The Education Minister has said teachers should open windows “at a lower level” if their classrooms are cold.
An online campaign by primary teachers highlighted classroom temperatures dropping below seven degrees in some classrooms this week due to ventilation requirements.
Health and safety rules require teaching to be suspended at 16 degrees.
Teachers’ unions have criticised a lack of progress on acquiring air filtration systems for classrooms.
Minister Norma Foley said going straight to technology, like Hepa filters, is not the answer.
She told Newstalk: "We are encouraged in terms of operating the windows to open them before class and after class, to exercise an abundance of practicality in terms of how you operate them during class. In other words, they can be opened at a lower level and I know myself, spending years within classrooms, that teachers and staff within school communities know exactly how to operate the opening and closing of windows."
Ms Foley added: "There is a use in some instances for Hepa filters, although again we're being well advised by Dr Mike Ryan of the World Health Organisation that going straight to technology is not the answer and that's the line that we would have taken within the Department. Where there are ventilation issues we have said throughout, since the reopening of schools, that if there are specific issues around ventilation it may be very different from one school to another; it may be the operation of vents or window replacement."