AIR PURIFIER

Abstract

An air purifier comprising a removable particulate or gas filter, an air flow generator, a means for controlling said air flow generator, a first air flow setting with an air filtration air flow speed and a second air flow setting which correlates with sterilisation of an internal surface of the air purifier and/or removable particulate or gas filter. A method for sterilising an internal surface of an air purifier according to any preceding claim by generating an air flow correlating with said second air flow setting. A method for sterilising an internal surface of an air purifier according to any preceding claim by generating an air flow correlating with said second air flow setting. A method for sterilising a removable filter in an air purifier according to any preceding claim by generating an air flow correlating with said second air flow setting. A method for preventing microbial growth on an internal surface of or a removable filter rom an air purifier by activating the air flow generator.

Claims

1. An air purifier comprising a removable particulate or gas filter, an air flow generator, a means for controlling said air flow generator, a first air flow setting with an air filtration air flow speed and a second air flow setting which correlates with sterilisation of an internal surface of the air purifier and/or removable particulate or gas filter and wherein the air flow speed measured at the removable filter at the second air flow setting is from 0.1 to 1.2 cms.sup.−1.

2. The air purifier according to claim 1 wherein the air flow speed measured at the removable filter at the first setting is at least 1.5 cms.sup.−1.

3. The air purifier according to claim 1 wherein the air flow speed measured at the removable filter at the second setting is from 1 to 40% the air flow speed generated at the first setting.

4. The air purifier according to claim 1 wherein the air flow speed measured at the removable filter at the second setting is from 1 to 10% the air flow speed generated at the first setting.

5. The air purifier according to claim 1 comprising a timer for timing the period since last air filtration event.

6. The air purifier according to claim 1 comprising a means for actuating said second air flow setting.

7. A method for sterilising an internal surface of an air purifier according to claim 1 wherein sterilizing is achieved by generating an air flow correlating with said second air flow setting.

8. The method for sterilising a removable filter in an air purifier according to claim 7 wherein sterilizing is achieved by generating an air flow correlating with said second air flow setting.

9. The method for preventing microbial growth on an internal surface of a removable filter from an air purifier according to claim 7 by activating the air flow generator.

10. The method according to claim 9 wherein said air flow generator is activated after a predetermined period of time since last activation of said air flow generator.

Description

EXAMPLE 1

[0041] The following experiment sets out to assess the impact of a low air draft alone on micro-organism viability on a substrate, in this case a particulate filter. No ionisation of the substrate took place.

[0042] The micro-organisms used were Staphylococcus aureus and Pseudomonas aeruginosa and the incubation period to generate the biofilm was 5 days.

[0043] Results:

TABLE-US-00001 Airflow rate (ms.sup.−1) 0.018 0.4 1 Log reduction microbes −0.75 0.52 1.2

[0044] A low air draft of 0.018 ms.sup.−1 resulted in no reduction of micro-organism growth though this still resulted in some slowing down of growth.

EXAMPLE 2

[0045] An air purifier was set up such that a particulate filter was subjected to ionisation as well as a low air draft (1 cms.sup.−1). The air draft was for 10 hours and the ionisation for 2 hours with the ionisation step coming first.

[0046] Again, the ioniser was set at −5 kV and the test micro-organism (Staphylococcus aureus and Pseudomonas aeruginosa) was allowed to grow for 5 days prior to the test.

[0047] The control showed log micro-organism count of 6 while the test score was 2.5.

EXAMPLE 3

[0048] An air purifier was set up such that an interior surface of the purifier was subjected to ionisation as well as a low air draft (1 cms.sup.−1). The air draft was for 10 hours and the ionisation for 2 hours with the ionisation step coming first.

[0049] Again, the ioniser was set at −5 kV and the test micro-organism (Staphylococcus aureus and Pseudomonas aeruginosa) was allowed to grow for 5 days prior to the test.

[0050] The control showed 152 colonies of micro-organism while the test score showed 6.