Does the Monessen vent less 60 inch require the glass to be installed or can it remain off with no glass?

Yes, this fireplace requires the glass to be installed. This model has a piece of air deflection glass that is required to keep the flames from being pushed toward the back of the unit. It also requires crushed glass in the bottom which will help with quick and complete ignition across the burner.

If you have any further questions, please call us and we will be happy to assist you.