System Sizing
Proper System Design • Load Calculation • Equipment Selection • Duct Layout • Branch runs • Terminations • Start ups • Customer checks
The Next Step • Room By Room Load Calculation Kwik-Way www.spacepak.com Contractor assistance
Load Calculation • Essential for a properly performing job • Shortcuts are not encouraged • BTUs not CFM!!! • Loads give you net values • Equipment discussed in nominal values
Load Exceptions • Sensible vs Latent • Don’t add 1/3rd for latent • Sunrooms • Where does it face? • Commercial applications • Exceptional heat sources?
Load Calculation • ACCA Manual J • Industry Standard • Currently revision 8 • Not for commercial loads • Cautions in rooms with large glass areas • Use peak function for large glass areas • www.acca.org
Kwik Way • Runs from Internet • www.spacepak.com and then contractor assistance • http://www.spacepak.com/html/hvac_contractor_installation.htm • Quick program • Free • Does not keep files, must print out Skip to Equipment Selection
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This was done off internet…. • www.spacepak.com • Room by room analysis. • Totals load and suggests model and size. • Nice presentation tool. • Want a CD? Ask you salesmen….
ALTITUDE CORRECTION Step One • determine atmospheric pressure at given altitude 5.2561 Altitude Pressure = 14.696x(1-6.87535E-06xA) Where: A = altitude in feet
529.67xaxb Corrected CFM = 14.696x(c+459.67) ALTITUDE CORRECTION Step Two • Correct CFM for Altitude Where: a=pressure at altitude, b=specific CFM, c=entering air temperature
Equipment Selection • Check systems capacity chart • Match to the load calculation • Data on internet • www.ariprimenet.org • Use mix match systems
ARI Listing (edited) Model # SpacePak # Mfr SEER Matched capacity AEU AC024X1222 345719 ESP-2430V+TDRLUXAIRE, 11.10 * 22600 * $171* AC024X1222 345540 ESP-2430D+TDRLUXAIRE, 10.90 * 22200 * $171*
System Design Let’s do a house!
My Mother-In-Law’s house
My Mother-In-Law’s house • 80’s Ranch. • On a slab • Attic space available • Windows are double pane, low “e” • Walls are R13 • Ceilings are 8’ R19 • Heated with boiler and baseboard (cooling only) • 70 by 38 ft.
This was done on internet…. • www.spacepak.com • Room by room analysis. • Totals load and suggests model and size. • Nice presentation tool. • Want a CD? Ask your salesmen….
Where do I fit the Equipment in ? • Look for a central return grill spot • Horizontal or Vertical Unit • Spacepak in the attic or basement • Reaching the other floors w/ 2” • “I want the condenser behind the garage” • Commercial and multi-zone systems
Where to Place the Return? Central Location – Out of Direct Living Area
Air Handler Location • Return Air Duct Dictates Unit Location • Best Location for Return Air Grill • Split Return Air? • Unit Location Dictates Trunk Layout • Best Option for Trunk Layout? • Outlet Location: Dictates Trunk Run • How Many Outlets, Where do they go?
Air Handler Location ESP-3642
ESP-3642 Outlet Location 5190 606 3806 2748 4706 9910 2385 5935
Restrictors and Balancing: Each 2”run will provide between 1700-2000 btu at a run length of 10’-20’ 3 restrictor sizes 15%, 30% and 50% Living room = 3 full runs Family room = 5 full runs How about the Dining room? Needs two outlets but gain is only 2800 btu. Use 2 30% restrictors on both runs. = 2800 btu Runs must total 19 full open for 3642D – 850 CFM to get ESP to 1” and 1.5” W.C.
5190 606 > < 3806 2748 ESP-3642 4706 9910 2385 5935 Outlet Location
High Static Plenum Will this pull on fitting? Short runs Long runs
Considerations: • Want to keep runs as close as possible to 10 feet in length. Full 40 cfm and 2000 btu per outlet makes it much easier to balance….. • Generally less $$$ to run supply plenum extra distance than run long 2” runs. • Want to “premake” the 2” runs downstairs where it’s nice and cool!!!!
Suggested Layouts
5190 606 > < 3806 2748 ESP-3642 4706 9910 2385 5935 Plenum Connection
Estimating The Job • Good measurements can make you money • Old homes are gold but full of surprises • Refer to Spacepak’s Typical equipment list • Two sizes fit all • Spacepak is a premium product • Selling the extras
Airflow Considerations • Spacepak min. required outlets 14, 19, 26 • Split or extended return duct • Filters • New air handler, old system
Conventional systems undersize for humidity removal Difficult to keep up on 100° days Space Pak’s 6 row coil Humidity control built in Size for the worst day We Never Undersize
