2b0e27d975c5b1ac1afbe4b1246f65e4.ppt
- Количество слайдов: 39
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 1/3 rd 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_install ation. 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. 696 x(1 -6. 87535 E-06 x. A) Where: A = altitude in feet
ALTITUDE CORRECTION Step Two • Correct CFM for Altitude 529. 67 xaxb Corrected CFM = 14. 696 x(c+459. 67) 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 # Space. Pak # Mfr SEER Matched capacity AEU AC 024 X 1222 345719 ESP-2430 V+TDRLUXAIRE, 11. 10 * 22600 * $171* AC 024 X 1222 345540 ESP-2430 D+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 R 13 Ceilings are 8’ R 19 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 1. Return Air Duct Dictates Unit Location • • 2. Best Location for Return Air Grill Split Return Air? Unit Location Dictates Trunk Layout • 3. Best Option for Trunk Layout? Outlet Location: Dictates Trunk Run – How Many Outlets, Where do they go?
Air Handler Location ESP-3642
Outlet Location 5190 606 3806 ESP-3642 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 3642 D – 850 CFM to get ESP to 1” and 1. 5” W. C.
Outlet Location 5190 606 > 3806 ESP-3642 < 2748 4706 9910 2385 5935
High Static Plenum Short runs l ul s p g? hi in ll t fitt i W n o 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
Plenum Connection 5190 606 > 3806 ESP-3642 < 2748 4706 9910 2385 5935
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
We Never Undersize • • 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