I am installing system 2 air con in 2 weeks time in our 2 bedrooms. However, one of the rooms has a ventilation panel at the top, with slanted glass panels and another room has a bedroom door with airvents. Do we need to seal up these openings? Checked with our aircon supplier Gain City but they said it is not necessary as cold air sinks and it is good to have ventilation. However, some friends have advised that if hot air is allowed to get in, the air con has to work harder and it will use more electricity. Any advice would be appreciated. Thanks.
