# Learning resources



## Alan (Jun 18, 2008)

I've mentioned before that i'm always up for learning new stuff. 

Yesterday I looked at one of those tiny houses. Whomever built the thing decided that he didn't want to do the plumbing and turned the thing over to the owner. The guy installed a small gas tankless water heater and it has some of that 3" corrugated dryer flex bent and squished into something that resembles a fitting more than 90 degrees, and out the side wall.


My admission : I'm not particularly well versed in water heater venting. My previous place of employment was in such an area where gas systems were all private because of ground movement, and most of the water heaters were electric anyway. I don't think I installed a single gas heater until we started doing tankless and even then, those were condensing units that used pvc.

This one has some kind of a metal exhaust connector and draws air from inside the room. I understand that there is some kind of requirement for air drawn in based on BTU load, which is fine, and calculable based on the code book. What I don't understand are the different types of metal exhaust piping, how to identify the difference between them, different parts and pieces that are available. 

Maybe this isn't rocket science, but I am in unfamiliar territory and I want to do something to make myself more confident in this aspect of my job. I think admitting to myself that this is a potentially hazardous situation and erring on the side of caution is a good start. :vs_laugh: 

What kind of resources are out there for self educating?


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## Cagey57 (Mar 2, 2018)

There are "Archive" pdf files of the IPC, IRC and IMC available on line. Too big to attach but just do a search for "IMC Archive".

The rest of it is usually brand specific when it comes to some of the combination Intake/Exhaust vent configurations.

The codes list the required combustion air needed based on BTU of the appliance.

Hope this helps.


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## Alan (Jun 18, 2008)

Here's a question since I'm not familiar with "normal" practices in terms of gas venting and intake.

Regardless of the calculations below what kind of Louver, grate, etc do you guys typically use for a sidewall air intake?

This situation I have is a water heater installed but not hooked up except for an illegal - af vent for the thing. There is no makeup air for this thing to be installed indoors. I've decided that I can move the heater, vent it through the roof with b-vent, and then use the existing hole for makeup air. It will have to be enlarged, because right now it's only 4" DIA and the unit is pulling 80,000 BTU.

My calculations say I need one square inch per 3,000 btu which comes out to ~26 square inches, except the installation manual for this thing says no smaller than 9x12.

:vs_cool:


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## Debo22 (Feb 15, 2015)

For a through the wall style I’d go by an hvac supply house and pick up a return air grill.
https://www.google.com/search?q=sta...ent=safari&dlnr=1&sei=IJ0QW-HqM4-S0PEPmJ2GuAo


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## Alan (Jun 18, 2008)

I found a small ish 12x12 gable end louvered vent for the outside.

Something like this : https://hw.menardc.com/main/items/media/AIRVE001/ProductLarge/1475728.jpg

Should do the same job I guess. 

A lot more thought should have been put into this project before they called me or called me to put some thought into the project before it got as far along as it did. So here we are making a hole in the side wall for air intake. 

lain:


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