The influence of thermal curtains on energy utilization in glass greenhouses

Measured night-time heat-load reductions associated with the deployment of thermal curtains in three glass greenhouses were found to be 47·1%, 43·3% and 49·9% respectively. Net present value (NPV) economic analysis was applied to these figures using ranges of installation and fuel costs as input variables. The results indicate that thermal curtains can be a very profitable investment except in those cases where either the grower has access to an unusually inexpensive source of heat or faces extremely high installation costs.