Dictionary of Allergies .. Air Changes Per Hour (ACH)
Air Changes Per Hour (ACH),
The movement of a volume of air in a given period of time; if a house has one air change per hour, it means that the air in the house will be replaced in a one-hour period.
Γκέλης Ν.Δ. - Λεξικό Αλλεργίας - Εκδόσεις ΒΕΛΛΕΡOΦΟΝΤΗΣ - Κόρινθος 2013
Gelis Ν.D. - Dictionary of Allergies - VELLEROFONTIS Publications - Corinth 2013