he more air tight the space the better this machine will perform. I think its a good idea to have a Ozone Measuring Device, to determine if the levels of Ozone is safe before entering the space. There is a possibility that some plants, foams and rubbers may be vulnerable to the effects of Ozone. Pets should be removed from treated areas as well. Dust Mites are a result of Damp Conditions inside the home and Bed Bugs can be transported back to your home from Hotels. Subscribe to Building Science to stay updated on the findings of this experiment and many others. NOTE: This machine produces high levels of Ozone which can be hazardous to your health. @southalabamahomeinspection2434