Sources of emissions
Material inputs
1. DUSP uses four HP LaserJet 8100 printers. One is heavily used, requiring around 24 toner changes per year, equivalent to 480,000 pages of printing (20,000 pages per toner cart). The others are less heavily used, at 100,000 pages per printer per year. Two plotters are estimated to use 12 rolls per year between them, approximately equivalent to 12 reams of paperMaterial inputs to DUSP include all purchases of food, other consumables, equipment, furniture, and long term items such as office fitouts and the buildings themselves. For this limited first attempt at an audit, the only material input considered is paper for printing, which is responsible for 11.6 MTCDE.
Gathering data on all other inputs into DUSP is a major task and would be a logical extension of this project, maybe as part of a Material Flow Analysis.2. 45 jobs were carried out using the DUSP account at Copytech in April 2007, mostly black and white on letter size paper. 11 x 17 in print jobs were assumed to be equivalent to two pages of letter. The total count of page equivalents used in April was 10,267, giving an annual consumption of 123,204 pages from account jobs. No data on course readers was available so an estimate is used: 15 readers x 20 purchased x 300 pages = 90,000 additional sheets per year. Total Copytech printing 213,204 pages.
Methodology for paper consumption calculations
Paper used within DUSP comes from three streams - recycled paper in DUSP's own printers maintained by the CRN, and conventional paper in IS&T printers used by DUSP and printers/copiers Copytech. Paper consumption for non-Copytech printers was gathered by looking at the print cart replacement logs kept with each printer 1. For Copytech, details of all printing carried out for the last month was provided by Copytech staff. All pages were converted into equivalents of a single page of letter2.
3. Comparison charts in Chapter 3 of Paper Task Force Recommendations for Purchasing and Using Environmentally Preferable Paper, Environmental Defense Fund, 1995To calculate emissions from paper production, the complete lifecycle from production to disposal is considered, using paper industry data 3. To make and dispose of a ream of 100% recycled paper, 3.69 kg of greenhouse gases are emitted. For conventional non-recycled paper, 5.86 kg of greenhouse gases are emitted4
4. These data include disposal emissions, which are also counted in the section on waste. MIT's recycling stream is not classified by type so it is not possible to separate out paper from the overall amount. As a result, there is a small amount of double counting taking place.
| CRN printers | IST printers | Copytech | |
|---|---|---|---|
| Paper type | 100% recycled | Conventional | Conventional |
| Letter pages equivalent per year | 300,000 | 586,000 | 213,000 |
| Reams of letter equivalent per year | 600 | 1,172 | 426 |
| Emission factor (kg GHG per ream) | 3.69 | 5.86 | 5.86 |
| Total emissions (MTCDE) | 2.2 | 6.9 | 2.5 |
Limitations
No accounting is made for faculty and staff printers - these are provided individually and are probalby resource intensive due to poor economies of scale.
No accounting is made for photocopying on the department's own photocopies in headquarters or the CDD office.
The data for total pages in readers is an estimate. Further liaison with CopyTech is required to obtain accurate numbers for the total number of readers purchased and their total page count.
Toner and other printer supplies produce emissions. Given that we know the total page count per annum and the models of printers used, it should be possible to extent the scope of this section to include printer parts and consumables other than paper.
Although campus catering is shared by all MIT users and is not under the control of DUSP, some outlets such as the steam cafe have heavy use by DUSP members and therefore are entitled to providing input to the way it operates, including use of energy. The next stage of this audit should include campus food outlets.
Some catering is entirely within DUSP's control, including food at lunchtime seminars, student events, orientation, open house etc. The next stage of this audit should consider emissions from food purchased for DUSP events.
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