God bless you ; You teach the best ;. It was hard to understand the gas code for me. With your videos ;I understood. Well done ; And please continue 👏👏👏👏
Hello Sir , we have a tightly sealed house with 38000 btuh water heater and 60000 btuh non direct vent high efficiency furnace . We have a fairly small furnace room say (10 foot by 7 foot area ) Im planning to make a duct for fresh air intake from side of house. As per the numbers it should be a 4 inch diameter, but since my furnace space is confined( less than 50 cu ft per 1000btuh, would it make sense to have a bigger fresh air duct of 6 inch instead to let in more air? Are there any cons to that?? Would it make our basement too cold ?? Any help is appreciated
Hey thanks for the videos they are really helpful. I was wondering, For the enclosure example, if it were installed in an Air Tight building instead of a Leaky type would I use tables 8.1/8.2 to size the air supply or would I just use clause 8.2.6? Thanks agian.
@@Funboyy123 Your inspector is not going to like that. Buildings are not built loose anymore, and any old building that is renovated will be sealed airtight. Bring your air in from the outdoors. The only way around this is to use direct vented appliances.
@@MathematicPlumber It's a practice question for my g2 test. Thankfully not a real installation. I guess its not a bad question since it got me digging for the answer.
@@Funboyy123 Is there anyway you could email me the actual question? Now I am curious. I think I am missing some important information about the question. With venting, the details in the question can change everything. Hopefully I am not too late. (I won't just give you the answer, but I might be able to point you in the right direction here) mathematicplumber@gmail.com
if i get 136 sq inch how how know what size is my grill cause is normally rectangular how can i get the math for that in red seal exam they ask you for grill size rectangular or square ft ej 12x8 or 6x12 or 12x12
In order to answer this question with certainty I would need to know exactly how the question is phrased. I am going to go the simple route though. If the question is referring to loose construction 400,000 BTU or less: 136 divided by 12 = 11.8ish 12 x 12 is likely the answer. But if the 136 square inches is "free area opening" then it could be larger.
@@MathematicPlumber im just relating with that example cause normally in red seal they ask you to shoose based on inch eather rectangular or square grill but i believe you answer my question , you sre just the best teacher my red seal is two week and i think you will own that certificated no me ,thank
Hi, I have a question about grills. I would really appreciate it if you could give me some advice. If you have a ventilation grill on the outside wall (at the end of a duct or outside an enclosure), the grill needs to have the same free area as the duct so that it is not causing a restriction to the air flow. I am coming across questions where the grill is described has having a free area of 75%. Does that mean that 75% of the grill is free area the rest is slats and the structure of the grill? so If you needed a free area of 40 sq in, but only 75% of that is free area, then you would need to increase the area (size) of the grill by 25%? so the grill would be enlarged to 40 x 1.25 = 50 sq in, giving a free area of 40 sq in? The code is not very clear on this, Thanks allot
You are correct, the grills do add restriction to the airflow. How you deal with this is fairly simple though. You need to find the grill manufacturer's specifications where they will tell you the free area of each of their different grills. Choose one that is close. (It likely will not be exact)
Old comment, but incase someone else comes here looking for an answer - The grille manufacturer will have an AK factor in their information, usually a decimal, that you multiply by to be able to correct for it. In this case 14"x10" would give you 140sq" rather than the 136sq" required, that additional surface area will overcome the resistance added by the face of the grille.
I have a question regarding louvres / grilles also, if the air supply is determined to require 350 sq in of free air and the louvre specified for the wall opening has a free air area of 60% how would I calculate the size of the louvre? Is it simply 350 sq in x 1.4 giving 490 sq in louvre size ?
First of all you will need to redo your math: 350 in sq divided by 0.6 = 583.33 in sq Now you need to determine the height of your grill. I will assume it is 12" 583.33 in sq divided by 12" = 48.61" (This grill would be abnormally huge) Typically we use grill manufacturer's sizing charts to determine this. They will list their grills in size (dimensions) and how much free air opening they are rated for.
@@MathematicPlumber Thank You … I am studying to sit my Red Seal exam from over in the UK , I have been a Domestic Gas service and repair engineer for 16 years and looking to move over to Canada as a journeyman Gas Fitter, I was a bit unsure on the question that I posted as its in the BCIT course books but not very clear about sizing of louvres … much appreciate your reply
@@MathematicPlumber Hi I just wanted to say a massive Thank You for all your videos, I have since flown to Canada and passed my Class B gas fitter exam and have a job offer / sponsor, Just this week I have received an Invitation to Apply for PR on the BC PNP programme and I could not be happier, without your tutorials it would have been more difficult to achieve the results I have… Keep on keeping on mate and if you’re ever in Whistler I’ll buy you a few pints
God bless you ;
You teach the best ;.
It was hard to understand the gas code for me.
With your videos ;I understood.
Well done ;
And please continue 👏👏👏👏
Hello Sir , we have a tightly sealed house with 38000 btuh water heater and 60000 btuh non direct vent high efficiency furnace . We have a fairly small furnace room say (10 foot by 7 foot area ) Im planning to make a duct for fresh air intake from side of house. As per the numbers it should be a 4 inch diameter, but since my furnace space is confined( less than 50 cu ft per 1000btuh, would it make sense to have a bigger fresh air duct of 6 inch instead to let in more air? Are there any cons to that?? Would it make our basement too cold ?? Any help is appreciated
Hey thanks for the videos they are really helpful. I was wondering, For the enclosure example, if it were installed in an Air Tight building instead of a Leaky type would I use tables 8.1/8.2 to size the air supply or would I just use clause 8.2.6? Thanks agian.
Thanks Tyler! Use table 8.1 / 8.2 and bring in a regular combustion air duct.
Just realizing the question I was having a problem on is stating the air is to be taken from indoors. That's where I was having my problem. Thanks.
@@Funboyy123 Your inspector is not going to like that. Buildings are not built loose anymore, and any old building that is renovated will be sealed airtight. Bring your air in from the outdoors. The only way around this is to use direct vented appliances.
@@MathematicPlumber It's a practice question for my g2 test. Thankfully not a real installation. I guess its not a bad question since it got me digging for the answer.
@@Funboyy123 Is there anyway you could email me the actual question? Now I am curious. I think I am missing some important information about the question. With venting, the details in the question can change everything. Hopefully I am not too late. (I won't just give you the answer, but I might be able to point you in the right direction here)
mathematicplumber@gmail.com
if i get 136 sq inch how how know what size is my grill cause is normally rectangular how can i get the math for that in red seal exam they ask you for grill size rectangular or square ft
ej 12x8 or 6x12 or 12x12
In order to answer this question with certainty I would need to know exactly how the question is phrased.
I am going to go the simple route though. If the question is referring to loose construction 400,000 BTU or less:
136 divided by 12 = 11.8ish
12 x 12 is likely the answer. But if the 136 square inches is "free area opening" then it could be larger.
@@MathematicPlumber im just relating with that example cause normally in red seal they ask you to shoose based on inch
eather rectangular or square grill but i believe you answer my question , you sre just the best teacher my red seal is two week and i think you will own that certificated no me ,thank
Hi, I have a question about grills. I would really appreciate it if you could give me some advice. If you have a ventilation grill on the outside wall (at the end of a duct or outside an enclosure), the grill needs to have the same free area as the duct so that it is not causing a restriction to the air flow. I am coming across questions where the grill is described has having a free area of 75%. Does that mean that 75% of the grill is free area the rest is slats and the structure of the grill? so If you needed a free area of 40 sq in, but only 75% of that is free area, then you would need to increase the area (size) of the grill by 25%? so the grill would be enlarged to 40 x 1.25 = 50 sq in, giving a free area of 40 sq in? The code is not very clear on this, Thanks allot
You are correct, the grills do add restriction to the airflow. How you deal with this is fairly simple though. You need to find the grill manufacturer's specifications where they will tell you the free area of each of their different grills. Choose one that is close. (It likely will not be exact)
Old comment, but incase someone else comes here looking for an answer - The grille manufacturer will have an AK factor in their information, usually a decimal, that you multiply by to be able to correct for it.
In this case 14"x10" would give you 140sq" rather than the 136sq" required, that additional surface area will overcome the resistance added by the face of the grille.
I have a question regarding louvres / grilles also, if the air supply is determined to require 350 sq in of free air and the louvre specified for the wall opening has a free air area of 60% how would I calculate the size of the louvre? Is it simply 350 sq in x 1.4 giving 490 sq in louvre size ?
First of all you will need to redo your math:
350 in sq divided by 0.6 = 583.33 in sq
Now you need to determine the height of your grill. I will assume it is 12"
583.33 in sq divided by 12" = 48.61" (This grill would be abnormally huge)
Typically we use grill manufacturer's sizing charts to determine this. They will list their grills in size (dimensions) and how much free air opening they are rated for.
@@MathematicPlumber Thank You … I am studying to sit my Red Seal exam from over in the UK , I have been a Domestic Gas service and repair engineer for 16 years and looking to move over to Canada as a journeyman Gas Fitter, I was a bit unsure on the question that I posted as its in the BCIT course books but not very clear about sizing of louvres … much appreciate your reply
@@MathematicPlumber Hi I just wanted to say a massive Thank You for all your videos, I have since flown to Canada and passed my Class B gas fitter exam and have a job offer / sponsor, Just this week I have received an Invitation to Apply for PR on the BC PNP programme and I could not be happier, without your tutorials it would have been more difficult to achieve the results I have… Keep on keeping on mate and if you’re ever in Whistler I’ll buy you a few pints
@@67bristolian If I make it to Whistler I'll take you up on that. After I send A-Line and Dirt Merchant with my bike of course.