If you mean its new as in NEW get back to the supplier and ask why.
If its newly 'Secondhand' then check the floor and all wall vents previous owner may have sealed off some of vents which is dangerous apart from reducing air circulation. Try setting the window/s to first notch [night time venting when occupied] I get condensation in mine if I forget to set at least one window to vent over night.
bob
September 2009