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Author Topic: Radiant Garage Heater -exhaust vent routing with elevated heater? CSA B149.1-15  (Read 914 times)

Offline mike_scoby

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Hi, I had a garage heater installed by a tech that works for the manufacturer.

It is a Calcana CAL-40 radiant tube heater, drawing air in on one side of the garage, and venting to the other side of the garage. It is a fan assisted appliance. 

PDF Manual is available here.

Due to the ceiling line being reduced on one side of the garage by the way the roof was constructed,  the vent was routed down and out where it exits under the garage soffit.




The vent is single wall Type B as supplied by the manufacturer has a 4"x3" reducer from the output end of the heater and then 3" straight pipe with 2x 90° elbows.

The manufacturers install instruction shows that 2 elbows are allowed on the vent in order to drop the vent down to have the heater elevated above the soffit line.

The city inspector came out for the permit approval, and pointed out that there cannot be additional straight pipe in between the elbows.  In other words my garage heater is too high and would need to be dropped down.  The problem with this is that the man door into the house would be in the way (Or the heater would be in the way, depending on your priorities!  ;D)

Since it is only 20" of straight pipe in between the elbows I don't see any concern with the installation, however, I have been looking through CSA B149.1-15 in hopes that it would show an allowable height drop for the vent below the heater and haven't found anything to suggest this allowance.  In Annex C of CSA B149.1-15,  Table C.1 (which I think is applicable by the note in Figure C.1)  Link to PDF of older revised version CSA B149.1-10 I found online the height shown only starts at +6 ft.  I'm not sure if this implies even +2 feet up and out would be unacceptable?

I'm wondering if 2 elbows to go down-and-out is allowed as per the install manual, then this would need to be approved under CSA B149.1. 

Is anyone aware of somewhere in the CSA codes that would help me out?   Is there a way that I can leave the system as is, and measure the actual vent pressure loss, or show the city the calculation of the difference in pressure loss with the added 20" straight pipe?

If I dropped the heater down to the same level as where the vent terminates, theoretically according to CSA B149.1-15 I should be able to add 2 more 90 degrees and route the vent up and around the door and then back down?

Offline Porcupinepuffer

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The venting requirements for that particular appliance is special and none of the annex's from the codebook apply to it. There may be stiffer clearances and more than 2 screws required by the codebook. The manufacturers instructions on what is and isn't allowed for venting has the details. Unless it says you can have that 20" or more in between the elbows, you may need to make changes.  I don't see it listing a maximum or minimum length of pipe that can go between those elbows.  They do seem to imply the need to go back to back or shorter by cutting them.

Offline bster352

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It says to remove excess material from male end. Allow 2" extra material to put in female end of tube. It does not say cut 45. If you go by the picture you are pooched. is there any more information on pg 31? I think you need clarification from the manufacturer and a letter stating you can use the 20" of vent pipe.


Offline Sergroum

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I've never installed one of these, so I'm obviously missing on a lot of background information. I'm just curious though, why couldnt have that unit be reversed? As in, have the combustion air be drawn from the pipe that needs to be dropped down, and have the exhaust come out on the other side where the intake is at now. It doesnt look like that one needed to drop down. What am I missing?