The Lock-Top model shown here has a stainless-steel cap mounted to diagonal spring wire. The cap stays level as it opens and closes.
The other style has a spring-loaded pivoting cast-metal damper hinged to the frame. It’s a lower profile and isn’t as noticeable from the ground when opened. The frame, cable, and retaining bracket mount the same as with the Lock-Top model.
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| Pop-Up Damper (Lock-Top model) | Hinged Damper |
I’ve used both styles of damper and have no preference. Both install and operate similarly. Prices for both models run from $150 to $350, depending on flue size. If the cable breaks on either type, the damper automatically opens. Eventually, the stainless-steel cables have to be replaced. Depending on use, this could be a couple of years or decades. I save the cable offcut when the damper is installed; plenty is left to replace cables for the fireplace of a single-story home. You also can buy cable at many hardware or boating supply stores.
| Sources All Season Control Cover www.controlcover.com/index.html Energy Top Damper & Seal Tight Damper www.usfireplaceproducts.com/products.htm RMR Top Damper and Chim-a-lator www.rumford.com/store/dampers.html |
| Read the complete article… Installing a Flue-Top Damper A rooftop model keeps rain outside and conditioned air inside by Mike Guertin  |
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