carbon and a HEPA pre-filter. Designed for tackling strong odors and lingering smells, it scored among the highest we’ve seen in our performance tests. It was able to reduce PM2.5 to 0.1, PM10 to 0.2, and AQI to 1 in just 1 hour. It’s not the cheapest air purifier, but it is highly effective.

In This Review

Purification Testing Performance

– The GC MultiGas considerably reduced airborne particulates in testing.

– PM2.5 reduced from a baseline of 21.1 to 0.1 after 1 hour.

– PM10 reduced from a baseline of 37.3 to 0.2 after 1 hour.

– Particles reduced from 1,779 to just 10 in 1 hour.

– AQI reduced from 70 to 1 in 1 hour.

To determine the performance of the IQAir GC MultiGas we compare the difference between the starting baseline and the post-run data.

Starting Baseline

PM2.5: 21.1

PM10: 37.3

Particles: 1779

AQI: 70

After 1 hour

PM2.5: 0.1

PM10: 0.2

Particles: 10

AQI: 1

Avg – All Purifiers

PM2.5: 0.47

PM10: 0.70


AQI: 1.76

In general, we are wanting to see the four above measurements reach as close to 0 as possible. These readings are among those we’ve seen.
On average, based on all air purifiers tested to date, we see a PM2.5 of 0.47 and a PM10 of 0.70. Therefore, the GC MultiGas was significantly more effective at reducing airborne particulates than many purifiers we’ve tested.

Again, compared to the average performance, the GC MultiGas is significantly better than the average.

We use a professional air quality detector, the Temtop LKC-1000S+, to take a baseline measurement of the current air quality.
Below, we’ve included information on the testing criteria and what defines good vs. bad air quality.

The Filters

  • The purifier has a HyperHEPA pre-filter and GC MultiGas Cartridges
  • The pre-filter captures coarse, fine, and ultra-fine dust and hair particles.
  • The 4 GC MultiGas Cartridges are designed to control a wide range of chemicals and odors.

Noise Test

To measure the noise levels of the IQAir GC MultiGas, we use a sound meter app. We set the air purifier up, run it on each power setting, and measure the generated noise from about 3’ away.

Our results showed the following decibel levels from each mode.

Ambient Room

39.1 dB

Lowest Setting

40.1 dB

Highest Setting

67.7 dB

Common noise levels:

  • 20 dB – rustling leaves
  • 30 dB – whisper
  • 40 dB – quiet library, babbling brook
  • 50 dB – refrigerator, moderate rainfall
  • 60 dB – normal conversation, dishwashers
  • 70 dB – traffic, showers
  • 80 dB – alarm clock, telephone dial tone

Usability Tests

  • The purifier is large but comes with wheels for easy movement.
  • Setting it up is straightforward, with clear instructions provided.
  • On-board controls and a display screen facilitate easy operation. There’s also a remote control for convenience.
  • reasonable given its features and performance.


The setup takes a few steps, but they are straightforward.

Here’s what comes in the box:

  • GC MultiGas
  • Pre-filter (pre-installed)
  • Gas filters (x4) (in separate packaging)
  • Sleeves (x4) (in separate packaging)
  • Wheel mounting brackets (2x)
  • Wheels (4x)
  • Remote (batteries included)
  • Power cord
  • Manuals
  • Certification letter

Note – These cartridges contain 12 pounds of carbon. It can fall out when installing the sleeves, so be aware and careful during installation.

Controls & App

The IQAir GC MultiGas does not have app connectivity. Instead, it features a built-in console and a comprehensive display screen. 

There are four buttons to control the display screen that include:

  • Power On and standby
  • Up Arrow
  • Menu
  • Enter

These menus give you access to:

  • Power
  • Day of the week programming
  • Filter life shown in hours
  • Set fan speed while timer is on
  • Current speed and airflow in cfm
  • Adjust day & time
  • Adjust the CFMs
  • Change displayed language
  • Check model


  •  The purifier requires periodic replacement of the HyperHEPA pre-filter, the GC MultiGas cartridges, and the sleeves that go around the cartridges.
  •  The display screen shows the approximate percentage of filter life left in hours.
IQ Air GC MultiGas Gas and Sleeve

Size & Dimensions

As for size, the IQAir GC MultiGas is larger than your standard air purifier. It also covers a much larger area. IQ claims it can cover an area of 1,125 sq. ft. with a CADR of 300 CFM. This should be sufficient to cover any room in most homes, if not the entire home.

Here are the exact dimensions of the IQAir GC MultiGas:

  • Length – 16″
  • Width – 15”
  • Height – 28”
  • Weight – 44 lbs.

The height here includes the wheels, which are optional to install upon set-up. Due to the 44 lbs and overall size of the air purifier, I would highly recommend installing them to make it easier to maneuver.

IQAir MultiGas vs. HealthPro vs. HealthPro HealthPro Plus

GC MultiGas is compared to HealthPro and HealthPro Plus models. They have similar dimensions but differ in weight and the type of filters used. 

GC MultiGas HealthPro HealthPro Plus
Width15" 15" 15"
Length16" 16" 16"
Height28" 28" 24"
Weight44 lbs. 29 lbs. 35 lbs.
FiltersHEPA , Gas Cartridges, CarbonHEPAHEPA, Carbon
Coverage Area1125 sq. ft.
1240 sq. ft. 1125 sq. ft.
CADR300 CFM 330 CFM 330 CFM
Wifi Compatible No No No
Upgradable FilterNoIncludeIncluded
PriceCheck PriceCheck PriceCheck Price
The standard Healthpro has some slight spec advantages in coverage area and CADR. However, it is limited by its filters in what it can clean.
IQAir GC MutliGas
IQAir HealthPro
IQAir HealthPro Plus

IQAir GC MultiGas Specifications

ModelGC MultiGas
Weight44 lbs.
FiltersCarbon, HyperHEPA,
Wi-Fi Compatible No
Room Coverage1125 sq. ft.
CADR 300 cfm
ReturnsVaries by retailer.
Warranty10 years
PriceCheck Price

Should you buy the IQAir GC MultiGas?

The IQAir GC MultiGas offers robust air purification capabilities, especially for those dealing with gases, odors, or chemicals. If its features align with your needs and you’re willing to invest in a premium product, it could be a good fit. As with any purchase, it’s also wise to read user reviews, consult with the retailer about your specific needs, and possibly compare it with other models in the same category.

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