system sizing

System SizingSystem Sizing

Proper System DesignProper System Design

•Load Calculation

•Equipment Selection

•Duct Layout

•Branch runs

•Terminations

•Start ups

•Customer checks

The Next StepThe Next Step

Kwik-WayKwik-Way

•Room By Room Load Calculation

www.spacepak.comContractor assistance

Load CalculationLoad 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 ExceptionsLoad Exceptions

•Sensible vs Latent•Don’t add 1/3rd for latent

•Sunrooms•Where does it face?

•Commercial applications•Exceptional heat sources?

Load CalculationLoad 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 WayKwik 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 toEquipment Selection

NEXT

•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

ALTITUDE CORRECTION

•determine atmospheric pressure at given altitude

Step One

Altitude Pressure = 14.696x(1-6.87535E-06xA)

5.2561

Where: A = altitude in feet

Step Two

•Correct CFM for AltitudeCorrected CFM =

529.67xaxb14.696x(c+459.6

7)Where: a=pressure at altitude, b=specific CFM, c=entering air temperature

ALTITUDE CORRECTION

ALTITUDE CORRECTION

Equipment SelectionEquipment SelectionEquipment SelectionEquipment Selection

•Check systems capacity chart

•Match to the load calculation

•Data on internet•www.ariprimenet.org

•Use mix match systems

ARI Listing (edited)ARI Listing (edited)

Model # SpacePak # Mfr SEER Matched capacity AEUAC024X1222 345719 ESP-2430V+TDRLUXAIRE, 11.10 * 22600 * $171*

AC024X1222 345540 ESP-2430D+TDRLUXAIRE, 10.90 * 22200 * $171*

System DesignSystem DesignLet’s do a house!

My Mother-In-Law’s house

My Mother-In-Law’s My Mother-In-Law’s househouse

• 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 Where do I fit the Equipment in ?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?Where to Place the Return?Central Location – Out of Direct Living AreaCentral Location – Out of Direct Living Area

Air Handler LocationAir Handler LocationAir Handler LocationAir Handler Location1. Return Air Duct Dictates Unit Location

• Best Location for Return Air Grill

• Split Return Air?

2. Unit Location Dictates Trunk Layout

• Best Option for Trunk Layout?

3. Outlet Location: Dictates Trunk Run

– How Many Outlets, Where do they go?

Air Handler LocationAir Handler LocationAir Handler LocationAir Handler Location

ESP-3642

Outlet LocationOutlet Location

ESP-3642

5190

4706

2385

606

3806

5935

2748

9910

• 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.

Outlet LocationOutlet Location

ESP-3642

5190

4706

2385

606

3806

5935

2748

9910

>

<

High Static PlenumHigh Static Plenum

ShortrunsShortruns Long runsLong runs

Will this pull

on fittin

g?

Considerations: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!!!!

SuggestedLayouts

Plenum ConnectionPlenum Connection

ESP-3642

5190

4706

2385

606

3806

5935

2748

9910

>

<

Estimating The JobEstimating 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 ConsiderationsAirflow Considerations

•Spacepak min. required outlets 14, 19, 26

•Split or extended return duct

•Filters

•New air handler, old system

We Never UndersizeWe 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