Only some firebox comes as a generous opening. A great many come compact — a cottage firebox measuring a fraction of what you'd expect. propane fireplace inserts Small gas fireplace inserts exist entirely because of these openings. The 36 size sits near a common sweet spot: substantial without being too big for the space.As a trusted provider of compact inserts, we help make finding the right size clear and easy. This guide highlights small gas fireplace inserts.Sizing for a Small HearthFireplace inserts for small fireplaces carry an absolute limit: they must physically fit. Take all four dimensions well ahead of choosing anything — masonry openings narrow at the back, and that trips up many. That size works in a large share of older openings.Not sure of the size? A good specialist will guide you to size it properly.Find a Compact InsertLooking to shop for a 36 gas fireplace insert? Whether you need a specific size or a general fit, a good selection make it easy to find the perfect fit.Get in touch with our fireplace specialists to learn more for help with your upgrade.