In many shops, the doors are left open even in summer season during air conditioning. Cold air flows out through doorway openings. The loss of cool air is a serious problem for energy conservation. To reduce the air flow rate, a shop curtain, noren, was installed and the effect was quantified by measuring velocity and temperature distributions. By installing a shop curtain, the air flow rate was reduced by 20 – 85 %. A simple calculation formula for gravitational ventilation was modified to account for opening ratio of shop curtain. The calculation results agreed well with measurements.
OHARA et al. (Sun,) studied this question.