Clay Flues for High-Tech Heaters Charleston SC

More efficient gas furnaces in Charleston extract more heat from the flue gases before they are vented into the chimney. Although these furnaces conserve fuel, they also cause corrosive condensation problems.

Frazier's Ironworks
(843) 577-0830
1932 Milford St
Charleston, SC
 
Williams Machine And Tool Company
(843) 767-3095
4753 Franchise St
Charleston, SC
 
Allied Metal Fabricators
(803) 754-2515
700 Sharpe Rd
Columbia, SC
 
Frazier's Ironworks
(843) 577-0830
1932 Milford St
Charleston, SC
 
Owen Steel Company Inc
(803) 251-7680
727 Mauney Dr
Columbia, SC
 
Crane And Associates
(843) 277-9914
2671 Orchid Avenue
North Charleston, SC
 
Cedar Terrance Barber Shop
(803) 783-2813
6420 Garners Ferry Rd Ste R
Columbia, SC
 
Vulcraft Inc
(803) 732-5557
1 Harbison Way Ste 223
Columbia, SC
 
Steel Fab
(803) 727-1020
1 Harbison Way Ste 201
Columbia, SC
 
Spectrum Fabrication/Metal Fabricators
(803) 776-1886
1421 Pineview Dr
Columbia, SC
 

Clay Flues for High-Tech Heaters

Provided By:

Source: Masonry Construction
Publication date: February 1, 1992

By Jim Buckley

Abstract: Newer, more efficient gas furnaces extract more heat from the flue gases before they are vented into the chimney. Although these furnaces conserve fuel, they also cause corrosive condensation problems. When flue gases enter a chimney at just over the dew point temperature, they quickly cool to below the dew point, then condense into water and corrosive acids. The acidic condensate eats through stainless steel, aluminum, and galvanized flue liners and leaks through the butt joints of clay flue tiles. It's not a little problem. The problem isespecially acute in masonry chimneys with flues too big for the efficient new gas furnaces.SEEKING SOLUTIONSA good solution seems simple enough. If these new furnaces are vented into smaller, 4- or 6-inch diameter tile flue liners, most of the effluent will stay above the dew point and exit the chimney in vapor form. Shiplapped or belled joints in these smaller flues will keep any condensed effluent inside the liner. The gas utilities and gas furnace manufacturers seem blind to the obvious advantages of clay tile liners in masonry chimneys. The National Fuel Gas Code (NFPA 54 and ANSI Z223.1) currently is being revised so as to deemphasize, if not prohibit, masonry flues in favor of "listed" metal and plastic liners.

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