Of course you could read the proper guide to fixing this problem
By just going and looking at the EU Code of Conduct Best Practice guide which explain all of this rather more comprehensively and deals with the other steps you should be taking.
http://re.jrc.ec.europa.eu/energyefficiency/html/standby_initiative_data_centers.htm
In the meantime stop buying high density IT equipment which creates local cooling problems until you have sorted out your airflow by containing either the hot or the cold air, yes, that practice is covered in the doc above too. High density does not mean high efficiency, it just means lots of empty spaces in racks which are out of power and cooling capacity.