AU2009202479A1 - Office Equipment Emissions Filter - Google Patents

Description

Editorial Note for 2009202479 There are three unnumbered description pages.

AUSTRALIA Patents Act 1990 STANDARD SPECIFICATION OFFICE EQUIPMENT EMISSIONS FILTER Provisional patent Application Number 2007905902 The invention is described in the following statement.

OFFICE EQUIPMENT EMISSIONS FILTER This innovation relates to a means to locally remove pollutants generated by office equipment such as printers and copiers locally, via a filter located in the ceiling, behind a 5 600x600 diffuser. Modern office photocopiers, laser printers and other office equipment appliances (OEA's) emit a range of pollutants such as volatile organic compounds (VOC's) and ultra fine particles (UFP's) into the workspace that lower the indoor air quality (IAQ) and can 10 produce adverse effects on an occupant's health. Eliminating these pollutants local to the source is more efficient than treating the whole air volume of the office to extract pollutants. A local filtration device offers a more efficient means of improving the IAQ than exhausting pollutants as conditioned air is not exhausted in large quantities from the space. OEA's are generally a gathering place within offices, which is another reason to 15 concentrate the treatment of pollutants at source. Currently, the problems are addressed by either exhausting contaminated air from over the OEA to outside, by increasing the overall outdoor air flow rate to the office environment to dilute any pollutants or using appropriate filter media to treat the whole 20 office's ventilation system. This system differs from others by specifically targeting OEA's with their own local treatment system. This will reduce running costs and minimise the spread of pollutants from the OEA. The proposed emissions filter will be installed locally above central copying and printing 25 appliances thereby addressing pollution issues at source. Air is circulated through a multi stage filter arrangement within the unit, firstly through a pre-filter to remove larger contaminants, secondly through a high efficiency filter (HEPA) for fine particles, thirdly through a VOC specific filter to remove gaseous 30 organic hydrocarbons. The introduction of a desiccant material into the filter media is also being considered to reduce humidity levels within the office environment which in turn will reduce the formation of mould spores being formed. By locating the filter above the OEA, the engineered air discharge from the filter will 35 assist in the capture of emissions by enveloping the periphery of the appliance with purified air, thereby drawing polluted air into the unit before it can disperse into the office environment. Since the OEA's emit heat, the positioning of the filter directly overhead will eliminate any contaminants being transported by with the direction of heat emission. 40 Sketch 1 shows the typical arrangement of the filter with a 600x600 multicone diffuser face. Air is dawn into the filter unit through the centre cores by a variable speed fan (2). A pre filter located on the reverse side of the grille (1), removes large particle pollutants from the air, protects the fan and prolongs the life of the later filters. Behind the fan (2) a 45 concentric cylindrical filter assembly of firstly a High Efficiency Particulate Arrestance Filter (HEPA) (3) and a specific VOC filter (4) are located. In these filters, the primary pollutants of UFP's and VOC's are absorbed and removed from the air stream before returning into the occupied space through the discharge plenum (8) and the outer cores of the multicone diffuser. 50 Sketch 3 shows an alternative arrangement of the unit with a "draw through" method of air movement. The principle of operation is still the same, with the air first being cleaned by the pre filter (1), then passing through the HEPA filter (3) and the VOC filter (4) before being discharged through the grille. 55 The selection of the design air flow will be optimised to give an engineered air flow pattern from the grille to maximise unit efficiency. This is shown in sketch 2. This operation is assisted by virtue of the pollutants leaving the equipment being warm and rising to the ceiling, assisted by the flow from the diffuser. 60 The integration of a desiccant impregnated final filter (6) will combat problems associated with high humidity within office environments and the health issues of mould which can result. 65 The fundamental principle behind the operation of the unit is that it is located behind a standard 600x600 diffuser, which separates intake from discharge. Mounting the system within a single plenum box, behind a 600x600 diffuser enables ease of installation and integration into suspended ceiling layouts and aesthetically matches traditional air conditioning system configurations. 70 A number of control options are possible for the unit, such as, wireless link with the operation of the specific OEA, 24 hour operation and warning lights on the grille facia for filter expiry due to increased pressure drop or preset fan operating limits. 75 The selection of a multicone diffuser for the grille makes the filter match traditional office environments with a suspended ceiling grid. Utilising a removable core (5), all maintenance can be undertaken through the front of the unit which will make installations in solid suspended ceilings possible. 80 In summary, by not exhausting air with the contaminants, running costs can be significantly reduced. Treated air, whether cooled or heated, is retained within the office environment with pollutants removed. The filter arrangement can be relocated whenever the OEA is relocated unlike existing ducting arrangements. 85 90

Claims (3)

1. The Office Equipment Emissions Filter comprises a combination of three filter 5 elements (Carbon, HEPA, VOC) and are located behind a 600x600mm multi-cone diffuser for ease of installation and integration.

2. The Office Equipment Emissions Filter, as described in claim 1, can absorb, and therefore remove from the air, pollutants emitted from office equipment. 10

3. Office Equipment Emissions Filter, as described in claim 1, utilises a modified 600x600mm multi-cone diffuser, such that air is draw in through the inner cores and discharged through the outer cores. 15