Question: I was looking at a wood stove insert which was burning at the store, the glass that was on the unit willy let the heat come through the window you i feel the hot radiant heat 5 feet away. My current heat exchanger does not let any heat out. Is this some new special kind of glass? Answer: Ceramic glass is used in most all wood stoves and inserts and has been for years. It is very effective at transferring radiant heat. But also keep in mind that the stove you saw also had features that made it PRODUCE more radiant heat. Some designs also push heat toward the front of the stove (glass) better than others. Therefore, replacing your glass with this expensive material may not boost your heat as much as you think.