Tag Archives: top-mount damper

Fireplace Dampers – Throat Dampers vs Top-Mount Dampers

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An open damper is like an open windowFireplace dampers are an important component of your fireplace system and are often overlooked. Dampers serve the critical purpose of closing off the chimney when the fireplace is not in use. It’s an energy efficiency device, saving you money by preventing the loss of heat during the winter and preventing the loss of air conditioning during the summer. An open or missing damper is like an open window.

What is a Fireplace Damper?

In simple terms, a damper is a metal plate that closes the chimney flue. Homeowners often get the terms “damper” and “flue” mixed up. They’re very different but they work together. Simply stated, the damper is a metal plate; the flue is the pipe.

What is a Throat Damper?

Dampers come in different types and styles. Most dampers that are part of the original construction are called “throat dampers” because they’re located in the throat of the fireplace, above the firebox (where you make the fire) and below the smoke chamber and flue pipe. Throat dampers come in various styles–pivot hatchets, poker, rotary, spiral, vestal, Allied/Donley, and Majestic.

Examples of Throat Dampers        Photo credit: Chimney Safety Institute of America

Different regions of the country have different kinds of dampers. Another interesting point is that many dampers on the East Coast are removable and replaceable. This makes it much easier for chimney sweeps to be able to do a thorough cleaning of the system, especially into the smoke shelf behind the damper, because they don’t have to fight around the damper plate.

Here in San Diego and most of the West Coast, dampers are not removable and replaceable. That means that once the damper is damaged beyond repair, the damper cannot be replaced in the throat of the chimney without tearing open the facade which would be cost-prohibitive. In that case, there’s another solution–a top-mount damper.

What is a Top-Mount Damper?

If a throat damper becomes damaged beyond repair and cannot be replaced, our industry has created a solution called a Top-Mount Damper, also known as a Top-Sealing Damper.

A bracket for a top sealing damper
The bracket that holds the chain on a top-mount damper

This damper is placed at the top of the chimney stack. Most of these types of dampers are operated by a cable that runs all the way down the flue pipe and into a bracket inside the firebox. To close the damper, you simply pull the chain down and lock it in the bracket. To open the damper, you unhook the cable from the bracket and it pops open at the top because it’s spring-activated.

Top-mount dampers come in different styles. Some of the top-mount dampers are referred to as “Ice breakers,” to be used in colder regions.

Heat loss from a chimney without a damper
Without a damper
A chimney with a top sealing damper
With a top-mount damper

Four advantages to Top-Mount Dampers:

* Top-Mount Dampers seal better which will save you money on utility bills. When the cable is pulled down, the damper plate seals against a rubber, silicone or rope gasket which gives it a tight seal. Throat dampers, on the other hand, never provide a complete seal, especially as they get older and the damper plate warps. Without the seal, there are gaps that allow heat loss during the winter. Top-mount dampers will increase energy efficiency in your home and save you money in heating during the winter and air conditioning during the summer.

* For cold climate areas, the top-mount dampers keep the warm air inside the flue, helping the draft and reducing the likelihood of smoke coming into the room.

* If you don’t have a chimney cap, rodents and birds can come down the chimney and enter the house. The top-mount damper closes the chimney at the top, making it impossible for critters to get in.

* Here in San Diego and other parts of Southern California, we have a serious problem with aggressive Africanized Bees. Bees like to build their hives in chimneys. With a typical throat damper, the bees have free access to build their hive in the flue. A chimney cap isn’t enough to prevent the bees from entering the flue. With a top-mount damper, the flue is completely closed off at the top, making it almost impossible for bees to enter the flue.

One caveat…

Top-mount dampers can only be installed on masonry chimneys with open fireplaces. They cannot be installed in prefab fireplaces, free-standing stoves or Rampart General Pre-Cast systems due to the U.L. listing. The top-mount dampers also cannot be installed with windcaps.

In addition, top-mount dampers cannot be installed for a fireplace that has artificial gas logs or a log lighter because the damper must be locked fully open.

If you need your existing throat damper repaired or you’re in the market for a top-mount damper, contact a CSIA Certified Chimney Sweep.

An open fireplace damper is like an open window

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Money flying out of walletDuring these dog days of summer, many homeowners are making a very expensive mistake. Here in San Diego, homeowners are opening their SDG&E envelopes and getting sticker shock with astronomically high utility bills. What homeowners don’t realize is that by making a very simple change, they can save a great deal of money.

 

So here’s the tip: CLOSE YOUR FIREPLACE DAMPER!

What is a flue and what is a damper?

These terms are not interchangeable.

The flue is the vent pipe that allows gases, smoke, and heat to exhaust out of the home. The damper is a metal plate that opens and closes off the flue. When the fireplace is not in use, the damper should be closed in order to close off the flue.

Dampers are typically located at the bottom of the flue pipe, just above the firebox in the throat of the system.

Dampers typically have a rod or handle that you can push forward or backward. Other dampers move side to side, while others pull down or push up. It all depends on the type of fireplace you have.

In some cases, dampers can be located at the very top of the flue pipe with a chain that comes down and hooks in a bracket inside the firebox. These are called “top-mount” dampers. To close these dampers, you pull the chain down and hook it in the bracket. To open, you unhook the chain from the bracket and the damper plate pops open at the top because it’s spring activated.

Not all fireplaces have dampers but most do.

Why it’s important to close dampers

Here in San Diego, because our weather is typically very mild, many homeowners leave their dampers open all the time, not realizing that by doing so, their air conditioner is working overtime, costing the homeowner unnecessary money.

When the air conditioner is on and the damper is open, hot air from the outside is being drawn down the chimney and into the room. You’re actually sucking the hot air into your house. It totally defeats the whole purpose of using your air conditioner. In addition, if your chimney is dirty, you’re also sucking particulates of soot, which is a carcinogen, into the home. This is another reason to keep your chimney clean and your damper closed when the chimney is not in use.

It’s not just summertime that open dampers create problems. During winter time, when it’s cold outside, if your damper is open and you turn on your furnace, all you’re doing is sucking cold air into the home. This totally defeats the whole purpose of having your furnace turned on. So keep the damper closed during the winter time when you’re not using your fireplace.

How to tell if dampers are open

It’s not always easy to tell if your damper is open or closed. In fact, this is the #1 question when homeowners call me about their chimney. Unfortunately, because dampers open differently based on what type of system you have, I can’t give a conclusive answer over the phone. Here are several ways to tell if your throat damper is open or closed:

1) It’s actually easier to tell during the daytime than at night. One way you’re going to see more light from the sun than the other way. Keep in mind that because chimneys are not built straight up and down, you’ll rarely ever be able to see blue sky but one way you’ll be able to see more light than the other.

2) With a flashlight, look up from the firebox into the flue pipe. You should be able to see the metal damper plate in the throat of the system. When it’s open, you’ll actually feel more air movement than when it’s closed.

3) Light a match and blow it out. Immediately place the match close to the damper. The smoke from the blown-out match will indicate if the damper is open or closed.

4) Of course, there’s always the method that many homeowners use. Light the fire on a wing and a prayer. If it smokes out your house, then you know your damper is closed. We do not recommend this method due to the smoke damage to your home and to your lungs!

Here are examples of open and closed dampers.  This is looking from the firebox (where you make the fire) up the flue pipe:

Closed damper for masonry
Closed Damper for Masonry Chimney
Closed Damper for Pre-Fab Chimney
Open Damper for Masonry chimney
Open Damper for Masonry Chimney
Open Damper for Prefab Chimney

An Important Tip to Remember about Dampers

It’s not easy to remember, from season to season, which way the damper is open and which way is closed. To help me, I made a label and stuck it to the underside of the mantle which tells me which way to open. If I forget, I know where to look to find out easily.  Here’s the label I had on the underside of my own mantel:

Damper label

Not all dampers open this way so find out which way yours is open and make a label to place on the underside of your mantel.

Damper clamps

If your firebox is plumbed for gas, either for gas logs or a log lighter for burning with wood, then the damper has to be locked in a fully-open position with a clamp. You will not be able to close your damper. This is required by code in most areas of the United States. In this case, you may consider glass doors on the front of the fireplace.

Open window with curtainsRemember, an open damper is the same as an open window. Would you leave a window open when your air conditioning or furnace is on? Then why would you leave your fireplace damper open?