Door Filter™ technology provides a simple, elegant and cost-effective solution.
Typical solutions are either ineffective and highly energy consuming or invasive and cost-prohibitive – for example, the installation of separate, suite-by-suite ventilation systems.
With Door Filter, we’ve selected a filter medium that strikes a balance between ensuring maximum air flow while capturing the majority of particulate that would otherwise flow into your home.
This is important as the provision of fresh air is a basic requirement in our homes while the presence of particulate in the air we breathe can trigger lung damage.
In particular, exposure to allergens from house dust mites can be a contributing factor in the development of asthma as well as a cause of its symptoms. Other allergens from pollen, molds, animal dander etc. can cause asthmatic symptoms.
The following graphic explains the relative size of these common household allergens in microns (um). The average human hair is 150 microns. Its size has been magnified in the legend to the right so that the much smaller particle types can be seen. For instance, bacteria, light dust and animal dander are between 1 – 5 microns, whereas dust, plant spores and mold are between 5 – 10 microns:
Average Human Hair
Lint, Particles Visible to the Naked Eye
Average Dust, Plant, Fertilizer, Pollen
Average Dust, Plant Spores, Mold
Bacteria, Light Dust, Animal Dander
Bacteria, Tobacco and Cooking Smoke, Metallic Fumes
Door Filter is designed to capture these types of allergens and a range of particulate types of similar size.
For instance, a soiled Door Filter was tested and lab results indicated the following types of particulate as shown in the table below. The right hand column shows the typical diameter of these types of particulate; namely: 0.6 – 6.34 microns.
|Particle Type Captured||Symbol||Size (microns, um)*||Relative Size of Particulate|
|Dolomite||Mg||6.34µm||Average Dust, Plant Spores, Mold|
|Calcite||Ca||4.64µm||Bacteria, Light Dust, Animal Dander|
|Quartz||Si||3.90µm||Bacteria, Light Dust, Animal Dander|
|Sodium Chloride||Na||3.78µm||Bacteria, Light Dust, Animal Dander|
|Rust (Iron Oxides)||Fe||3.42µm||Bacteria, Light Dust, Animal Dander|
|Organic / carbon||OC||0.6-1.9 um+||Bacteria, Tobacco and Cooking Smoke, Metallic Fumes|
* Aerodynamic mass median diameter (MMD) as established by Milford and Davidson (1985), Table II on page 1255
+ OC is mainly found in smaller particles as noted in paper by Offenberg and Baker (2000), Table 2 on page 1513
Corridor Ventilation Strategy
Millions of North Americans have made the choice to live in rental or condominium apartments buildings. Public policy makers encourage this as an excellent option for the environment as it supports effective land, energy and water use. Despite these benefits, there is a long list of common complaints among apartment dwellers related to indoor air quality. This is a result of the ineffective “Corridor Ventilation Strategy” which has been replicated since the 1960’s in thousands of buildings across North America (and internationally).
Essentially, fresh air is pumped into common corridors and then makes its way into each apartment unit through the spaces around a unit’s entry door (between the door and its frame).
While air enters into a unit, so may a host of other irritants like dust, odor, noise, pests, light, and cooking fumes. These system failings are well documented through academic research.
Typical solutions are either ineffective and highly energy consuming or invasive and cost-prohibitive – for example, the installation of separate, suite-by-suite suite ventilation systems.
By contrast, the Door Filter™ technology provides a simple, elegant and cost-effective solution that works with and enhances the existing corridor ventilation system. Door Filter™ is an innovative, new, North American-designed filtration product that improves the indoor air quality within apartment units as it reduces a variety of air pollutants while still allowing proper air movement from the corridor to the apartment unit. Door Filter™ is a dense ABS extension that is fitted and secured to the bottom of the inside face of an apartment entry door and lined with a door sweep (to seal off units). A removable multi-stage air filter (charcoal, particulate and microbe) is placed inside the device. Small openings in the ABS allow air to pass through the device and internal filter promoting clean airflow into the apartment unit. The system has the added benefit of decreasing noise and eliminating light transfer from the corridor into the suite. In short, with Door Filter™, you can now add fresh air to the many environmental benefits of apartment living.