Greenhouse lighting side-effects: Community reaction

Abstract

With the help of a questionnaire, subjective reactions to the emitted light of greenhouses were determined for about 400 respondents divided among 10 different residential areas. The amount of vertically directed greenhouse light (vertical illuminance) at the observer points ranged between 0.003 and 2 Ix. The luminance above the greenhouse(s) caused by the upward light scattered in the atmosphere varied between 0.09 and 0.67 cd m^-2. The results showed that the annoyance caused by (a) the illumination of the dwelling, and (b) the direct view of the lighted greenhouses, was low; overall percentages 'a little' and 'highly annoyed' were about 10% and 3%, respectively. For these two aspects of annoyance, no significant dose-response relationships were obtained, although the (perceived) brightness of the illuminated dwelling significantly increased, and the brightness of the greenhouse itself tended to increase with vertical illuminance. The brightness of, and the annoyance caused by (c) the scattered light above the greenhouses significantly increased with luminance; overall, about 45% of the respondents rated the brightness of the glow as 'high', and 10% of them reported being 'highly annoyed.'