Articles > Planning Your Direct Vent Pipe Installation


9 Oct 2006

 

Direct Vent Pipe: Planning Your Installation
Courtesy of Dura-Vent:
 
Direct vent gas appliances are "sealed combustion systems." That means the air for combustion is delivered to the appliance through the venting system from outside. As a result, direct vent appliances do not consume warm indoor air for combustion, and they are not subject to oxygen starvation, poor draft and other problems associated with "tight" energy efficient homes. With sealed direct vent systems, all combustion by-products are safely vented out through the venting system, eliminating fumes, water moisture, and indoor air contamination.
 
Direct Vent Stove
With the introduction of direct vent gas stoves and fireplaces, and the flexibility to vent these appliances out a side wall, new exciting design options became available to the homeowner. Essentially, any room with an exterior wall is now a candidate for a direct vent gas stove or fireplace, including kitchens, baths and bedrooms.

Horizontal side-wall venting allows for other creative options, including fireplaces under stair landings and fireplaces in rooms where traditional vertical installations would not be feasible, such as rooms located under a living room or garage.

Horizontal side-wall venting also permits attractive designer installations, such as fireplaces installed under counter tops, bars, or positioned under wrap-around windows.

Direct Vent GS is also available in a full range of pipe lengths and accessories to complete a traditional vertical installation. Chimney liner kits are available for installing direct vent gas stove inserts into existing wood burning fireplaces.

Modern direct vent gas stoves and fireplaces feature thermostatic temperature control, with energy efficiency equal to or greater than your gas furnace. Enjoy the new realistic gas flames, complete with glowing embers, and the convenience at the push of a button on your remote control.
 
Direct Vent Fireplace

Offset
Figure 1

Minimum Chimney Clearance
Figure 2
Design & Selection of Direct Vent GS Venting System
The following design recommendations are intended as only a general guideline to assist in the design and selection of venting components for your installation. Read and follow the Direct Vent GS installation instructions before installing your venting system.
Important: Check the manufacturer's rating plate and instruction manual to confirm that the Simpson Dura-Vent direct vent system is approved for use on the brand name appliance you have selected.
The inner and outer pipe diameters should match the outlet size of the appliance.
Check the appliance manufacturer's installation instructions to confirm which types of vent configurations are permitted. (i.e. horizontal, vertical, chimney reline, etc.). Also, check for any venting restrictions such as maximum horizontal run, minimum and maximum vertical rise, maximum offset, etc.
Be fire-safe! Maintain the minimum clearances (air space) between the vent pipe and nearby combustibles, as specified in the appliance manufacturer's installation instructions. Use proper support and bracing. Follow local building codes and have your venting inspected.
HOW TO PLAN your venting installation:
STEP 1
For vertical gas stove installations, measure the height from the stove outlet to the ceiling to determine the length of black pipe required. Select a round or square support box. For a designer appearance, select decorative brass trim.
STEP 2
To determine the length of galvanized pipe required, measure the ceiling thickness, and the vertical rise in an attic or second story. Firestops are required at each floor level. If an offset is required to avoid obstructions, use a pair of 45° elbows. For proper support, use elbow straps with offsets. Use wall straps for long vertical runs.
STEP 3
Measure the roof pitch. Select the proper flashing and storm collar. Determine the minimum height above the roof.
STEP 4
For horizontal installations, check the appliance manufacturer's instructions for minimum rise and maximum horizontal run. A snorkel termination may be used if height restrictions prevent adequate rise above the appliance. Select standard or high wind square termination cap. To protect vinyl siding, select vinyl siding standoff. Check the appliance manufacturer's instructions for wall thimble and firestop requirements.
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