Thread: Fireplace Chimney

I always get a bit confused by fireplace chimney height/clearance levels and I'm not sure if this one is wrong. I saw this at a house yesterday. The chimney is for a fireplace that has a gas log set installed and could be converted back to a wood burning unit easily. The top of the chimney flue is below the adjacent sidewall of the 2nd floor level of the house and less than 10 feet from the sidewall (somewhere around 9.5 feet).

Is this a defect?

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Top of the chimney needs to be 3 feet above the penetration point, and 2 feet above anything within 10 feet. Not sure if your example meets the 10 foot rule.

Originally Posted by Nick Ostrowski

I always get a bit confused by fireplace chimney height/clearance levels and I'm not sure if this one is wrong. I saw this at a house yesterday. The chimney is for a fireplace that has a gas log set installed and could be converted back to a wood burning unit easily. The top of the chimney flue is below the adjacent sidewall of the 2nd floor level of the house and less than 10 feet from the sidewall (somewhere around 9.5 feet).

Is this a defect?

.
Yep,

Ms. Sisson Nailed IT!
.

Helpful diagram

Originally Posted by Welmoed Sisson

Top of the chimney needs to be 3 feet above the penetration point, and 2 feet above anything within 10 feet. Not sure if your example meets the 10 foot rule.

Counting shingle tabs indicates the chimney might be about 7'-8' from that side wall.

Originally Posted by Nick Ostrowski

I always get a bit confused by fireplace chimney height/clearance levels and I'm not sure if this one is wrong. I saw this at a house yesterday. The chimney is for a fireplace that has a gas log set installed and could be converted back to a wood burning unit easily. The top of the chimney flue is below the adjacent sidewall of the 2nd floor level of the house and less than 10 feet from the sidewall (somewhere around 9.5 feet).

Is this a defect?

Interesting picture, highlighted features not mentioned, requiring details which may be of more significant clearance concerns.

I like your use of colors HG. Maybe you could punctuate your points further with some Batman-isms like "POW!!" or "BLAMMO!!!" or "KERSPLATTT!!!!".

I used my Ultra Stinger which is a a wisp over 11.75" to measure out the distance to the sidewall. It came in at 9' - 9.5'.

Thinking cap Nick (for the big one).What is in the red circle which is closer to the chimney flue than the siding on the wall and far less than 3ft lower than the chimney flue termination serving the gas appliance of unknown description now installed in the formerly solid fuel fireplace?Forced air inlet?!? Hmmm.

The Riddler?

SMACKO!!!!!!

Originally Posted by H.G. Watson, Sr.

Thinking cap Nick (for the big one).What is in the red circle which is closer to the chimney flue than the siding on the wall and far less than 3ft lower than the chimney flue termination serving the gas appliance of unknown description now installed in the formerly solid fuel fireplace?Forced air inlet?!? Hmmm.

.
A 120 Volt AC Unit. . SHAZAM!!!
.
* but they blow.
** conditioned air from the dwelling envelope.

Originally Posted by Billy Stephens

.
A 120 Volt AC Unit. . SHAZAM!!!
.
* but they blow.
** conditioned air from the dwelling envelope.

Too dense, no help for you.

Originally Posted by Billy Stephens

.
A 120 Volt AC Unit. . SHAZAM!!!
.
* but they blow.
** conditioned air from the dwelling envelope.

Originally Posted by H.G. Watson, Sr.

Too dense, no help for you.

.
* you saying A 120 Volt AC Unit is a Forced Air Inlet ?
** or it's Hard to communicate with more than a 20 point IQ Spread?
*** I'll try to Slow Down for You.

I used my Ultra Stinger which is a a wisp over 11.75" to measure out the distance to the sidewall.

A measuring tape is awful handy in such situations.

Originally Posted by Billy Stephens

.
* you saying A 120 Volt AC Unit is a Forced Air Inlet ?
** or it's Hard to communicate with more than a 20 point IQ Spread?
*** I'll try to Slow Down for You.

First of all you have no idea if the slide-out-chassis air conditioning unit pictured is powered by 120 or 240V, so I'll let that one slide for the moment. What is pictured is most likely a "slide-out-chassis" type air conditioner - the probability is quite high that same has a fresh air vent which may be opened. Whether or not it is operated solely in a fully closed position, or if it (unlikely) is without a fresh air vent, there isn't a single such unit which is "hermetically sealed" when installed. It is abundantly and obviously suggested by what presents in the image provided, is that whatever has been installed through the pictured exterior wall, that same in its oriientation and proximity to the pictured chimney, and most importantly, the chimney's flue termination, may be significantlys CLOSER in horizontal distance and less than three feet below the flue termination of what has been reported to serve a gas-fired appliance of unknown distinction and identification, which has been installed in a previously solid-fuel-burning fireplace of unknown distinction and identification.



Next, you are apparently "without a clue" yet again (recall recent discussions regarding your ignorance of what a coil or tank-in-tank indirect fired water heater actually is, and your inability to SEE, let alone ACCEPT the indicators presented in photographs and diagrams as to some of the tell-tale distinctions between same and a water storage tank!).

Most, if not all, portable-, window-, slide-out-chassis-, and through-the wall (requires separate wall-sleeve) "type" air conditioners have a fresh air vent which can be opened/closed. Apparently you are only familiar with operating same with the vent in the closed postion and/or those select few which may not have a fresh air vent control.

We (hopefully yourself included) also have the obvious shared experience of the reality that few, if any, existing site-built structures are constructed as hermetically sealed or maintained as such. Infiltration, negative pressures created, stack effect (within structures as a whole, por portions therein or thereof, such as wall cavities, etc.) as well as prevailing winds, wind sheer, eddys, etc. can effect both the infiltration of the products of combustion or incomplete combustion to the room behind that wall or the structure, as well as the possible effects upon the gravity venting of that chimney flue termination.

Furthermore it is not unreasonable to consider the circumstances where for example, a gas-fired decorative appliance may be in use in the fireplace containing room below that lower level roof and chimney while at the same time above, in the room at the upper level adjacent to that exterior wall, the installed-in-the-wall appliance may be operating in a ventilating (i.e. fresh air vent OPEN) MODE!

If you cannot grasp the concept, nor the concept that the equipment installed at the wall may furthermore be subjected in too-close-a-proximity to the products of combustion and incomplete products of combustion (exiting the chimney flue termination) being mechanically drawn to through its chassis would be detrimental to same.

Hence the requirements both of the theoretical (unidenfied) presumed "listed" gas-fired & vented (decorative, log set, etc.) equipment installed in the former solid-fuel-burning theoretical (unidenfied as to masonry, factory, stove, insert) fireplace itself and the requirements that chimney terminations or gas vent terminations be at least three feet above and 10 ft away from mechanical "forced air inlets".

The chimney termination appears to be significatly less than three feet above the air conditioner chassis louvers - and based upon the information provided by Nick regarding the horizontal distance from the exterior wall - suggests that those openings are quite probably just as if not more significantly closer than 10 ft horizontally to same.

Of additional significance would be the topography of the area, the orientation of the planes to the prevailing winds, and what may be present regarding adjacent and overhanging (i.e. tree canopy) vegitation, regarding proper distances and elevations for chimney termination. The 2-3-10 rule is a minimum standard which as the codes further explain (such as NFPA 211) additional adjustments may be necessary to assure proper draft, etc.

So, yes Billy, I am suggesting that the apparent slide-out-chassis (airconditioner, or other) unit pictured installed in the adjacent exterior wall, when the presumed and most likely present (fresh air) VENT is in other than the CLOSED position (and even if in the closed, but in anything other than an hermetically sealed condition - and that's unlikely, since by design there is most always some leakage), and while the FAN is operating, would be a performing as a FORCED AIR INTAKE CONDITION, and therefore the pictured is quite probably and indeed a "FORCED AIR INLET" The proximity is determined by the origin of the inlet, not to the "force" producing mechanism (fan); and its relationship to the chimney (flue) termination. The presence is determined not by when or if it is operated as a forced air inlet, but by the installation/existance/presence and ability to be operated in such a manner so as to mechanically draw outside air into the structure BY DESIGN, operation, and function; hence the exclamation point notation to the photographed area encircled when posting about details and information regarding both circled areas and proximity to chimney termination was lacking, and quite possibly more determinative as to the defectiveness of the current conditions as well as the suggested future hypothetical condition (of returning fireplace of unknown distinction to solid-fuel burning operations).


The chimney's flue termination must be at least three feet ABOVE and at least 10 feet away from the louvered chassis openings. The equipment (manufacturer's instructions) for itself may dictate additional clearances, as may the orientation, prevailing winds, etc. from same (products of combustion, and incomplete products of combustion, negative effects on the coil, corrosion, errosion, etc.).


Unknown what is present up at the attic gable or in the attic itself - or its proximity to the questioned chimney flue termination; fan driven, equipment, or otherwise to the apparent ventilation inlet, hence the question mark.



So, KAPOW! SLOOSH!, ZOK!!, CRASH!, WHAMM!!, OOOOFF!; POW!!; AND VRONK! ZLONK! SPLATT! CLANK!; OR Duh! ShaZam!, lights out! ZAPPP!! as the case may be.

Originally Posted by H.G. Watson, Sr.

First of all you have no idea if the slide-out-chassis air conditioning unit pictured is powered by 120 or 240V, so I'll let that one slide for the moment. What is pictured is most likely a "slide-out-chassis" type air conditioner - the probability is quite high that same has a fresh air vent which may be opened. Whether or not it is operated solely in a fully closed position, or if it (unlikely) is without a fresh air vent, there isn't a single such unit which is "hermetically sealed" when installed. It is abundantly and obviously suggested by what presents in the image provided, is that whatever has been installed through the pictured exterior wall, that same in its oriientation and proximity to the pictured chimney, and most importantly, the chimney's flue termination, may be significantlys CLOSER in horizontal distance and less than three feet below the flue termination of what has been reported to serve a gas-fired appliance of unknown distinction and identification, which has been installed in a previously solid-fuel-burning fireplace of unknown distinction and identification.



Next, you are apparently "without a clue" yet again (recall recent discussions regarding your ignorance of what a coil or tank-in-tank indirect fired water heater actually is, and your inability to SEE, let alone ACCEPT the indicators presented in photographs and diagrams as to some of the tell-tale distinctions between same and a water storage tank!).

Most, if not all, portable-, window-, slide-out-chassis-, and through-the wall (requires separate wall-sleeve) "type" air conditioners have a fresh air vent which can be opened/closed. Apparently you are only familiar with operating same with the vent in the closed postion and/or those select few which may not have a fresh air vent control.

We (hopefully yourself included) also have the obvious shared experience of the reality that few, if any, existing site-built structures are constructed as hermetically sealed or maintained as such. Infiltration, negative pressures created, stack effect (within structures as a whole, por portions therein or thereof, such as wall cavities, etc.) as well as prevailing winds, wind sheer, eddys, etc. can effect both the infiltration of the products of combustion or incomplete combustion to the room behind that wall or the structure, as well as the possible effects upon the gravity venting of that chimney flue termination.

Furthermore it is not unreasonable to consider the circumstances where for example, a gas-fired decorative appliance may be in use in the fireplace containing room below that lower level roof and chimney while at the same time above, in the room at the upper level adjacent to that exterior wall, the installed-in-the-wall appliance may be operating in a ventilating (i.e. fresh air vent OPEN) MODE!

If you cannot grasp the concept, nor the concept that the equipment installed at the wall may furthermore be subjected in too-close-a-proximity to the products of combustion and incomplete products of combustion (exiting the chimney flue termination) being mechanically drawn to through its chassis would be detrimental to same.

Hence the requirements both of the equipment itself and the requirements that chimney terminations be three feet above and 10 ft away from mechanical air inlets.

The chimney termination appears to be significatly less than three feet above the air conditioner chassis louvers - and based upon the information provided by Nick regarding the horizontal distance from the exterior wall - suggests that those openings are quite probably just as if not more significantly closer than 10 ft horizontally to same.

Of additional significance would be the topography of the area, the orientation of the planes to the prevailing winds, and what may be present regarding adjacent and overhanging (i.e. tree canopy) vegitation, regarding proper distances and elevations for chimney termination. The 2-3-10 rule is a minimum standard which as the codes further explain (such as NFPA 211) additional adjustments may be necessary to assure proper draft, etc.

So, yes Billy, I am suggesting that the apparent slide-out-chassis (airconditioner, or other) unit pictured installed in the adjacent exterior wall, when the (fresh air) VENT is in other than the CLOSED position (and even if in the closed, but in anything other than an hermetically sealed condition), and while the FAN is operating, would be a qualified FORCED AIR INTAKE CONDITION, and therefore the pictured is quite probably and indeed a "FORCED AIR INLET", hence the exclamation point notation to the photograph.

The chimney's flue termination must be at least three feet ABOVE and at least 10 feet away from the louvered chassis openings. The equipment (manufacturer's instructions) for itself may dictate additional clearances, as may the orientation, prevailing winds, etc. from same (products of combustion, and incomplete products of combustion, negative effects on the coil, corrosion, errosion, etc.).

Unknown what is present up at the attic gable or in the attic itself - or its proximity to the questioned chimney flue termination; fan driven, equipment, or otherwise to the apparent ventilation inlet, hence the question mark.

Wow, take 1/2 a Breath, ( or let them fingers cool Down )

Don't take yourself so seriously. ( and Spell Check )

So If that is a AC with a Fresh Air intake and If Someone is downstairs and using the Gas Fired Appliance at the exact same time Someone upstairs is using the ( If the AC has one ) fresh air intake Then The Attached Circles, Arrows Diagram ( you do know how to color) would Show a Chimney Code Violation.

So if All those If's are present then you have a Case.
* As a Meir Mortal I can only Report what is Provable.

Originally Posted by Billy Stephens

Wow, take 1/2 a Breath, ( or let them fingers cool Down )

Don't take yourself so seriously. ( and Spell Check )

So If that is a AC with a Fresh Air intake and If Someone is downstairs and using the Gas Fired Appliance at the exact same time Someone upstairs is using the ( If the AC has one ) fresh air intake Then The Attached Circles, Arrows Diagram ( you do know how to color) would Show a Chimney Code Violation.

So if All those If's are present then you have a Case.
* As a Meir Mortal I can only Report what is Provable.

Nope. If the chimney flue termination is less than 3 ft above the louvers and/or less than 10 ft away from the louvers it is a defective condition. No one ever has to operate either for it to be so.

Originally Posted by H.G. Watson, Sr.

Nope. If the chimney flue termination is less than 3 ft above the louvers and/or less than 10 ft away from the louvers it is a defective condition. No one ever has to operate either for it to be so.

.
If It has a Fresh Air Intake.
.

Well, since no one except the OP was there, it can't even be stated that there is an air conditioner present. Maybe, maybe not.

I've seen abandoned slide-out chassis frames sticking out of walls, but the wall has been sealed up after the guts were removed from the inside because the siding repair exceeded the skill level of the occupant.
Ergo, no contaminated air is entering the home due to the lack of a hermetically sealed system.

Moral of the story, HG, is to not cry wolf without learning all the facts. I wasn't there. You weren't there. We have no idea what any of that looks like.
I'm not saying your wrong, but I ain't saying your right...

Dom.

The wall mounted AC unit in the pic is intact and appeared to be an operable unit for the 2nd floor master bedroom. I would not expect that AC unit and the fireplace to be in operation at the same time but clearances are clearances.

Swap out the gas logs with a gas direct vent--problem solved. You could say install ventfree logs but I don't view them as a viable option.

The two within ten rule was really to get the flue gas outlet away from adverse wind effect. Wind tends to bounce off nearby sidwalls affecting flow.

Originally Posted by H.G. Watson, Sr.

So, KAPOW! SLOOSH!, ZOK!!, CRASH!, WHAMM!!, OOOOFF!; POW!!; AND VRONK! ZLONK! SPLATT! CLANK!; OR Duh! ShaZam!, lights out! ZAPPP!! as the case may be.

.
.......
.

Billy,

I thought Watson was about to get in the groove with: A-Wop-bop-a-loo-lop a-lop-bam-boo ... ... Little Richard Tutti Frutti lyrics - YouTube

Or even into this groove: A wop ba-ba lu-mop a wop bam boom

Originally Posted by Bob Harper

Swap out the gas logs with a gas direct vent--problem solved. You could say install ventfree logs but I don't view them as a viable option.

The two within ten rule was really to get the flue gas outlet away from adverse wind effect. Wind tends to bounce off nearby sidwalls affecting flow.

Bob,

Nick posed question returning fireplace "back to" solid fuel. I'm not sure your proposed solutions address that.

Additionally, the chimney termination 3 ft above within 10 ft rule regarding termination above-away from forced air inlets is applicable and as I recall, has less to do with wind deflection and more to do with avoiding drawing flue gasses etc. into the structure and interfering with proper draft up the chimney (hot side) in absence of significant wind.

Originally Posted by Jerry Peck

Billy,

I thought Watson was about to get in the groove with: A-Wop-bop-a-loo-lop a-lop-bam-boo ... ... Little Richard Tutti Frutti lyrics - YouTube

Or even into this groove: A wop ba-ba lu-mop a wop bam boom

.
Whatever It is I Like it !
* Hey at least it has Color.
.

Originally Posted by Dom D'Agostino

Well, since no one except the OP was there, it can't even be stated that there is an air conditioner present. Maybe, maybe not.

I've seen abandoned slide-out chassis frames sticking out of walls, but the wall has been sealed up after the guts were removed from the inside because the siding repair exceeded the skill level of the occupant.
Ergo, no contaminated air is entering the home due to the lack of a hermetically sealed system.

Moral of the story, HG, is to not cry wolf without learning all the facts. I wasn't there. You weren't there. We have no idea what any of that looks like.
I'm not saying your wrong, but I ain't saying your right...

Dom.

Wasn't crying wolf, was addressing the posts of others following my original post and denoted photo, which if you read carefully you will see exactly what I initially said when I posted the notated photo. The subsequent was responsive to the subsequent 'blinders on" posts, ignoring the fresh air ventilation fan only or otherwise use of the wall mounted unit.

And as Nick conceded:

[quote] The wall mounted AC unit in the pic is intact and appeared to be an operable unit for the 2nd floor master bedroom. I would not expect that AC unit and the fireplace to be in operation at the same time but clearances are clearances. {/quote]

Regardless, the proximity to something apparently closer than the exterior wall and apparently not at least three feet below the chimney termination is what was being addressed.



P.S. The Batman remarks were also responsive as was the included illustrations...as Nick invited same, with his sarcastic remarks to my having used more than one color to highlight the photograph:

like your use of colors HG. Maybe you could punctuate your points further with some Batman-isms like "POW!!" or "BLAMMO!!!" or "KERSPLATTT!!!!".

So much for less is more, and simple graphics, the peanut gallery argues there is not fresh air ventilation on such a unit, then disputes that using ventilation only would never take place when a gas appliance decorative or otherwise installed in the fireplace below would never happen.

Sure it could, even if the wall unit was being used in AC or dehumidifying mode up on the higher floor, absolutely. Gas appliances in same are more for looks rather than efficient let alone effective heating sources. Anyway, seems the youngsters are unaware that older folks, yes, not just post menopausal women (yep, certain meds can also have that effect on us Men), sometimes have difficulty with regulating their confort/temperature. Older folks and skinny folks (especially the recently skinny) can catch a chill when all around are sweating and pulling their clothes off.

Lower level feels cool, somebody wants to see a fire, decorative appliance or otherwise downstairs, and the upstairs retaining warmth from the day, stale air, humid from a bath, cooking smells, or that hotflash effect, and wants some fresh air to air out the room above. Happens all the time.

Anyway, I've been in many a home where the AC was running full-tilt and the decorative gas appliances and/or gas logs were flickering away behiind glass doors and scores of folks being entertained, fed, and 'watered'. Simultaneous operation is not beyond the imagination, but the prohibition is not dependant on the operation it is upon the existance of a forced air inlet, not on the use of same.

Wap Bop- A -do-Bop - A-bing, bang, boom!

HG, that 3 ft clearance above any forced air inlet within 10 ft. is for mechanical draft systems M1804.2.6

You could refer to ASHRAE which requires intakes 10 ft. away from bad air and 25 ft away from hazardous atmospheres.

With woodsmoke, yes, this could be a very real problem due to odors. Gas fumes will dissipate long before they get near that wall.

Originally Posted by H.G. Watson, Sr.

Additionally, the chimney termination 3 ft above within 10 ft rule regarding termination above-away from forced air inlets

is applicable and as I recall, has less to do with wind deflection and more to do with avoiding drawing flue gasses etc

. into the structure and interfering with proper draft up the chimney (hot side) in absence of significant wind.

'
Lets Expand this rant.

There's a Crack in the Cladding within 10 ft and lower than 3ft of the termination of a Second Story Chimney that has Gas Logs installed.

On the other side of this Crack is a Personal Size Table Top Fan. Is this Crack Now a Forced Air Inlet ?

Will the Combustion Fumes of the Gas Logs Infiltrate the Dwelling to the determent of the unsuspecting inhabitants ? Or be measurable when or If they actually make it to the top of said chimney?

WHAT IS WE TO DO !

.

KERPOWWW!!!!!

For one thing, outdoor air and fumes are not going to enter a building unless the entry point is under negative pressure WRT outdoors. Since we're talking about chimney exhaust that is usually above the Neutral Pressure Plane of the building so it hard--not impossible but hard to get chimney exhaust back into the buildig up there. Now, what is close to the smoke and often under negative pressure is the adjacent flue when you have multi-flue chimneys. This is where having a top damper may prevent recirculation of heater exhaust back down the Fp flue into the home for ex.

Mechanical intakes are another matter but typically they don't draw from more than a few feet and by then most if not all of the exhaust fumes will have dissipated.

"Sigh of Relief"

Thanks Bob,

Now the only thing we have to worry about Grand Maw's Hot Flashes is if the Drapes are Closed.
* and the Trip Hazard..