Can ventilation heat and cool
Ventilation is designed to improve air quality by filtration and introducing new air and flushing out old air. Many people are told it will heat in winter and cool in summer.
Well when it's dark and cold the roof will be the same so there will be no heat to push into the home. Through the day roof air will be warmer than out side and dryer so it can flush cold damp air out and replace it with dryer warmer filtered air.
This will give the home a dryer warmer feel. Its a bit like taking off wet clothes and putting on something dry.
If The sun has been out it will add some warmth but only while there is sun or for a limited time after. Remember regular dry warm air will lift the core temperature of your home. (17 degrees rather than 8 degrees in a damp home)
Tin roofs will get warm faster but concrete tile will hold it longer in most cases.
Cooling is impossible when your roof temperature is 45 to 50 degrees. in the evening when the roof temperature comes with in 5 degrees of the indoor temp of the home it can start moving air into the home creating air movement which will give the impression of cooling. normally from midnight you will be able to cool the home in summer.
Remember All ways change your filters on time .