Lessons Learned from Labyrinth Type of Air Preconditioning in Exergy-Aware Solar Greenhouses
An exergy-based model hypothesizes that labyrinth-type ground-to-air heat exchangers are responsible for carbon dioxide emissions if the exergy of power demand concerning ancillaries like fans and pumps exceeds the thermal exergy gain. This hypothesis was analyzed for a novel solar greenhouse proposal in northern Holland, primarily using heat pipes. Minimum electrical power demand without any need for fossil fuels were the main findings on a holistic basis. New definitions, namely nearly-zero-exergy greenhouse and nearly-zero carbon greenhouse, were developed with new metrics to quantify the hypothesis. Results show that the exergy approach provides crucial insight for the design of labyrinth-type ground-to-air heat exchangers and sets new constraints about limited environmental benefits.