Cite? What their site sez is “The area around a fireplace is actually colder than the rest of the room when a fire is burning.
Fireplaces are notoriously inefficient for heating - as noted above they send most of the heat up the chimney and the vacuum this creates draws cold outside air into the room.
A long time ago I lived in an old New England farmhouse built around the time of the revolutionary war. It had a “colonial style” fireplace in nearly every ground-floor room, like the one shown here. Notice how the brick hearth is extended well out into the room. This puzzled me until someone explained that the fire was actually built out on the extended hearth. This way, the draft from the chimney would still draw the smoke out, but heat from the fire would radiate out into the room better than if it was built directly under the chimney. Note, for some reason the fire in the picture I linked is not located this way, perhaps for safety reasons.
SS
If you have a fireplace with no damper you are losing heat through it whether a fire is burning or not. If you have a damper you can control the draft to minimize heat loss. If your fireplace and chimney are in the center of the house, more of the heat produced by your fire will be radiated into the house. The greater the thermal mass of the hearth system and the house, the more heat will be kept in the house. Doors and or damper control will allow a well designed fireplace to produce more net heat than it takes out of the house. Otherwise a house with a fire in the fireplace would eventually reach the outside temperature without an additional heat source.
Actually, before the invention of the chimney in the middle ages (in response to the Little Ice Age), houses had an open fire in the middle of the room, with an opening in the roof to let the smoke out. The open space had to be fairly large, and the hole, too. Once the circulation pattern was set up, the smoke would rise up and out fairly cleanly (relatively speaking).
If you watched the scenes of the King’s palace in Rohan in LOTR, you can see this type of a setup in use.
Ben Franklin invented the Franklin stove to counter this problem. Has a more efficient draft.
But that is just a quiz, not a actual Mythbusters experiment.
Look, if fireplaces made house colder, everyone pre - 1700’s would have frozen to death in the winter. Thus, it’s clearly not so. Not to mention our mountain cabin was heated by nothing other than a fireplace, and it was warm (as long as we fed the fire) even when there was several feet of snow outside.
What I think they are trying to say- and doing a very poor job of it- is that a fireplace keep the room you are in warm. But in a modern house, the fireplace draws air in from other rooms of the house, which often then draw cold air from outside. Which cold air is then heated by your regular heater.
Thus, you save nothing on your heating bill by a fireplace in one room of a large house.
If the pressure is constant, the heat energy per unit volume remains constant too. I didn’t get it at first:
P=nRT/V = constant
Amount of heat per unit volume, nT/V, is constant. If the temperature doubles, the density halves.
I think this is true, usually, but there are ways to fix this. My folks built their house with a heatilator in the fireplace. They also had the ductwork from the central heat system routed through it, and valves which could control the airflow. The fireplace got most of its air from an outside vent.
In their case, the fireplace was a net increase in heat, and reduced their heating bill considerably. I’m not saying it was a money saver since they had to buy wood, but my Dad’s the type who will have a fire burning anyway, and decided to make it a net heat gain.
Yeah, I thought I corrected it.:mad:
As others have said and in my experience the FP will heat one room very well but not the rest of the house unless you have the fancy ductwork to distribute the heat.
According to that Canadian government web site linked above, the damper makes little difference.
Heating air is nice but not the primary thing. The idea is to heat the tiles. That accomplished, you stop heating. No need for replacing air any more. The tiles heat the room for hours and hours. This is also how heating worked before chimneys: you heat with the door and all other holes open. Stop heating, close the door, wait a while: warm cottage.
As someone who heats regularly several log cabins in Scandinavia, I can confirm that it makes a huge difference whether the hearth is open or not, and whether the smoke is circulated inside the stove or not. But open hearths work, they produce net heat. They warm the room around. Other rooms stay cool, but I’ve never noticed them actually cooling. This maybe be so if you’re heating a single hearth in a manor. When you stop burnng, temperature goes up several degrees in half an hour. Benefits the whole house.
Some fireplaces (like mine!) were built with a little door in the back of the floor that flips open to let in outside air for combustion. That way, the fire doesn’t draw air from the rest of the house. The heat from the fire still only really warms the room it’s in, but at least the other rooms don’t freeze. Also, the house thermostat is about 30’ away in another room, so the furnace still kicks on when necessary.
We don’t really use the fire for heat, though. We light it for atmosphere when we’re in the family room to watch football, or a movie, or hanging out with the family.
Yes it says that. It is obviously incorrect. Try leaving your fireplace damper open all the time and watch what happens to your heating bill. I don’t doubt that fireplaces are inefficient, but the idea of a net loss of heat makes no sense. We can heat almost all of our house from the fireplace. The one large central zone for our baseboard heat does not come on because the fireplace gets the area very hot, and the two smaller zones are isolated with these new-fangled devices we call doors. The fact that some fireplaces are grossly inefficient leading to net heat loss doesn’t mean that all of them are.
I was looking into combustion fireplaces, when I came across this. Are these fireplace eco-friendly and enviromentally friendly? Do they all burn wood?
What’s a combustion fireplace? Aren’t all fireplaces “combustion fireplaces,” in that combustion occurs in them?
fireplaces burn cellulose, either whole wood or wood and/or crop waste pressed into pellets.
burning cellulose has neutral environmental impact.
These are the advanced combustion fireplaces I meant. I notice they were introduced in the 80’s, so they may not be current anymore.
Here is the link I meant to provide
Some have said that fireplaces are good for heating up a room, but not a house.
What about a room that IS the house? Are the furthest corners colder than right in front of the fireplace? What if the furthest corners are really close to the fire?
So, I think that in some cases, a fireplace could effectively heat a [quite small] home.
fireplace inserts are common now a days. they are called inserts because they can be placed into a wood surround and use a metal triple walled chimney pipe which can be in a wood surround, no brick is needed (external to the combustion chamber).