©2006 Armstrong International, Inc. Basic Heat Transfer Concepts

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 2 Basic Heat Transfer Concepts And Their Relationships to Heating Coil Selection T Air T Steam T steam >>> T Air

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 3 Heat Transfer Only occurs when there is a temperature difference Flows faster when this difference is higher Always flows from high to low temperature Is greater with greater surface area Some materials transfer heat better than others

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 4 Heat Flows from High to Low T Air T Steam T steam >>> T Air

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 5 Thermal Conductivity of Common Coil Materials MaterialThermal Conductivity Copper2724 Aluminum1536 Steel314 Cupro-Nickle 90/10310 Cupro-Nickle 70/30200 Stainless Steel108

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 6 To Get More Heat Transfer From Bare Tubes... Add Fins to Increase Surface Area

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 7 Relative Heat Transfer: Identical Coils w/Different Tube Materials Tube MaterialRelative HT Capacity Copper1.00 Aluminum1.00 Steel0.98 Stainless Steel0.95

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 8 Relative Heat Transfer: Identical Coils w/Material Combinations* Tube MaterialFin Material Relative HT Capacity SteelCopper Keyfin1.05 SteelAluminum Keyfin1.00 Stainless SteelAluminum Keyfin0.94 SteelSteel L Fin0.92 Stainless SteelStainless Steel L Fin0.58 *At 800 FPM, 7FPI & 55 psig

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 9 Heat Transfer Equation Q = U x A x LMTD where Q = Heat Transfer Rate (BTU/hr) U = Heat Transfer Coefficient (BTU/hr/ft 2 / F) A = Surface Area (ft 2 ) LMTD = Log Mean Temperature Difference (b/w the Steam and the Air)

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 10 ©2002 Armstrong International, Inc. Assembly Concepts

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 11 Bare Tube Coils Heat Exchange = U x Surface Area x T Surface Area 1'' Pipe = 1 Sq Ft / Linear Ft

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 12 Extended Surface Coils Fin Area >>>>> Tube Area Tube is Irrelevant in Heat Transfer Fin Element Plate FinWound Fin

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 13 Coil Construction 1, 2, and 3 Row Coils Cond. Conn. Cond. Header Finned Tube Steam Header Steam Conn. 6 Tubes in the Face4 Tubes in the Face 7 FPI 1 Inch 4 FPI

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 14 Casings and Air Baffles Coil Casings Air Baffles Flanges Casing Depth Side Baffle Header Baffle Mounting Holes

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 15 Coil Casing Types Turned-Out Flange Standard Flange for Duct-Mounted Coils Turned-In Flange Used w/ Removable Coils or Where mounting holes are not needed & smooth casing face is wanted Dimensions & Spacing 7/16" 1-1/23/4

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 16 Removable (Drawer) Coils Core installed in a casing w/ flanges on 3 sides and a mounting place on the 4 th side Coil slides into outer casing like a drawer Bolt Holes Lifting LugMounting Plate

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 17 Coil Configuration Air Inlet Air Outlet Steam Horizontal Air Flow Horizontal Tubes Vertical Tubes Condensate

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 18 Coil Configuration Vertical Up Air Flow Horizontal Tubes Vertical Down Air Flow Horizontal Tubes Air Inlet Side Air Outlet Side Air Inlet Side

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 19 Parallel Multiple Coils

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 20 Series Multiple Coils Steam Supply End Air Flow Condensate Return End

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 21 4 Coils in Parallel x 3 Coils in Series 12 Coils Total Drain each coil separately 12 Traps may discharge to common Header Multiple Coil Installation Common steam supply OK

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 22 Heavy Duty Construction Min Thick Fins on 12 Ga. CS Thick Tubes 12 Ga. Casing and Baffles Sch 80 Connections Sch 40 Headers 250 psig Standard Pressure Rating

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 23 Heavy Duty Construction Header, Connections & Tubes (wetted parts) Same Material No Galvanic Corrosion All Joints Welded No Leaks Thicker Materials Fights Corrosion

Model Number Selection

Extended Surface (Fin Tube) Heating Coils

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 26 Which Fin Type? Standard KeyFin Tight joint over wide temperature range Best for dissimilar tube and fin materials

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 27 Which Fin Type? L-Fin L-shaped foot tension wound over knurled tube Best for same material tubes & fins Large contact area for high heat transfer Some corrosion protection for tube

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 28 Tube Materials Carbon Steel Affords both strength & corrosion resistance Standard12 Ga A-214 ERW (1 or 1½ OD) Optional10 Ga A-214 ERW 10 Ga or 12 Ga A-179 Seamless Stainless Steel (304L or 316L) When corrosive steam is present or when ideal piping & trapping practices cannot be followed 14 Ga (1 OD) & 12 Ga (1½ OD)

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 29 Fin Materials Steel Fins stand up against aggressive cleaning Thick on 1 OD or 1 1/2 OD Tubes Thick on 1 ½ OD Tubes Aluminum Fins provide the best overall value Thick Keyfin on all Tube Sizes Thick Keyfin on all Tube Sizes Stainless Steel Fins fight high external corrosion Thick Type 304L & 316L on 1 OD Tubes Copper Fins provide the best heat transfer Thick on All Tube Sizes

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 30 Conns/Headers/CasingConns/Headers/Casing Headers Same Material As Tubes With Welded Construction Connections Steel: Sch 80 (screwed) or Sch 40 (flanged) Stainless Steel: Sch 40 (screwed) or Sch 10 (flanged) Casing 12 Ga. Galvanized Steel or 12 Ga Stainless Steel

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 31 Coil Type Standard (Type S) Centifeed (Type C) Tendam (Type T) Centifeed Tandem (Type P)

Type S coils are available with opposite-end connections only Type C coils are available with same-end connections only AIR FLOW

2-Row Standard Coil2-Row Centifeed Coil AIR FLOW

Type T coils have opposite-end connections Type P coils have same-end connections AIR FLOW

Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ® 35 Armstrong Promise We provide intelligent system solutions that improve utility performance, lower energy consumption, and reduce environmental emissions... while providing an enjoyable experience! 35 Expect many enjoyable experiences! David M. Armstrong Expect many enjoyable experiences! David M. Armstrong ®

Expect many enjoyable experiences! David M. Armstrong