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Upgrading your Existing Fireplace - Glass Doors, improved dampers, Firebacks and Heat Exchangers can help.

Ah, the Fireplace....that icon of luxury and relaxation that represents an escape from the pressures of everyday life. The flickering flames mesmerize and make one forget that most fireplaces add significantly to the cost of home heating! Yes, that big hole in the wall can be responsible for your having to work HARDER to pay your energy bills...and very few folks enjoy higher monthly bills.

Open fireplaces can vary greatly in their efficiency, typically being anywhere from -20% (meaning they lose a lot more heat than they gain) to as much as +10-20% positive.....which indicates that they deliver a small portion of the wood's heat back into your home.

You could certainly convert your fireplace with a fireplace inserted stove, but this can be an expensive proposition (approx. $3,000). Occasional fireplace users also may not want to change the look of their decor with such an installation. There are, however, some less expensive steps you can take to assure you are getting the most from your existing fireplace.


Having a good fireplace grate can increase the efficiency of a fireplace AND make fires easier to start and tend. Some grates are specially designed to make the wood fire radiate better into the room. An example is "The Grate Wall of Fire", which uses clever design to make the glowing part of the logs project heat forward. Note that this type of grate works best with open fires, when a glass door is either not installed or left open during the hottest parts of the fire.

An example of a high quality standard grate can be found in a product called The Self Feeding Fireplace Grate. These grates properly cradle the wood and allow for air to enter from underneath. The rounded design allow the wood to...

Fireplace Insert (Jotul)


If you enjoy using your fireplace but don’t like the associated energy costs, you might want to consider purchasing a fireplace insert. An insert is basically a wood stove designed to fit into a conventional open fireplace. Like wood stoves, new inserts must be EPA certified, making them clean burning and highly efficient.

Inserts are made from plate steel or cast iron and most have glass doors so you can see the flames. These appliances fit into the opening of the fireplace, with some models protruding onto the hearth. An insert which is extended out may be more efficient because the sides, top, and bottom provide additional radiant heat. Inserts often have blowers, which can significantly improve efficiency and the heat circulation. Blowers are usually mounted in the front or along the sides of the insert. Some blowers are controlled manually, while others are regulated by a thermostat.


In the past, most installers placed inserts in the fireplace without any chimney connections. This method, in some cases, allowed creosote to build up inside the fireplace, presenting a potential fire hazard. To prevent this, the National Fire Protection Association (NFPA) now requires that inserts be installed with at least (minimum) a positive connection to the chimney. Inserts must have a connector between the appliance outlet and the first section of the flue liner. This sends the smoke and gases up and out of the chimney more directly, minimizing combustible deposits that condense in the fireplace. Most fireplace insert installations will benefit from a full relining of the chimney, because the smaller pipe size will provide a better draft as well as an added margin of safety.

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Wood stoves are wood-burning appliances that sit on the floor of the room, usually away from the wall. Some of the newer models may now be placed as close as 8 inches from the wall. Because they must be certified by the EPA, most newer wood stoves are clean burning and have relatively high heating efficiencies that range from 63 to 80 percent.

Wood stoves are available in a variety of styles that vary from contemporary to traditional-looking models. They are usually cast iron, plate steel, sheet metal, soapstone/tile or a combination of these materials. Some manufacturers have altered the appearance of the traditional cast-iron stove by applying different materials to the outside of the stove. Stoves are frequently enameled in a variety of colors and some are covered with marble or stone. Steel-plate stoves are generally made of 3/16- to 1/4-inch thick plates cut and stamped to shape. Cast-iron stoves are made of cast parts bolted together. The parts should have detailed lines and clean surfaces free of grains. The characteristics of steel and cast iron are not significantly different, therefore you can make your choice based on size, budget and the design of the stove.

The following article compares common stove materials:


You can tell if a wood stove is well-made by checking for clean castings, smooth welds, tight doors, smoothly-operating draft controls, and the appearance of good workmanship. Most stoves also have firebricks or metal plates to prevent burnout. These materials increase both the life of the stove and, to some extent, the thermal mass (the heat’s storage medium). After the fire is out, a 500-pound stove radiates heat several hours longer than a 250-pound stove. Stoves may have doors on the top, on the side, or both.


Many of the new wood stoves...
Purchasing a fireplace can be one of the most beneficial additions that you can make for your home. As one of the top investments for remodeling, a fireplace can return as much as 130 percent of the initial cost when you sell your home. About 78 percent of prospective home buyers in the nation seek homes with fireplaces, and many looking for homes costing over $200,000 see the fireplace as the most appealing amenity.

But what about the Energy Equation? Luckily, many fireplaces of today can provide welcome heat from the wood. In fact, some newer units match the efficiency of the best woodstove and central heaters!

Fireplaces are a more traditional type of wood-burning appliance. In the past, most people chose to install a fireplace for the aesthetics and recreational enjoyment of the hearth, rather than for heating purposes. Of all the wood-burning appliances, fireplaces offer the largest view of the flames. With new contemporary designs, some are available with 2-, 3-, and 4-sided views.

Until recently, most fireplaces heated the home inefficiently. Some of them, such as most masonry (brick) fireplaces, are still this way. The flue of a masonry fireplace allows warm indoor air to escape up the chimney. Conventional masonry fireplaces can lose between 80 and 100 percent of their heat plus an additional 10 percent of the heat already in the room. They can actually remove more heat than they supply.

Factory-Built Fireplaces

New, energy-efficient, factory-built (sometimes called zero-clearance fireplaces) can often provide more heat than their traditional masonry counterparts. One of the most redeeming features of these fireplaces is that they require low clearance between themselves and other combustible surfaces. For example, they can be placed between 1/2 and 2 inches away from walls with wood studs without any danger of fire. Instead of a brick chimney, these fireplaces use a stainless steel lightweight metal flue. This means much lighter foundation...
Installing a Woodstove - The Basics on How to Install a Wood Burning Stove. .

The Chimney

* Insulated Metal Chimney

* Masonry Chimneys

* Installing into an Existing Fireplace or Chimney

The Stovepipe

* Single Wall Stovepipe

* Close Clearance Stovepipe

Floor and Wall Protection

* Underneath Your Stove

* On the Walls

Legal Disclaimer - This document is not designed to replace your owners manual. It is written to provide an overview of safe installation practice. Consult your hearth professional, building officials and owners manual for the specific installation needs of your appliance. Your dealer or local building official is the best source for additional information. You can also find a list of installers certified by The National Fireplace Institute:

(http://www.nficertified.org/pages_consumers/consumers-1.html), an educational foundation.

The Chimney

OK, we’re going to talk a little about how to properly install a wood burning stove. The first thing we have to do is to forget about the woodstove and concentrate on the most important part of an installation - the chimney!

RULE #1 - Every Wood stove Must Have a Chimney

This means either a sound masonry chimney (more on these later) or a UL approved Stainless Steel Class “A” Insulated Chimney. No - you cannot use stovepipe through the window or roof!

Double & Triple Wall Insulated Class “A” Chimneys

Now that we have that out of the way, let’s look at the most popular option for new installations, the Class “A” Insulated Chimney (now commonly called HT or High Temperature). The diagram above shows the three most common installation types.

Type #1 would be common in any single story construction. Regular black stove pipe is run upwards from the stove and connects with the Insulated Chimney at a special support box located immediately below the ceiling level. Insulated chimney is then stacked up until the required height is obtained. All...
Note: The fireplaces being discussed in this article are made of sheet metal and have metal round chimneys. These are known by various names such as:

1. Pre-fab or Prefabricated metal fireplaces.

2. Zero-Clearance or ZC or “0” clearance fireplaces.

3. “Builder Boxes” or similar terms which denote their popularity with home building contractors.

Common brand names - with (d) representing companies which are out of business, are Majestic, Superior/Lennox, Heatilator, FMI, Temco (d), Preway (d), Martin (d) and Marco (d).

In order to avoid confusion, we will use the term “prefab metal fireplace” or prefab fireplace” in this article to refer to these built in appliances.

Since their invention about 50 years ago, metal fireplaces have become commonplace in newly built homes - in fact, so much so that 100% masonry fireplaces now account for only a small fraction of the construction market. The ease with which they can be installed as well as the lower costs involved have made them a fixture in tens of millions of N. American homes. Many of these fireplaces have aged and are often in need of upgrading in these various ways:

1. Parts replacement of components such as interior linings and chimney caps.

2. Glass fireplace doors - either replacement or initial installation.

3. Energy Saving upgrades - prefabs often spill cold drafts into the home.

4. Heat exchangers, gas logs and other upgrades relating to burning and heat output

Is it really a Prefab?

The first order of business is to determine if your fireplace is prefab or masonry. You can identify which type of fireplace you have by looking up with a flashlight toward the damper area from inside the home - wear safety glasses to avoid dust and particles! A factory-built fireplace will have a round damper and a round pipe, usually 7-11” in internal diameter. The damper plate on a masonry fireplace is usually rectangular, and approx. 6” x 24”. You may also be able to ID your fireplace by looking at the...
isher Stoves were a brand that is credited for starting the modern Airtight and Efficient Woodstove boom.

Starting with an plan in Bob Fishers mind, the company expanded to franchisees all over the world and fueled the energy Independence craze during the 1970’s Oil shocks.

For the collector or history buff, there is a LOT to know about Fisher Stoves, and we at Hearth.com are trying hard to collect every possible scrap of information. Below is some of the most popular information along with links to our treasure trove of Fisher Knowledge….

Basic Fisher Stove Model Identification:

Bear Series (single door stoves)

Papa Bear ; Single door, two air intakes, takes up to 30 inch log. Heats up to 2250 sf.

Mama Bear ; Single door, two air intakes, takes up to 24 inch log. Heats up to 1750 sf.

Baby Bear ; Single door, single ait intake , takes up to 18 inch log. Heats up to 1250 sf.

Fireplace Series (double door stoves)

Grandma Bear ; takes up to 20 inch log and uses 5 bricks across back. Heats up to 1750.

Grandpa Bear ; takes up to 24 inch log and uses 6 bricks across back. Heats up to 2250.

Flat top doors were painted black, cast iron. They are pre 1980.

Arched top doors are after 1979. They were available black, nickel plate, brass plate, and later brass and glass.

All stoves made to go into a hearth or fireplace are called Fisher Fireplace Inserts. (no bear name given)

They were available with solid cast iron doors, or brass and glass doors for heating up to 2000 sf.

Later, a smaller Insert with brass and glass or solid cast iron doors called the Honey Bear Insert was made to heat up to 1200 sf. The Polar Bear Insert was for fabricated metal or “zero clearance” fireplaces.

The first Freestanding Pedestal type fireplace / stove was the Mobile Home approved Goldilocks (Logs to 16”) with outdoor air intake up through the center pedestal, no air intake through the doors. By 1983, two more pedstal type stoves were offered called Teddy Bear (same size as...
OK, you have decided to get a stove or an insert, and are needing a place to put it. You may already have an existing fireplace, or you may be creating an entirely new installation.

This article is intended to deal ONLY with the Hearth, or the floor surface that the stove or insert is sitting on. The walls around and behind the installation are a separate subject, and are discussed in this article and a second article as well as in many threads on our forums. This article is an effort to summarize these topics and come up with a list of general “best practice” recommendations on how to design a hearth that works well and promotes maximum safety.

As usual all the standard disclaimers apply - while we attempt to give the best advice possible, we can’t see your setup or tell what will work in every case. Your local code enforcement folks (AHJ) have the final word, and we advise consulting with them and other qualified building professionals about the details of your particular installation. Neither Hearth.com, nor any of the contributors to this article accept any responsibility or liability for the results of your installation, as you alone are responsible for the results of your work.

A Finished Hearth (details on this hearth)

The hearth structure is also sometimes referred to as a “Hearth Pad” or just “pad” for short, the terms will be used interchangeably throughout this article.

If one is installing on top of a concrete or other inherently non combustible floor, little in the way of a hearth pad is needed, other than possibly for aesthetic reasons. However most of us are going to be...
Installing a Wood Burning Fireplace Insert - Part #1

Please note: This article is intended as an overview of the installation - it is very important to obtain and use your owners manual for specific details which may apply to your fireplace insert model.

Open fireplaces generally produce very little heat - and also pull air which you already paid to heat up the flue. A wood burning fireplace insert can solve the problem of low efficiency, as well as provide longer burn times and greater safety…..BUT it must be planned and installed correctly.

As a first step, please become familiar with the definitions of a fireplace or hearth stove. A good article for the basics is located here.

Next, determine the type of fireplace which exists in your home. There are these basic types:

Masonry based fireplace - This includes the following sub-groups:

1. 100% masonry site-built fireplaces - these are usually constructed by a mason on-site using a combination of concrete block, brick, firebrick and clay flue tiles. Your masonry fireplace is probably lined with clay flue tile - an orange, red or yellow terra-cotta material. You can see these tiles, which are usually square or rectangular, from the top and/or bottom of the fireplace.

2. Heatform - or Metal fireplace with masonry chimney:


A Heatform is a metal firebox which is built into a full masonry chimney. These were very popular in the period from 1960-1980 as it eliminated the need for a trained mason to build sloping firebox walls.

3. 100% prefabricated masonry - Some MASONRY fireplaces are now built at a factory and hauled out to the job site to be set on a concrete foundation. Many of these also have special masonry chimneys made of pumice (volcanic rock). Brand names include Isokern and Firerock as well as many smaller local companies.

Metal Fireplace - also...
Obtaining Domestic Hot Water from a Wood or Coal Stove

Many folks have expressed a desire to obtain hot water from their stoves. First, I should mention that this article refers to Domestic Hot Water, meaning the water that is used to wash dishes, take showers, etc. A woodstove cannot produce the volumes of water needed to heat your home through a baseboard or radiator system. If you are looking to heat your entire home AND produce your Domestic Hot Water, take a look at some of the wood burning central heating systems. These produce your hot water AND heat your home!

There are two different types of heat exchangers which can be fitted to stoves and used to heat your domestic water.

1. External Heat exchangers - if the stove has a large flat surface on the rear, then a serpentine can be fabricated that goes against the rear. If it is enclosed with a layer of sheet metal behind this coil, it will provide better heat. I’ve had them custom made..but the same shops that make DHW coils (tankless heater) for hot water boilers. These coils were made from a finned copper (usually 3/4”), so much the better for heat exchange. You could make your own by using 180 degree copper bends, but use high-temp (silver) solder so the coils don’t come apart if they ever hit a very high temperature.This would only happen if they ran out of water and the stove was VERY hot. Input would be into the bottom of the coil, and output from the top. A pressure relief valve should be installed next to the coil…WITH NO VALVES BETWEEN THIS PRESSURE RELIEF VALVE AND THE COIL.

2. Internal Heat Exchangers - A few companies make such an item, although it may not be easy to find. The best ones are small tanks or coils made of stainless steel. The kits come with instructions and a pressure relief valve. In order to install an internal heat exchanger, a hole must be drilled into the stove body. This may be a job for a professional, as you don’t want to compromise the safety or integrity of your...