I own a fireplace with a blower type mechanism that sucks air in from the bottom and seem to direct the air near the coal bed. While this makes the fire larger and easier to get really hot, I would like to think that this does not increase the efficiency at all. Wouldn’t the blower increase the amount of air that gets heated and expelled through the chimney? BTW, I do not think that there is an outlet where the heated air is expelled back into the room. Searching the internet brings up mixed results. So whats the straight dope, to blow or not?
Ok - nothing definitive here, so if you’d like, move along. However, I’m wondering how you might define efficiency in your case. It seems as if you’re burning up your wood at a faster rate. If it also gets hotter, then maybe you’re heating the room to a higher temperature. In other words, the energy is being released quicker but it is also raising your internal temperature more. What is the overall efficiency of such a system? Hard to say. I believe it rests on the question of how much hotter the wood burns, and how much of that energy comes into your house and is retained. What is your experience? Does it seem as if the house gets warmer and stays warm?
i don’t understand what you are saying or you are mistaken.
there are firplace devices that take room air and pass it around the firebox to be heated. this air never goes into the firebox or chimney. the blower spreads the air so the room(s) get hotter farther from the fireplace.
modern enclosed fireplaces (glass doors) use outside air for the combustion. this keeps warm air in your house because house air doesn’t feed the fire and go up the chimney.
CC, Thanks for the response. My standard for efficiency is whatever is the most economical. I am trying to save on heating costs during this cold snap we are having in the SE USA. My heating system consists of a heat pump with electric resistive heating as a backup. The heat pump cannot draw enough heat from the outside air (mid-low 20s) and the resistive heating gets VERY expensive. The area that is heated by the fireplace is also vary large, so temperature changes happen slowly. I don’t want to use the fireplace blower if the heat loss through the chimney is greater than the increased heat from the ‘blown’ fire.
I think what I have does differ. I thought I was getting a blower that heated the room air around the firebox and returned it to the room, but it seems that I have a simple, no doors, no outside air feed, fireplace. When the blower is on, I can feel it draw air in through the vent underneath the fireplace, so it is taking in room air, blowing it across the fire, and then out the chimney (I presume). I wonder if the radiated heat from the larger fire is greater than the heat lost from the increased air passing over the fire and out the chimney.
I’m going to guess that the blower is intended to be used to either bring a fire back to life when it’s dieing down and you add fresh wood or to get the fire going good when you first start.
I’ve heard that some fireplaces have a blower to supplement a poor chimney draft - this sounds like it’s purpose unless… It was made to blow air around the firebox but the firebox has deteriorated and allow that air to get into the combustion area.