Where would you vent the kitchen exhaust? Wall or roof?

[jmbfestool]

these openings really kill energy efficiency. a normal sized fan could ruin months of work air sealing and insulating a passive house.

A flapper door(s) seals the opening when not in use.  You're making it sound like a window staying open all the time.

As for JMB and his comment, all I can say is you've still got a lot to learn (probably the hard way), and I'm sure my words will have no effect on you.  Maybe in 20 years I'll be able to say, "I told you so."  Maybe I should say this to JMB, with a fireplace, there needs to be oxygen and if there isn't enough "make up air" from the room, you need a fresh supply of air so the oxygen isn't depleted from the room.  Living quarters : room : fire place : people xygen .... get it?  The problem isn't just carbon monoxide produced during combustion.  It's also about having a continuous correct balance of oxygen, carbon dioxide and nitrogen in the immediate surrounding area for people to breathe and survive.

I know what the vents are for but for normal or small burners you do not need Vents on a existing building in your living room on new building they make you do it regardless what size why? whats different?. 

A fire wont light if their is not enough air a normal house has enough draft to supply a burner .  So your saying the fire will use all the oxygen in the room which we humans need correct? well what does fire need? the same as humans like you said Oxygen so the fire will just burn out.  So IF your fire wont light and/or smoke starts to come into the room instead of  going up the chimney THEN you need to get a vent as their is not enough fresh air to for the chimney to draw the smoke away  this can be seen as a good sign as your house is well insulated and sealed but most house are NOT and thus no need for a air vent.      So I would try and light the fire if it goes well then why have a air vent?!?!?! As it clearly is getting enough fresh air!  If it wasnt it would just not light or your room will just be a cloud of smoke.

JMB

 

[jmbfestool]

ken
even with a flap door on the pipe there is no u value to the traped air. the trap door is there to stop the wind blowing in. the pipe still acts as a thermal funnel sucking out the heat. these are worse than an open window in that you cant properly close them
i was specifically talking about passive design. the very smallest gap in the the building envelobe.the same applies to normal buildings. you cant ever see most of the gaps that engineers are chasing when they do an airtightness test on a passive home.

as for the jmb comments. i would never install a fireplace in a home without a vent. ken is right in what he is saying but in the uk most houses have a special vent that allows outside air to be pulled in under the fire box and up the chimney. this is a pipe under the floor . this is a more energy effiecient system than the 4 inch hole in the wall.

in my country they removed the requirment fot the hole in the wall vent as they are way to over used. people had them in every room. one 4inch vent is enough ventillation to supply a 4 bedroom house with 5 ocupents. now we use small vents in the pvc windows (1/4inch by 6inch slots).
do the math and you will see

The house I was working on was doing a Draft test where they stick a MASSIVE fan on the front doors and it sucks all the air out!   We had built 7 brand new houses he started the thing up and got his numbers up and said wow this is bad alot of draft coming into this house.  

I told him all the houses had Air vents in the living rooms and all the windows had vents and their was a few extractors in each house bathroom toilets  he told me to go round a duck tape all of these things as when they do the test they dont take them into consideration!

As I went round duck taping all these up!  Man the living room vent was blowing air in like a pertol blower!  So I ducked tape all that up!  It was funny as carpet up stairs started floating as air was being drawn from under the skirting board(kick boards) lifting the carpet.   He asked me if I had ducked tape all the vents and I said yes he redid the test and said the house is average!     I was like well thats rubbish cus when I remove all the duck tape it will be below average he said YIP but thats how it goes!

So I do know kinda what I am talking about!  Houses often have plenty of fresh air to keep a normal size fire going with out the need of having a air vent!

Also when I went and bought a new fire place I asked the bloke what size fire can I have with out needed to install a air Vent and he told me  (I forgot what KW) but he said most of the ones he had on show will work with out air vent!    

So........  I dont know Ken but Im still a live! we have 2 fire burners in this house and they have both been running at the same time not often but they have and I had enough oxygen to breath.       I still believe if a fire burns well then you don't need a vent as its getting its oxygen obvisouly.      Its dead simple a fire just wont burn if it doesnt get enough fresh air it will just keep dying out and your room will just be full of smoke.

JMB

 

[jmbfestool]

Q. Do I need an Air Brick for extra ventilation?

A. In the EU, regulations require that gas fires with an input of less than 7 kiloWatts (which includes most of our Inset Gas Fires) do not require additional ventilation by way of air bricks provided they are installed according to manufacturer's specification. (Regulations may vary in countries outside the European Union - please check).
ww.castironfires.com/gasfires-faq.html
http://www.limestonefires.com/gasfires-faq.html

Most houses have enough adventicious ventilation natural ventilation through cracks holes and gaps through doors etc. New buildings CAN be more air tight but larger rooms and smaller fires can still be okay!   Meaning no additional ventilation is required! I dont know what spillage test is but I know what its for! its for testing if the house has enough adventicious ventilation and if not then a air brick would be needed!   So.... 20 years later Ken you wont be able to of told me so! cus I told you so now.

So like I said I would test first as just sticking a air vent because you think its the proper way is actually the incorrect way as all you would be doing is making a insulated house which is suppose to be energy efficient very inefficient due to to much ventilation.

JMB

 

[mastercabman]

  So your saying the fire will use all the oxygen in the room which we humans need correct? well what does fire need? the same as humans like you said Oxygen so the fire will just burn out. 

JMB

Right!  BUT,    If there's no oxygen,you will pass out before the fire will!!!  Then when the fire can no longer burn there will be a lot of smoke.Witch you will not be able to breath anyway.

 

[Ken Nagrod]

JMB,

Fireplace manufacturers and building inspectors don't give a rats bleep how many air leaks a house has.  You are required to have a certain size intake and exhaust as there is no way to determine whether the unit will be installed in a "tight" house, a "loose" house or something in between.  If the air is supplied from within the house, then you must maintain enough fresh air circulating through the house to keep it safe for occupants while the fireplace is in use.  Like Mastercabman stated, you'll lose the oxygen before the fire does and you'll be dead.  Don't be a gambling man on that one.  Even the strongest man in the world can be put on his butt real fast without enough energy to lift a tissue if the oxygen around him is lowered - hypoxia.  That's why the healthiest of people have died in fires or going into a mine shaft or holding tank where the oxygen level is too low to sustain human life.  Muscles need oxygen to work and if they don't have it, they won't.  Same with the brain.  Confusion will set in.  You might not be able to think that you need to get up and out, open a window, whatever.

If a house is drafty, has air leakage, fix it.  It's not an excuse to use that for an air supply source.  As for the "I told you so" I was referring to your cavalier attitude towards building permits, approvals and certified construction practises that will eventually catch up with you in one or more ways such as fines, lawsuits and a bad reputation among the building community in your area.  I hope none of these happens to you.

 

[Alan m]

JMB,

Fireplace manufacturers and building inspectors don't give a rats bleep how many air leaks a house has.  You are required to have a certain size intake and exhaust as there is no way to determine whether the unit will be installed in a "tight" house, a "loose" house or something in between.  If the air is supplied from within the house, then you must maintain enough fresh air circulating through the house to keep it safe for occupants while the fireplace is in use.  Like Mastercabman stated, you'll lose the oxygen before the fire does and you'll be dead.  Don't be a gambling man on that one.  Even the strongest man in the world can be put on his butt real fast without enough energy to lift a tissue if the oxygen around him is lowered - hypoxia.  That's why the healthiest of people have died in fires or going into a mine shaft or holding tank where the oxygen level is too low to sustain human life.  Muscles need oxygen to work and if they don't have it, they won't.  Same with the brain.  Confusion will set in.  You might not be able to think that you need to get up and out, open a window, whatever.

If a house is drafty, has air leakage, fix it.  It's not an excuse to use that for an air supply source.  As for the "I told you so" I was referring to your cavalier attitude towards building permits, approvals and certified construction practises that will eventually catch up with you in one or more ways such as fines, lawsuits and a bad reputation among the building community in your area.  I hope none of these happens to you.

this explains the jmb speak

 

[Ken Nagrod]

Huh?

 

[jmbfestool]

Der is a Test to test if der is enough  adventicious ventilation (natural ventilation)

The Spillage Test  
This test checks if the flu draws enough to take the smoke and fumes.  This means their is enough fresh air ventilation coming in to the room as it wouldn't draw otherwise.  Sooo explained:

The test is carried out with the windows SHUT, if it passes then the next port of call is to investigate EVERY potential extract fan which could effect the test result, ie paddle fan on any ceiling, tumble drier or cooker hood if they are extracting to outside, any other extractor fan in any other room, IF the test(s) ALL pass then it is safe to tick the box as PASS.  So no extra ventilation required! No big hole drilling in your lounge basically!

IF the test Fails!   You can OPEN up a window and if it Passes with a window OPEN.  THEN a permanent Vent would need to be installed as this indicates the house does not have enough  adventicious ventilation so a vent is needed.     If the test still Fails with the window OPEN then their might be a problem with the flu or something and it will need to be check over and corrected and then retested untill PASS.  

JMB Speak over and out!

 

[Ken Nagrod]

Der is a Test to test if der is enough  adventicious ventilation (natural ventilation)

The Spillage Test 
This test checks if the flu draws enough to take the smoke and fumes.  This means their is enough fresh air ventilation coming in to the room as it wouldn't draw otherwise.  Sooo explained:

The test is carried out with the windows SHUT, if it passes then the next port of call is to investigate EVERY potential extract fan which could effect the test result, ie paddle fan on any ceiling, tumble drier or cooker hood if they are extracting to outside, any other extractor fan in any other room, IF the test(s) ALL pass then it is safe to tick the box as PASS.  So no extra ventilation required! No big hole drilling in your lounge basically!

IF the test Fails!  You can OPEN up a window and if it Passes with a window OPEN.  THEN a permanent Vent would need to be installed as this indicates the house does not have enough  adventicious ventilation so a vent is needed.    If the test still Fails with the window OPEN then their might be a problem with the flu or something and it will need to be check over and corrected and then retested untill PASS. 

JMB Speak over and out!

Looks like I've coined a term that's become a monster.  Who would have thunk?  [big grin]

 

[Deansocial]

JMB,

Fireplace manufacturers and building inspectors don't give a rats bleep how many air leaks a house has.  You are required to have a certain size intake and exhaust as there is no way to determine whether the unit will be installed in a "tight" house, a "loose" house or something in between.  If the air is supplied from within the house, then you must maintain enough fresh air circulating through the house to keep it safe for occupants while the fireplace is in use.  Like Mastercabman stated, you'll lose the oxygen before the fire does and you'll be dead.  Don't be a gambling man on that one.  Even the strongest man in the world can be put on his butt real fast without enough energy to lift a tissue if the oxygen around him is lowered - hypoxia.  That's why the healthiest of people have died in fires or going into a mine shaft or holding tank where the oxygen level is too low to sustain human life.  Muscles need oxygen to work and if they don't have it, they won't.  Same with the brain.  Confusion will set in.  You might not be able to think that you need to get up and out, open a window, whatever.

If a house is drafty, has air leakage, fix it.  It's not an excuse to use that for an air supply source.  As for the "I told you so" I was referring to your cavalier attitude towards building permits, approvals and certified construction practises that will eventually catch up with you in one or more ways such as fines, lawsuits and a bad reputation among the building community in your area.  I hope none of these happens to you.

all new housing in the uk is pressure tested to meet a certain standard. Build tight ventilate right

 

[leakyroof]

I'm with Brice on this one.  I vote for going out the wall even with the known stud locations not adding up easily for the OP with regards to where they want to run their duct pipe.
The shortest path generally works best for venting. Least amount of turns or fittings always leads to least amount of trouble for me if it's done right the first time. Also, I HATE roof leaks , so I avoid adding more roof penetrations if at all possible. I have a 1200 CFM exhaust fan for our kitchen. Dual blower set-up, adjustable for speed. Very powerful at full on setting.
 Now, builders and others in the construction trades are starting to look at setting up uniform make-up air guidelines so that everyone can follow along easily. This was a recent topic over at Fine Homebuilding, with high performance kitchen exhaust hoods like mine being a real problem in new, very tight homes.   Our unit is run on a 8" round duct, straight out of the hood and one 90 degree turn out the ajoining brick wall on the 2nd floor where we live[old 2 flat]. Heavy screen riveted to the outside flap/dampner to keep birds from building a nest in it.  No roof leaks to worry about, and it was installed in 1996.  Cutting the hole through the brick wall wasn't bad either back then from what I remember.
Our old home[almost 100 yrs] isn't tight at all, BUT, we still need to crack the bathroom window open when the kitchen fan is at high speed or close to it ,since it will pull the bathroom plumbing stack gases DOWN the bathroom fan vent pipe and into the bathroom if no windows are open in the house for makeup air.  Basically, the bathroom fan that was installed in 2000 by a HVAC contractor during other HVAC work is just too close to the main stack once you get out on the roof.
Since the tiny CFM output of the bath fan can't really compete with the kitchen fan, it's a struggle to just leave the bathroom fan on while working in the kitchen and stop the 'backdraft' with the bath fan alone.  Opening a window is cheaper and works well........... [blink]