Drolet Escape 1400i is an Ul and EPA certified stove. If this is the model you are looking for. Almost all installed in exterior exposed fireplaces /chimneys require a full stainless stell UL 1777 aproved liner systems. The problem with mail order or Northern tools is installation they do not schedule it. Aufull hard to get warranty issues solved with a 3oo lb beast to move and ship All these factors have to be considered not just price. the Drolet is what it, is a lower cost plate steel insert, that will provide. suplemental heating In a month the big box stores will have simmilar stoves called Englanders plus sell venting material For more detailed responses you should post on Hearth.com and detail your existing fireplace flue size and setup there you will get advice from a lot of experienced users dealers