Watts Aerco INN 1060N - Combustion Air Duct Pressure Drop Tables; Corrections for Altitude

Innovation Water Heaters – Edge [i] Controller
Venting and Combustion Air Design Guide
TAG-0090_A • GF-5056 • 2/20/2020 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 27 of 39
3.7. Combustion Air Duct Pressure Drop Tables
The tables in this section list the pressure drop in sealed combustion air ducts for the Innovation-
Edge models at various outside air temperatures and duct diameters.
3.7.1 Corrections For Altitude
The table below lists correction factors for installation altitudes above sea level. These factors
must be applied to both the natural draft and pressure drops of vent and air ducts. The pressure
drop through vents and combustion air ducts will increase at higher elevations, while the natural
draft will decrease.
Altitude Correction Table
Site Elevation Above
Sea Level
Altitude Correction Factor
(CF)
Feet
Meters
0
0
1
500
152.4
0.982
1000
304.8
0.964
1500
457.2
0.947
2000
609.6
0.930
2500
762.0
0.913
3000
914.4
0.896
3500
1066.8
0.880
4000
1219.2
0.864
4500
1371.6
0.848
5000
1524.0
0.832
5500
1676.4
0.817
6000
1828.8
0.801
6500
1981.2
0.787
7000
2133.6
0.772
7500
2286.0
0.758
8000
2438.4
0.743
8500
2590.8
0.729
9000
2743.2
0.715
9500
2895.6
0.701
10000
3048.0
0.688