How do you prevent heat loss in a fireplace?

Author: Lawson Streich  |  Last update: Thursday, February 5, 2026

Check the seals around your fireplace flue damper—if the seals aren't tight, you could be losing home heating through the chimney. Insulate your chimney. Exhaust exiting through the chimney can create creosote build-up and can decrease the efficiency of your fireplace.

How to stop heat loss through a fireplace?

Cap off the unused chimney in a way that there can be no water incoming and no air movement. Air movement means heat loss. Close off the other open fireplace and install a wood burner. Close it off in a way the doesn't allow any heat to escape up the chimney.

Does putting a fan in front of a fireplace help?

This is a good question. Actually the answer is...it doesnt matter. The fan moves air within a room, not into it or from it. A fireplace needs as much air that is going up the chimney to be coming into the room where it is at. It is for that reason they are not efficient for heat.

How can I make my fireplace more heat efficient?

Improving the Efficiency of Your Fireplace
  1. Crack open a window nearest your fireplace. ...
  2. Turn on central or room fans to circulate heat. ...
  3. Use hard wood for fuel. ...
  4. Add a damper (if your fireplace does not have one) ...
  5. Use an inflatable flue plug. ...
  6. Install a top-sealing chimney damper. ...
  7. Bring outside air directly into the firebox.

How do I keep cold air from coming in my fireplace?

Another great way to block cold air is with a chimney balloon or plug. These devices are placed above the throat damper and inflated to completely block air from coming down into your fireplace. Balloons are designed to be used only when a fire isn't burning.

Stop Heat Loss Through Your Fireplace When It’s Not In Use, Save Energy

What can I put in front of my fireplace to keep cold air out?

'A chimney draft stopper is an efficient way to prevent cold air from entering your home through the fireplace opening.

Why does my fireplace make my house cold?

There's a firebox, where fires burn, and a chimney, up which go smoke and combustion gasses. The path for smoke also is a path for air. When a fireplace isn't in use, cold air from outside can come down the chimney into the home, and warm interior air can escape up through the flue.

How to get the most heat out of your fireplace?

Evenly distributing small pieces of wood throughout the fireplace will increase air circulation and speed up the burning of the wood. This creates a sustainable fire, but the wood burns faster. Placing large logs closer to the fireplace will keep the fire burning longer between refills, maximizing heat output per log.

Should I crack a window when using a fireplace?

Open a window when using the fireplace to prevent the room from becoming smoky. The air coming in from the window will go up the chimney. Before making a fire, open the glass doors, pull aside the screen curtains, and place the kindling, newspaper and logs inside.

Does closing the damper make the fire hotter?

Use the Damper to Control Heat

Depending on how far open or shut you have the damper, your fire will be smaller and cooler (and burn for longer), or larger and hotter (and burn more quickly). The damper is usually located at the bottom of the stove.

How do you circulate warm air from a fireplace?

If you have a forced-air heating and cooling system, turn on the fan and just use it to circulate the air that is created by your fireplace. This works best in more open-concept spaces and smaller homes where heat loss to the vents won't be noticeable.

How do I get more air in my fireplace?

The handle to open and close the damper should be above the fireplace opening. To open it, slide it to the right. To create fires that produce more heat, open the damper as wide as possible when lighting a fire. A wide-open damper will increase the amount of air reaching the fire and improve combustion.

Does a blower help a fireplace?

To combat the inefficiencies of radiant heat and to lessen heat loss through venting, adding a blower or fan kit can significantly improve the overall efficiency of your fireplace. In fact, some blowers can improve gas fireplace efficiency by as much as 80%!

How do you heat proof a fireplace?

Essential Fireproofing Materials for Your Fireplace

When it comes to keeping your fireplace safe and functional, fire cement, fireplace plaster, heatproof screed, and mortar are essential materials to have on hand.

Why does my fireplace not put out much heat?

Poor Draft: Things like blockages, creosote, and debris buildup – or possibly even small critters – can create a weak draft within the chimney. These things trap smoke and suffocate the fire, so your fire is likely dying before it really starts to heat your home.

How to seal an unused chimney?

1. Remove the exposed portion above the roof, cap/seal it, install new roofing at the hole—most effective but most expensive. 2. Cap the top of the flue—easy and cheap, and stops air but still have a thermal bridge.

How to make your fireplace more heat efficient?

6 Tips to Make Your Fireplace Super-Efficient
  1. Burn Seasoned wood. Dry wood burns hotter and more efficiently than damp (unseasoned) wood. ...
  2. Chimney cleaning. ...
  3. Make sure your damper works correctly. ...
  4. Fix excess drafts inside your home. ...
  5. Convert an inefficient masonry fireplace.

Do fireplaces heat better with glass doors closed?

Keeping fireplace doors open results in a more lively fire but can lead to heat loss and safety concerns. Closing fireplace doors improves efficiency, enhances safety, and directs heat into the room. Oxygen is vital for a healthy fire, and closed doors draw air from outside to maintain an efficient burn.

How long can I have a fire in my fireplace?

If the glass is properly sealed and the fireplace is fully vented this fireplace should run continuously without incident. HOWEVER, if you want to err on the side of caution, it is much better to only leave your fireplace burning, no matter what type it is, for two to three hours at a time.

How do I stop my fireplace from losing heat?

Keep the fireplace damper closed unless you have a fire burning. It can be easy to forget to close it when the fire has burned out, but keeping the damper open can cause drafts and heat loss in the rest of the house. But be careful, it can also be easy to remember to open it when you start a fire.

Are firebacks worth it?

Firebacks can increase a wood-burning fireplace's efficiency from about 10% to 15%. While not directly comparable to stoves or inserts, cast iron firebacks enhance a fireplace's radiating heat, providing warmth and ambiance unique to open hearths.

What type of fireplace gives the most heat?

So the question is not so much which one emits more heat; it's which one prevents the loss of more heat. In this regard, the gas fireplace clearly comes out on top. However, we cannot deny the greater pleasure people get from the crackling sound and wonderful aromas of a wood fireplace.

How do I keep cold air from coming through my fireplace?

3 Easy Things to Try to Fix a Cold Air Problems
  1. Close the Damper.
  2. Close Glass Doors.
  3. Have a professional Install Fireplace Doors (Note: some units cannot have doors, consult your local Chimney Sweep or fireplace store.)

How can I make my fireplace warm in my house?

5 Tips to Getting More Warmth Out of Your Fireplace
  1. Do a damper check. If you think about it logically, the chimney allows airflow so that smoke can escape when you light a fire, but when not in use, you're letting the warm air from your home out. ...
  2. Caulk it. ...
  3. Keep heat in. ...
  4. Install a heat exchanger. ...
  5. Seal it.

Should the fireplace damper be open or closed?

When you aren't using your fireplace, it should be closed to prevent heated and cooled air in your home from escaping. A closed damper also stops cold drafts from coming down the chimney. When you are using your fireplace, it needs to be open so that smoke can vent outside.

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