Not all class A is created equal nor UL listed

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CrappieKeith

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It was found through UL testing that the standard 1,700 degree Class A chimney failed during a chimney fire. The standard Class A metal chimney is the standard for oil furnaces ,not wood furnaces.
The 1700 degree insulation is not designed to withstand the possible 2,200 degrees found in chimney wall temperatures. Upon failure of the insulation, the temperatures of the outside wall of the chimney would far surpass the required clearances to combustibles. If a second chimney fire occurred before the chimney is replaced ,the possibility of a house fire is a strong possibilty,possibly causing bodily harm or death to the occupants inside the home.


NFPA 211 Standard for Chimneys,Fireplaces,Vents and Solid Fuel-Burning Appliances

2006 Edition

Annex A Explanatory Material

A.3.3.32.1.3 Type HT Factory-Built,Residential-Type and or Building Heating Appliance Type Chimney.

Chimneys disignated as Type HT are listed for venting flue products not exceeding 1,000* (538C) continous. In addition,they comply with the 10 minute-2,100*(1149*C) temperature test requirements of UL 103, Standard
for factory built chimneys for residential type and building heating appliance.
Such test requirements were developed to stimulate the effects of a chimney fire. Type HT Chimneys are required on certain controlled-combustion solid fuel-burning appliances because such appliance are after associated with a higher liklihood of creosote buildup and associated occurrence of chimney fires.


The 1,700 degree(cheap chimney) that is being sold is not UL listed for solid fuel burning appliances.

Paragraph 36.4 of the UL 103 states" All chimneys claiming HT approval must be marked accordingly".



The reason for this post is through my expierences as of late. I've been seeing folks buying these discounted pipings and thinking they are saving money when in fact they are jeparodizing their home and family safety.
I just thought you all should be aware.
 
Last edited:
Keith,

Do you have a non exhaustive list of chimneys that are listed properly for wood burning appliances? Which do you reccomend?

Don
 
All that info checks out with my code books; 2006 International Residential Coce (IRC).

Not only are they jepardizing their family's safety but that of first responders as well.
 
Keith,

Do you have a non exhaustive list of chimneys that are listed properly for wood burning appliances? Which do you reccomend?

Don

I do not have a list.
I will tell you that whatever you buy it should be marked on the product "HT".
I would reccomend either Selkirk or Simpsons Duravent products.

As a company we chose DuraVent to offer our customer base.
 
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