Direct Fired Heating cETL vs usETL rating

[goodwrench1]

Hello,

I am continuing to do research on Direct Fired Heating Units such as

http://www.rapidengineering.com/hvac/direct_fired/4000/hvac_direct_fired_4000_overview.html

and

http://www.trane.com/CPS/uploads/userfiles/productpdfs/mua-prc007-en_12042009.pdf

I have found so far that these units that can operate in recirculate mode can only be certified by the ETL (Edison Testing Lab, now Intertek)for use in the United States, the only way to be certified for Canada is 100% fresh air mode only, no recirculation.

Does the ETL test ANSI, NFPA, etc... standards or do they have their own standards that would differ for Canada? I have wrote to ETL but so far no response.

Seems like a safety issue that may be overlooked for the US but is addressed by Canadian regulators possibly?



I had posted this thread earlier this year for a little background

http://www.eng-tips.com/viewthread.cfm?qid=263886

Thanks for all of your help!

 

[AbbyNormal]

I believe the Canadian Gas Utilization codes prohibit recirculation with direct fired equipment

The way we build has a far greater impact on our comfort, energy consumption and IAQ, than any HVAC system we install

 

[ChrisConley]

Recirculation is allowed for specific instances, paint-booths comes to mind. It is provisional of the space not being occupied when the unit is operational. It's one of the two methods used to increase the maximum temperature rise you can get out of a direct-fired MUA.