Martin, D.P. and Ringwood, John and Grant, J.J.
(2002)
A Single-bladed Ventilation Damper: Mixing Ratio Models and Measurement.
Biosystems Engineering, 82 (2).
pp. 187-198.
ISSN 1537-5110
Abstract
Fresh air control in a mushroom tunnel is by adjustment of the ventilation damper in the air handling unit,
and this has a major impact on the climate of the tunnel. Damper angle affects the proportion of fresh to
recirculated air, i.e. the mixing ratio. The primary objective of this study was to determine the mixing ratio as a
function of the damper angle, thus facilitating predictive climate control strategies. Measurement of mixing
ratio was achieved by psychrometric measurement of the fresh, recirculated and mixed airflows. A full range of
damper angles, from horizontal to vertical, i.e. 0–908, at 98 intervals were used. Compared to mixing ratio
models from the literature, results showed that the effect of damper angle on mixing ratio can be better
modelled by an exponential relation, but a much better model is a sigmoid. The benefit obtained for an
exponential model was a fit improvement of 37%, but a sigmoid model gave a 583% fit improvement. In
practice, model parameterization could be by low-cost automatic calibration during periods when the tunnel is
unoccupied, subject to the constraint that a minimum psychrometric distance between the fresh and
recirculated airflows is maintained during data collection.
| Item Type: |
Article
|
| Keywords: |
Single-bladed Ventilation Damper; Mixing Ratio Models; Measurement; |
| Academic Unit: |
Faculty of Science and Engineering > Experimental Physics |
| Item ID: |
6914 |
| Identification Number: |
https://doi.org/10.1006/bioe.2002.0063 |
| Depositing User: |
Professor John Ringwood
|
| Date Deposited: |
21 Jan 2016 15:02 |
| Journal or Publication Title: |
Biosystems Engineering |
| Publisher: |
Elsevier |
| Refereed: |
Yes |
| URI: |
|
| Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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