1. 1 Trade Skills HVACR116 Sheet Metal

2. 2 The most common types of duct material are: –Aluminum –Fiberglass duct board –Spiral metal duct –Flexible duct All of these types of materials have been used successfully The most common types of duct material are: –Aluminum –Fiberglass duct board –Spiral metal duct –Flexible duct All of these types of materials have been used successfully

3. 3 Sheet Metal (cont.) The first type of metal going to be discussed is Galvanized-Steel Duct This particular metal is treated with a zinc coating to keep the steel underneath from corroding. Galvanized sheet metal comes in different thicknesses that are known as gauge. The first type of metal going to be discussed is Galvanized-Steel Duct This particular metal is treated with a zinc coating to keep the steel underneath from corroding. Galvanized sheet metal comes in different thicknesses that are known as gauge.

4. 4 Galvanized-steel Duct As the gauge number gets larger, the thickness of the sheet metal gets thinner. Ex. 30-ga galvanized sheet metal is 0.0157 inches thick, while 22-ga galvanized sheet metal is 0.0336 inches thick. Notice that the 22-ga metal is about twice as thick as the 30-ga As the gauge number gets larger, the thickness of the sheet metal gets thinner. Ex. 30-ga galvanized sheet metal is 0.0157 inches thick, while 22-ga galvanized sheet metal is 0.0336 inches thick. Notice that the 22-ga metal is about twice as thick as the 30-ga

5. 5 Sheet Metal (cont.)

6. 6 Sheet Metal Sheet metal thickness is directky related to its weight. The Standard Gauge for Sheet Metal is 41.82 lb/ft2. This is a common factor, when multiplied by the thickness of the metal. You will get the weight of one square foot of the metal. Sheet metal thickness is directky related to its weight. The Standard Gauge for Sheet Metal is 41.82 lb/ft2. This is a common factor, when multiplied by the thickness of the metal. You will get the weight of one square foot of the metal.

7. 7 Ex. The thickness of 24-ga metal is 0.0239 in. Ex. The weight of 1 ft2 of this material is 1 lb lb=(0.0239 inches x 41.82 lb/ft2) Lb=.99 or 1 Ex. The thickness of 24-ga metal is 0.0239 in. Ex. The weight of 1 ft2 of this material is 1 lb lb=(0.0239 inches x 41.82 lb/ft2) Lb=.99 or 1

8. 8 Sheet Metal (cont.) Ex. Lb=(0.012 inches x 41.82 lb/ft2) Ex. Lb= Ex. Lb=(0.012 inches x 41.82 lb/ft2) Ex. Lb=

9. 9 Fiberglass Duct Fiberglass duct is also known as Duct Board. Fiberglass duct comes in 2 different styles –Flat sheets –Round prefabricated duct Fiberglass duct is also known as Duct Board. Fiberglass duct comes in 2 different styles –Flat sheets –Round prefabricated duct

10. 10 Fiberglass Duct (cont.) Fiberglass Duct Flat Sheets

11. 11 Fiberglass Duct (cont.)

12. 12 Fiberglass Duct (cont.)

13. 13 Fiberglass Duct (cont.) Round Prefabricated duct

14. 14 Spiral Metal Duct Spiral duct is used on large sytems. The duct is formed from flat metal and has seams all the way down the duct. It comes in 10’ lengths Spiral duct is used on large sytems. The duct is formed from flat metal and has seams all the way down the duct. It comes in 10’ lengths

15. 15 Spiral Metal Duct (cont.)

16. 16 Spiral Metal Duct (cont.)

17. 17 Flexible Duct Flexible duct also known as Flex, comes in sizes up to 24 inches in diameter. Some of flexible duct comes with or without insulation. Flexible duct comes in 25’ lengths. Code only allows us to run a maximum of 14’ per run out. Flexible duct also known as Flex, comes in sizes up to 24 inches in diameter. Some of flexible duct comes with or without insulation. Flexible duct comes in 25’ lengths. Code only allows us to run a maximum of 14’ per run out.

18. 18 Flexible Duct (cont.) Uninsulated

19. 19 Flexible Duct (cont.) Insulated

20. 20 Flexible Duct (cont.)