Why plug the fireplace?

Do you have a wood-burning fireplace in your home? Have you ever wondered whether it could be the reason your living room is drafty?

In the 1880s home I grew up in, each room had a fireplace. And each fireplace was plugged up with old tablecloths to keep them from being drafty. In all those years, we never ever lit a fire in any of those fireplaces.

Where’s the fun in that? We like having a fire once in a while. We just don’t like a drafty living room in between.

Even if with glass doors for the firebox, a damper in the flue, and a cap on the chimney–as our home has–these may not close your flue completely when you are not burning a fire.

You are probably losing lots of expensive heated air right up your fireplace chimney all winter long–as we were.

If you get a free or reduced cost home energy assessment via theEnergizeNY program, this fireplace plug may be one of the first recommendations (and the one with the shortest payback!). It was a recommendation in our report.

I snapped some photos looking up our fireplace flue. In the first photo, you can see the throat damper is set partly open (on purpose). You can also see the spider webs. 

In the second photo, I closed the damper as tight as the old metal flap will go: there is still a space around the edges for heated air from the room to rise up the flue. Bummer!

The presence of spider webs shows that during the summer months there is a draft here that will pull flying insects into the flue. Spiders are smart. They spin their webs where the air is moving to bring dinner to the web.

Even if I replaced our 90-year-old flue throat damper, it would still just be a metal lid with a lot of cold air stacked on top of it.  Adding a top-sealing damper on the top of the chimney under the cap would help. These have a pull chain that would hangs down inside the flue into the firebox so they can opened or closed easily. We should make both those improvements.

But, in the meantime, I took the DIY approach to install a flue pillow (a.k.a. “chimney balloon,” “fireplace plug,” or “draft stopper”).  I bought the one manufactured by Enviro Energy International and sold by Battic Door. 

They are made of a durable plastic inflatable balloon, an inflation/deflation tube, and a handle to place and prop them in place.

Installing a flue pillow is an easy DIY job. It took me about 5 minutes, including opening the mail order box that it came in. It is easy to remove whenever we want a fire.

The third photo shows the inflated plug installed, hiding and sealing the flue throat damper completely.  The fourth photo shows the pole that holds it up and the tube that inflates or deflates the bladder that comprises the plug.  When I do install a top-sealing damper, this particular plug design will allow the pull chain to pass through it.

Here is a short video from Ron Hazelton on how to install a “fireplace plug” as he calls it. You can find several kinds fireplace plugs on Amazon (what can’t you find there).  

Some manufacturers suggest installing it above the lower damper. Mr Hazelton just pushes his up against the top of the firebox just below the lower damper. That is exactly what I did.

Tips:

•    The only real trick is measuring the size of the space you want to seal. Most chimney flues are rectangular. It can be a bit sooty to stick a ruler up there.  So wear some gloves. Put a bright walk lamp in the fireplace floor to shine up so you can read the ruler or tape measure and see the contours of the damper frame. Pillows/plugs/stoppers come as rectangular or oval and vary in price by size from about $40 (9"X9") to $90 (45"X15").
•    In many older fireplaces like ours, you may notice a little shelf facing the front of the hearth forming the throat on which the damper is hinged. That shelf serves to keep precipitation and creosote from falling down into the firebox. I pressed our plug up against the underside of the damper and shelf.
•    For some fireside reading about fireplaces, here is Charles Tomlinson’s classic Fires Improv’d (1858) and  J. Pickering Thomas’ classic An Open Fireplace (1886).