Teachers say funding is pointless if they do not spend it on the right ventilation devices.
The Government is to provide up to €72 million in funding that can be used by schools and childcare services to improve ventilation as part of efforts to prevent the spread of Covid-19.
Money will also be allocated for works which include IT upgrades, furniture, flooring or air filters.
Michael Gillespie is General Secretary of the Teachers Union of Ireland - he says they need the right advice, and they need it quickly.
"Time is of the essence now because we're in the race against the Omicron [variant of Covid-19] and we know it's more transmissible. It's pointless [the funding] unless we get the right machines to do the right job. Mechanical ventilation may require some physical work to put them in, and so we'll have the duel benefit of getting fresh air in, and keeping the heat in."
Aodhán Ó Ríordáin, of the Labour Party, believes providing HEPA filters for schools would be much more successful if the Department rolled them out.
Mr Ó Ríordáin told Newstalk: "Schools run on very different budgets depending on where they are so what would be more beneficial would be if the Government was to proactively install these filter systems themselves, but they're not doing that. They're putting the onus on schools, and as a result I don't think this is going to be very successful."
