I've tried regular fireplaces, fancy woodstove inserts, and direct vent gas. Direct vent brings all combustion air from outside so that warm interior is not constantly sucked up a chimney. That change is by very far the best efficiency and warmth improvement I've ever experienced. Absolutely worth making sure that no warm house air goes up in smoke.
I appreciate the info you've provided here. I have been considering adding a fresh air intake to my stove which I've operated with no problem for 30 years. All other discussions on the topic seem to conclude there are only benefits to adding an intake. I've decided not to bother, since it might introduce problems to the system. One fact that seems to be lost in the mix is that as far as I know, modern building codes require a fresh air intake coming into the house, usually into the utility/laundry room. Only when my stove is stone cold, and under certain weather conditions, do I have to work to establish a draft. Once it is, and as long as I keep the stove from going completely cold, drafting is no problem.
Great subject! I’m located in the UP of Michigan, our home has a woodstove and two fireplaces. They installed a 4” PVC vent near the woodstove which terminates two inches shy of the bottom of an old butter crock. Works well. It’s air flow I control with a towel, if we don’t allow enough air in we can get smoke in the room. We also can experience a septic smell if the pressure is just right, so we typically crack a window
We have a overpressure switch in our ventilation system. When using the woodstove, the inlet ventilation is working harder than the outlet vents, supporting the additional air consumed by the stowe.
To my way of thinking, the problem with a fire which is taking air for combustion from inside the house is two fold. First you have lit a fire to heat up the air in the house and you are then sucking it into the fire and up the chimney. The second factor is that if there is any lack of air tight sealing in the other rooms in the house, cold air from outside will be sucked into these rooms cooling them down. No wonder kids don't want to go to bed. Their rooms and the bed are freezing in the winter.
@@wlhgmk Don’t forget heat rises. The path of air in my house is up and out. The upstairs isn’t the cold spot. Quite the opposite. The coldest room is downstairs where air has trouble circulating in and out. And that’s true stove or no stove. As I mentioned to another commenter, a bathroom or kitchen vent draws a lot more air out than a wood stove, without a significant supply of heat (a kitchen range doesn’t put off heat like a wood stove).
Correct. Without an outside air duct you have an inefficient fireplace sucking cold air into the house you are supposedly trying to heat. Sucking it into the closed firebox keeps the cold air out of the living space.
It would be cool if they made stoves that used a double walled flue that would let air into the stove and also exhaust smoke. Pre-heat the air that flows into the fire box and no uneven air flow problems as both would have roof openings in the same general area.
@@craigsawyer6453 With the heat of the flue, I don’t think you’d be able to draw cold air down beside it. Might be trying to fight physics and I think it would be hard to create draft. That approach wouldn’t work for all of us with lined masonry chimneys either! Thanks for watching!
@@ProductiveRecreation there are ways to do this, that’s the basics of how heat exchangers work in central air furnaces. That said the reason heat exchangers aren’t used (that I’ve heard) is the cold flue walls build up soot and oils easier and it’s a fire risk. Seems like you could squeeze far more heat out of the wood since ideally you want the gasses leaving the stove/fire to be as cold as possible.
@@ProductiveRecreation I could be wrong but I think that what he describes is basically how direct vent furnaces and on demand water heaters work. Somehow they make it work. It might be that they have a powered fan sucking the flue gases out
@@hugegamer5988 With wood burning you don’t want cold flue gas. If it gets cold and the water vapor condenses, you get nasty creosote buildup, which can lead to chimney fires. It’s a big tradeoff between efficiency and keeping a clean, safe flue. Recommendation is generally not to have single wall stove pipe temps less than 250F during the main part of a burn. The flue gas is about double that temperature.
What about the efficiency losses of encouraging cold air infiltration while you're trying to heat the home? without directing them to the wood stoves air box intake you are just making cold drafts all over the home.
When I sit on the couch, just 8 feet in front of my wood stove insert, I feel very cold air rushing past me. It is the worst and I hate it. It’s so frustrating to have a stove pouring out. massive amounts of hot air but to sit so close to it and feel cold on my back. I think this is the number one reason to get an outside air system set up. For me, it has nothing to do with getting a better draft. As people said, I could just open a little window for that at the beginning. But my house has the opposite problem. I have massive amounts of cold air rushing in at will. My house is old and leaky is an understatement. Should I get an outdoor air kit? Thank you Productive Recreation for making this video with all this theory, but do you recommend an OAK in my case, that is, simply to eliminate drafty cold rushing air? I haven’t done it yet, so I am really looking to know peoples opinion on this.
@@davidmerola3311 I grew up in a house like that for the first 13 years of my life. After we moved, a subsequent owner with $ finally gutted and updated it. Turned out there was no insulation in the downstairs walls. Your stove isn’t pulling more air through than a typical bathroom vent does, and in your situation I don’t think you will see much (if any) difference on the cold draft with an outdoor air connection. Your money is better spent on insulating/air sealing the exterior envelope of the house. I can have 2 stoves burning in my house at the same time with no outdoor air connections and not feel cold draft like you describe, even in the living room in the SE corner of the house with two exterior walls and three windows, which is as far away from the stoves as you can get downstairs. In fact, even with -40F wind chill for two nights last winter, I heated my whole house to a comfortable minimum in the low 60s with just my two wood burning units, and I wasn’t pushing them too hard by burning them extra hot or anything. I just had to get up to put wood in the small one every 3ish hours to keep it going. I won’t do that again unless I have to, but I proved to myself that if the power goes out or the furnace fails and it’s really cold, I can keep us pretty comfortable. To be clear, my house is not draft free - if you sit next to a window you can notice a little cold air infiltration - more in some cases than others (single pane glass with storm windows), however it is nowhere near enough to feel uncomfortable in a room with the stove burning. Plus, where that cool draft is still noticeable, it’s there regardless of whether the stove is burning! For what it’s worth, unless you have a modern high efficiency furnace, oil and gas burners usually don’t draw outside combustion air either.
@ thanks for addressing this for me. Much appreciated. I see the key idea you are trying to show me is that the stove just doesn’t bring in as much air as I thought. I’ve already insulated and completely air sealed the attic. Ok then…time to look into adding insulation in the walls.
@@davidmerola3311 The stove doesn’t pull that much air. An open fireplace with open damper is a different story! If you have an open fireplace in another room start with addressing that. When my freestanding stove was installed and they put the hole for the pipe into the chimney through the brick, the dust sucked up the chimney when they broke through! That’s how much natural airflow (chimney draft) there was. The stove actually limits that flow - close the air control on the stove and that controls the flow into the chimney. Hopefully you have a block off plate in the fireplace above the insert to keep its heat in the house. That would make a difference too. I have my fireplace insert set up with a 6” diameter stainless steel pipe chimney liner from the unit to the roof. The top of the fireplace is otherwise blocked so the only way for air to go up the chimney is through the insert. Just some ideas to check into before you splurge on insulation.
My fireplace insert is set up in the same way, 6” pipe lining up through the chimney. I do not have the chimney flue otherwise blocked off. Did you install that yourself? Or did the dealer you bought from install it? Looks like that is a #1 priority for my situation
It’s usually part of install to plug the rest of the flue with a plate or high temp insulation. I didn’t do it myself. The pipe is usually wrapped in a high temp insulation jacket as well.
I appreciate the nuance, but did you say "assuming an incompressible fluid"? Isn't that the whole reason there is a stovepipe draft to begin with, the gases get hot & expand to be less dense (less compressed), which causes buoyancy compared to the denser gases? An equation of the situation without Temp & density seems like it's missing a major component... Does the wind really blow so hard that air is suctioned in on one side and pushed out the other, regardless of temperature?
@@cyberles8830 Compressible flow just modifies the pressure term with the ratio of specific heats and density of the fluid, so yes it can be overcome by velocity given the same total head (energy) along a streamline. Does the wind often blow that hard and crest sufficiently low pressure zones? Probably not. But the point is that it could, and that would make a dangerous situation. All it has to do is create a sufficiently low pressure zone for gas to flow that way. Therefore the location of the inlet matters a lot. The stove only moves air about like a bathroom vent. Much better to have air exchange on the home than an outdoor connection to a stove. That makes for healthier indoor air too.
Perhaps a Cast-Iron Stovepipe Damper would help answer your question. For every bit of warm air that is going up your stove pipes cold outside air is being drawn into your home to replace the volume.
@@OutDoorAdventures_1907 Unfortunately, you usually can’t do that with an EPA certified stove without voiding the warranty. The stoves are designed for a certain amount of airflow to burn properly to meet EPA emissions requirements. The manual damper means you could get the stove running in a less than optimal condition… of course, if used properly we all know it could make things better… but such is the regulatory environment we live in, for better or worse.
The problem with 'inside air' systems it takes warm inside air & makes the room a lower pressure. This pulls more cold air in the cracks & paths from outside lowering your room temp from this leaky home air flow. The Air inlet should be from a wind immune point in the home usually from below or in a well shrouded place. 11:50 The leaky house argument is totally backwards here. If the draft is pulling cold air into your home what's the point of burning a fire in the first place?
@@salimufari A stove pulls less air than typical bathroom or kitchen range vents. Those would have the same effect of drawing in (cold) outside air, and they aren’t accompanied by a substantial source of heat (a kitchen range doesn’t put off anything like a wood stove). Air exchange isn’t a bad thing. The latest and greatest are the heat exchanging air exchangers, but older houses just leak a little. The stove more than makes up for the heat loss many times over or no one would use them. In my old house, the stove draw is like a drop in a 5 gallon bucket of the air infiltration that happens.
When my dad built our house in 1948, he forgot an air supply for the fireplace. His solution was to open a window 2 inches when we had a fire. Worked fine for 50 years.
You are missing the point entirely. The point is not "will it work?" In your example, you had a 2" by window-width draft of cold air flowing from the window to the stove. Brrr! Might as well put a duct somewhere to direct that air to the stove rather than directing it across the middle of the room.
@@cyberles8830 My Dad always said that newer houses are built way too tight, and that having a little fresh air is good for your health. Once in the 1980's i ended up in the hospital due to indoor pollution in my apartment, so i always make sure my house is not sealed too tight. It is great to breathe fresh air sitting near a slightly opened window. People in perfect health, just don't get it. Sounds crazy to them.
Great video. I took a different approach. I bought a 6 in greenhouse duct fan and use that to bring in filtered air that blows against the back of my stove to extract heat. The outside air pressurizes the old house, gives me a constant draft up the chimney and reduces drafts from outside air infiltration. The fan has 8 speed settings and uses very little power. We are off-grid and run the fan with a solar panel, battery and small inverter.
I see a wood stove behind you. Why not hook up an outside air intake to that stove then report back? Doesn’t seem right to poo poo an idea you’ve never tried…
Forget about inside/outside pressure and “constant value of h” You are using air that has already been heated to burn wood. Then sending it up your chimney. This does not make sense. Why not use cold air to burn your wood and keep the warm air inside your house? Problem solved!
That's the whole premise. Ingited wood, fire needs oxygen to burn better. Air being sucked from under the front door, backdoor, electric outlets, stec. only produces a drafty situation thruout the house. By drawing fresh air to the stove from a duct built specific for the stove, you eliminate that cold draft throughout the house. Path of least resistance. I have crawlpace vents that lead to outside, and I will utilize one of those vents by capturing the air there, and bringing it to the stove with a large diameter metal air tube, by drilling a hole thru the floor, and directing it to the bottom of the stove then up into a square air box per manufacturer's directions.
Why is it that… when people try to explain what’s so wrong with outside air intake systems, it takes a 15 minutei video or some 200 word dissertation? If you can’t tell us in 30 seconds or a few sentences than you’ve got problems
@@craigregan4862 There’s a lot physically going on for how well these systems work (or don’t work). If you want the short answer it’s don’t get outdoor air unless it’s legally required or your stove has draft problems, and even then be careful, because it very well could cause other (potentially worse) problems. I’ll never try it. I don’t have any draft issues. Everything I pointed out about the fluid mechanics holds, and my house leaks plenty. Outdoor air might work fine many days, and might cause a problem on others. That’s an expensive gamble for a non-problem. Traditional 80% efficient oil and gas furnaces don’t use outdoor air either. High efficiency ones typically do, but they aren’t relying on natural draft. They have powered venting which controls the airflow.
So your take is “since I don’t have one you don’t need one”? In addition to the air being used to burn the wood (minimal air usage) we have a strong chimney draft that seems to be sucking warm air out of our house. This pull of air is noticeable along the floors and under the doors of unheated rooms. Maybe outside air will help with strong chimney drafts pulling too much warm inside air up the stack.
@@craigregan4862 No, my take is based on the fluid mechanics of the process and not on whether I have outdoor air. Rather, I don’t have outdoor air because of the physics involved. If your chimney doesn’t draft, outdoor air might help, as I said. Sounds like you don’t have that problem. If your house is that poorly insulated (drafty) then that’s the thing to fix. Do you have an open fireplace or something? Otherwise, a stove actually controls the airflow up a chimney via the air control on it. The airflow shouldn’t be more than about what a bathroom vent does when the stove meters it, with the benefit of lots of heat. For the air setting of a typical burn, those holes on the bottom of my stove are nearly closed, and that’s the only path for air up the chimney. An open fireplace is a different story if the damper is open. That’s why inserts are recommended - to reduce that massive heat loss and keep more of the heat from the fire in the house. The energy efficient way for air exchange in a modern highly insulated (tight) house is a heat exchanging air exchanger for the house, because air exchanges are needed for healthy air. Older houses generally just leak some from every available crack. My house is old and moderately insulated. It isn’t as drafty as you seem to describe. And the drafts we do feel exist with or without the stove.
When I studied Physics we always did labs to support (or debunk) the theoretical process. It was real life observation. Maybe you should experiment with an OAK and submit a lab report to UA-cam!
@@craigregan4862 I don’t need to connect an outside air kit to know the outcome with respect to airflow. It will always go from higher to lower head (pressure). If you have an area of low pressure, air will move toward it. Bernoulli has done the work for us. I’ve also run fluids lab tests with flumes (liquid) and wind tunnels (gas). The principle holds. If you have low pressure develop by the air inlet, it could develop reverse flow. If you eliminate that possibility (a challenge, but maybe possible by burying the inlet), then it could always function as intended. For some people, outside air may help with poor chimney draft. But it also may cause other problems. Having an outsider intake isn’t going to make my leaky house appreciably warmer.
@@imtheonevanhalen1557 Both liquid and gas are fluids, and behave as such. They have no fixed shape and can continuously move and deform in response to forces.
Code Required Residential Air Changes In the US, ASHRAE sets the minimum outdoor air ventilation rates for buildings in the ASNI/ASHRAE Standard 62.1 and 62.2 guidelines. These standards specify how much outdoor air should be brought into a room every hour and are based on occupancy and room size. The US Energy Code and building tightness requires (HRF) Heat Recovery Ventilation or (ERC) Energy Recovery Ventilation. These mechanical devices regulate the ventilation requirements for today's energy-efficient modern homes. When installing a wood-burning stove in these airtight homes, special consideration must be given regarding how the combustion air will be supplied and the combustion gases removed without compromising the building envelope.
I've tried regular fireplaces, fancy woodstove inserts, and direct vent gas. Direct vent brings all combustion air from outside so that warm interior is not constantly sucked up a chimney. That change is by very far the best efficiency and warmth improvement I've ever experienced. Absolutely worth making sure that no warm house air goes up in smoke.
I appreciate the info you've provided here. I have been considering adding a fresh air intake to my stove which I've operated with no problem for 30 years. All other discussions on the topic seem to conclude there are only benefits to adding an intake. I've decided not to bother, since it might introduce problems to the system. One fact that seems to be lost in the mix is that as far as I know, modern building codes require a fresh air intake coming into the house, usually into the utility/laundry room. Only when my stove is stone cold, and under certain weather conditions, do I have to work to establish a draft. Once it is, and as long as I keep the stove from going completely cold, drafting is no problem.
Great subject! I’m located in the UP of Michigan, our home has a woodstove and two fireplaces. They installed a 4” PVC vent near the woodstove which terminates two inches shy of the bottom of an old butter crock. Works well. It’s air flow I control with a towel, if we don’t allow enough air in we can get smoke in the room. We also can experience a septic smell if the pressure is just right, so we typically crack a window
We have a overpressure switch in our ventilation system. When using the woodstove, the inlet ventilation is working harder than the outlet vents, supporting the additional air consumed by the stowe.
To my way of thinking, the problem with a fire which is taking air for combustion from inside the house is two fold. First you have lit a fire to heat up the air in the house and you are then sucking it into the fire and up the chimney. The second factor is that if there is any lack of air tight sealing in the other rooms in the house, cold air from outside will be sucked into these rooms cooling them down. No wonder kids don't want to go to bed. Their rooms and the bed are freezing in the winter.
@@wlhgmk Don’t forget heat rises. The path of air in my house is up and out. The upstairs isn’t the cold spot. Quite the opposite. The coldest room is downstairs where air has trouble circulating in and out. And that’s true stove or no stove. As I mentioned to another commenter, a bathroom or kitchen vent draws a lot more air out than a wood stove, without a significant supply of heat (a kitchen range doesn’t put off heat like a wood stove).
Correct. Without an outside air duct you have an inefficient fireplace sucking cold air into the house you are supposedly trying to heat. Sucking it into the closed firebox keeps the cold air out of the living space.
It would be cool if they made stoves that used a double walled flue that would let air into the stove and also exhaust smoke. Pre-heat the air that flows into the fire box and no uneven air flow problems as both would have roof openings in the same general area.
@@craigsawyer6453 With the heat of the flue, I don’t think you’d be able to draw cold air down beside it. Might be trying to fight physics and I think it would be hard to create draft. That approach wouldn’t work for all of us with lined masonry chimneys either! Thanks for watching!
@@ProductiveRecreation there are ways to do this, that’s the basics of how heat exchangers work in central air furnaces. That said the reason heat exchangers aren’t used (that I’ve heard) is the cold flue walls build up soot and oils easier and it’s a fire risk. Seems like you could squeeze far more heat out of the wood since ideally you want the gasses leaving the stove/fire to be as cold as possible.
@@ProductiveRecreation I could be wrong but I think that what he describes is basically how direct vent furnaces and on demand water heaters work.
Somehow they make it work. It might be that they have a powered fan sucking the flue gases out
@@hugegamer5988 With wood burning you don’t want cold flue gas. If it gets cold and the water vapor condenses, you get nasty creosote buildup, which can lead to chimney fires. It’s a big tradeoff between efficiency and keeping a clean, safe flue. Recommendation is generally not to have single wall stove pipe temps less than 250F during the main part of a burn. The flue gas is about double that temperature.
What about the efficiency losses of encouraging cold air infiltration while you're trying to heat the home? without directing them to the wood stoves air box intake you are just making cold drafts all over the home.
Excellent content. The story's moral is to burn a well-seasoned hardwood and stay out of the annoying cold air draft.
When I sit on the couch, just 8 feet in front of my wood stove insert, I feel very cold air rushing past me. It is the worst and I hate it. It’s so frustrating to have a stove pouring out. massive amounts of hot air but to sit so close to it and feel cold on my back. I think this is the number one reason to get an outside air system set up. For me, it has nothing to do with getting a better draft. As people said, I could just open a little window for that at the beginning. But my house has the opposite problem. I have massive amounts of cold air rushing in at will. My house is old and leaky is an understatement. Should I get an outdoor air kit? Thank you Productive Recreation for making this video with all this theory, but do you recommend an OAK in my case, that is, simply to eliminate drafty cold rushing air? I haven’t done it yet, so I am really looking to know peoples opinion on this.
@@davidmerola3311 I grew up in a house like that for the first 13 years of my life. After we moved, a subsequent owner with $ finally gutted and updated it. Turned out there was no insulation in the downstairs walls. Your stove isn’t pulling more air through than a typical bathroom vent does, and in your situation I don’t think you will see much (if any) difference on the cold draft with an outdoor air connection. Your money is better spent on insulating/air sealing the exterior envelope of the house. I can have 2 stoves burning in my house at the same time with no outdoor air connections and not feel cold draft like you describe, even in the living room in the SE corner of the house with two exterior walls and three windows, which is as far away from the stoves as you can get downstairs. In fact, even with -40F wind chill for two nights last winter, I heated my whole house to a comfortable minimum in the low 60s with just my two wood burning units, and I wasn’t pushing them too hard by burning them extra hot or anything. I just had to get up to put wood in the small one every 3ish hours to keep it going. I won’t do that again unless I have to, but I proved to myself that if the power goes out or the furnace fails and it’s really cold, I can keep us pretty comfortable. To be clear, my house is not draft free - if you sit next to a window you can notice a little cold air infiltration - more in some cases than others (single pane glass with storm windows), however it is nowhere near enough to feel uncomfortable in a room with the stove burning. Plus, where that cool draft is still noticeable, it’s there regardless of whether the stove is burning! For what it’s worth, unless you have a modern high efficiency furnace, oil and gas burners usually don’t draw outside combustion air either.
@ thanks for addressing this for me. Much appreciated. I see the key idea you are trying to show me is that the stove just doesn’t bring in as much air as I thought. I’ve already insulated and completely air sealed the attic. Ok then…time to look into adding insulation in the walls.
@@davidmerola3311 The stove doesn’t pull that much air. An open fireplace with open damper is a different story! If you have an open fireplace in another room start with addressing that. When my freestanding stove was installed and they put the hole for the pipe into the chimney through the brick, the dust sucked up the chimney when they broke through! That’s how much natural airflow (chimney draft) there was. The stove actually limits that flow - close the air control on the stove and that controls the flow into the chimney. Hopefully you have a block off plate in the fireplace above the insert to keep its heat in the house. That would make a difference too. I have my fireplace insert set up with a 6” diameter stainless steel pipe chimney liner from the unit to the roof. The top of the fireplace is otherwise blocked so the only way for air to go up the chimney is through the insert. Just some ideas to check into before you splurge on insulation.
My fireplace insert is set up in the same way, 6” pipe lining up through the chimney. I do not have the chimney flue otherwise blocked off. Did you install that yourself? Or did the dealer you bought from install it? Looks like that is a #1 priority for my situation
It’s usually part of install to plug the rest of the flue with a plate or high temp insulation. I didn’t do it myself. The pipe is usually wrapped in a high temp insulation jacket as well.
Yes, yes you do. No damn drafts that way
So, crack a window a little bit when you're firing up a stove to prevent backdraft, gotcha.
I appreciate the nuance, but did you say "assuming an incompressible fluid"? Isn't that the whole reason there is a stovepipe draft to begin with, the gases get hot & expand to be less dense (less compressed), which causes buoyancy compared to the denser gases? An equation of the situation without Temp & density seems like it's missing a major component...
Does the wind really blow so hard that air is suctioned in on one side and pushed out the other, regardless of temperature?
@@cyberles8830 Compressible flow just modifies the pressure term with the ratio of specific heats and density of the fluid, so yes it can be overcome by velocity given the same total head (energy) along a streamline. Does the wind often blow that hard and crest sufficiently low pressure zones? Probably not. But the point is that it could, and that would make a dangerous situation. All it has to do is create a sufficiently low pressure zone for gas to flow that way. Therefore the location of the inlet matters a lot. The stove only moves air about like a bathroom vent. Much better to have air exchange on the home than an outdoor connection to a stove. That makes for healthier indoor air too.
How does one regulate a passive air intake system?
A Damper
Perhaps a Cast-Iron Stovepipe Damper would help answer your question. For every bit of warm air that is going up your stove pipes cold outside air is being drawn into your home to replace the volume.
@@OutDoorAdventures_1907 Unfortunately, you usually can’t do that with an EPA certified stove without voiding the warranty. The stoves are designed for a certain amount of airflow to burn properly to meet EPA emissions requirements. The manual damper means you could get the stove running in a less than optimal condition… of course, if used properly we all know it could make things better… but such is the regulatory environment we live in, for better or worse.
The problem with 'inside air' systems it takes warm inside air & makes the room a lower pressure. This pulls more cold air in the cracks & paths from outside lowering your room temp from this leaky home air flow. The Air inlet should be from a wind immune point in the home usually from below or in a well shrouded place.
11:50 The leaky house argument is totally backwards here. If the draft is pulling cold air into your home what's the point of burning a fire in the first place?
@@salimufari A stove pulls less air than typical bathroom or kitchen range vents. Those would have the same effect of drawing in (cold) outside air, and they aren’t accompanied by a substantial source of heat (a kitchen range doesn’t put off anything like a wood stove). Air exchange isn’t a bad thing. The latest and greatest are the heat exchanging air exchangers, but older houses just leak a little. The stove more than makes up for the heat loss many times over or no one would use them. In my old house, the stove draw is like a drop in a 5 gallon bucket of the air infiltration that happens.
When my dad built our house in 1948, he forgot an air supply for the fireplace. His solution was to open a window 2 inches when we had a fire. Worked fine for 50 years.
You are missing the point entirely. The point is not "will it work?" In your example, you had a 2" by window-width draft of cold air flowing from the window to the stove. Brrr! Might as well put a duct somewhere to direct that air to the stove rather than directing it across the middle of the room.
@@cyberles8830 My Dad always said that newer houses are built way too tight, and that having a little fresh air is good for your health. Once in the 1980's i ended up in the hospital due to indoor pollution in my apartment, so i always make sure my house is not sealed too tight. It is great to breathe fresh air sitting near a slightly opened window. People in perfect health, just don't get it. Sounds crazy to them.
Great video. I took a different approach. I bought a 6 in greenhouse duct fan and use that to bring in filtered air that blows against the back of my stove to extract heat. The outside air pressurizes the old house, gives me a constant draft up the chimney and reduces drafts from outside air infiltration. The fan has 8 speed settings and uses very little power. We are off-grid and run the fan with a solar panel, battery and small inverter.
Are you Cody from Cody's lab's twin brother?
@@ConReese No 😆
I see a wood stove behind you. Why not hook up an outside air intake to that stove then report back? Doesn’t seem right to poo poo an idea you’ve never tried…
Forget about inside/outside pressure and “constant value of h”
You are using air that has already been heated to burn wood. Then sending it up your chimney.
This does not make sense.
Why not use cold air to burn your wood and keep the warm air inside your house?
Problem solved!
That's the whole premise. Ingited wood, fire needs oxygen to burn better. Air being sucked from under the front door, backdoor, electric outlets, stec. only produces a drafty situation thruout the house. By drawing fresh air to the stove from a duct built specific for the stove, you eliminate that cold draft throughout the house. Path of least resistance. I have crawlpace vents that lead to outside, and I will utilize one of those vents by capturing the air there, and bringing it to the stove with a large diameter metal air tube, by drilling a hole thru the floor, and directing it to the bottom of the stove then up into a square air box per manufacturer's directions.
Why is it that… when people try to explain what’s so wrong with outside air intake systems, it takes a 15 minutei video or some 200 word dissertation? If you can’t tell us in 30 seconds or a few sentences than you’ve got problems
@@craigregan4862 There’s a lot physically going on for how well these systems work (or don’t work). If you want the short answer it’s don’t get outdoor air unless it’s legally required or your stove has draft problems, and even then be careful, because it very well could cause other (potentially worse) problems. I’ll never try it. I don’t have any draft issues. Everything I pointed out about the fluid mechanics holds, and my house leaks plenty. Outdoor air might work fine many days, and might cause a problem on others. That’s an expensive gamble for a non-problem. Traditional 80% efficient oil and gas furnaces don’t use outdoor air either. High efficiency ones typically do, but they aren’t relying on natural draft. They have powered venting which controls the airflow.
So your take is “since I don’t have one you don’t need one”? In addition to the air being used to burn the wood (minimal air usage) we have a strong chimney draft that seems to be sucking warm air out of our house. This pull of air is noticeable along the floors and under the doors of unheated rooms. Maybe outside air will help with strong chimney drafts pulling too much warm inside air up the stack.
@@craigregan4862 No, my take is based on the fluid mechanics of the process and not on whether I have outdoor air. Rather, I don’t have outdoor air because of the physics involved. If your chimney doesn’t draft, outdoor air might help, as I said. Sounds like you don’t have that problem. If your house is that poorly insulated (drafty) then that’s the thing to fix. Do you have an open fireplace or something? Otherwise, a stove actually controls the airflow up a chimney via the air control on it. The airflow shouldn’t be more than about what a bathroom vent does when the stove meters it, with the benefit of lots of heat. For the air setting of a typical burn, those holes on the bottom of my stove are nearly closed, and that’s the only path for air up the chimney. An open fireplace is a different story if the damper is open. That’s why inserts are recommended - to reduce that massive heat loss and keep more of the heat from the fire in the house. The energy efficient way for air exchange in a modern highly insulated (tight) house is a heat exchanging air exchanger for the house, because air exchanges are needed for healthy air. Older houses generally just leak some from every available crack. My house is old and moderately insulated. It isn’t as drafty as you seem to describe. And the drafts we do feel exist with or without the stove.
When I studied Physics we always did labs to support (or debunk) the theoretical process. It was real life observation. Maybe you should experiment with an OAK and submit a lab report to UA-cam!
@@craigregan4862 I don’t need to connect an outside air kit to know the outcome with respect to airflow. It will always go from higher to lower head (pressure). If you have an area of low pressure, air will move toward it. Bernoulli has done the work for us. I’ve also run fluids lab tests with flumes (liquid) and wind tunnels (gas). The principle holds. If you have low pressure develop by the air inlet, it could develop reverse flow. If you eliminate that possibility (a challenge, but maybe possible by burying the inlet), then it could always function as intended. For some people, outside air may help with poor chimney draft. But it also may cause other problems. Having an outsider intake isn’t going to make my leaky house appreciably warmer.
Air is a liquid? No, air is a gas that sometimes behaves as a liquid.
@@imtheonevanhalen1557 Both liquid and gas are fluids, and behave as such. They have no fixed shape and can continuously move and deform in response to forces.
Code Required Residential Air Changes
In the US, ASHRAE sets the minimum outdoor air ventilation rates for buildings in the ASNI/ASHRAE Standard 62.1 and 62.2 guidelines.
These standards specify how much outdoor air should be brought into a room every hour and are based on occupancy and room size.
The US Energy Code and building tightness requires (HRF) Heat Recovery Ventilation or (ERC) Energy Recovery Ventilation.
These mechanical devices regulate the ventilation requirements for today's energy-efficient modern homes.
When installing a wood-burning stove in these airtight homes, special consideration must be given regarding how the combustion air will be supplied and the combustion gases removed without compromising the building envelope.
If you have enough leaks in your doors and windows you will have no problems...which is most homes in the US