Isolated Air Conditioning SystemTaylor Bontz

Josiah Bujanda

Christopher Hubbard

Adam Mengestab

Edgar Vazquez

Faculty Advisor: Dr. Yong X TaoIndustry Sponsor: Peterbilt

Abstract/Objective

Total fuel used by idling trucks: estimated at over 2 billion gallons/year Currently 3.5 million truckers on the road

Each requiring 10 hours of rest per day.

To regulate comfort, drivers currently have limited options Leave the truck on all night

Deal with the intense heat/cold

Rising costs in fuel, as well as the emphasis on green energy Our solution:

Create a canopy system that dramatically reduces the overall area that a truck’s AC has to cool.

Quicken cooling times while also entrapping cool air

Inspiration Our approach:

Inspired by the capsule hotel designs; very popular in countries like Japan

Containing cool air while also improving the overall sleeping experience, without interfering with the original functionality of the sleeper.

Identical wall dimensions A retractable, portable hotel experience

CAD Drawing

Old Design New Design

Old design problems:- 2nd layer tarp difficult to keep rigid- Rail system expensive- Skeleton structure material expensive

Materials

Hollow 6061 aluminum rods for the skeleton Rigid, strong material (yield strength 55 Mpa)

Light weight (1/16” hollow rods, 1lb./ft.)

Inexpensive

½” Thick, insulated tarp Outer cover: 12 mm poly

½” cell foam insolation

R value: 3.25

K value: .003908

Lightweight (8 lbs.)

Total weight of material (minus bolts and screws)

32 pounds

Skeleton 3 hollow square rods

Minimize weight while allowing appropriate level of strength and support

Metal attaching rods to hold tarp shape

Simple door hinge attachments Allow top skeleton system to lift vertically

Allows lower skeleton system to bend inward & out of the way

Structure should not interfere with television, lifting bed or any doors.

Struts Two struts add 24 lbs. of lift each The tarp friction of the bed prevents complete lift, but keeps the skeleton stable

and provides ease of use.

Magnets Also for ease of use, a series of Neodymium mountable magnets were installedMaterial: NdFeB, Grade N42

Plating/Coating: Ni-Cu-Ni (Nickel)

Magnetization Direction: Thru Thickness

Weight: 0.63 oz. (17.92 g)

Pull Force: 26.75 lbs

Brmax: 13,200 Gauss

BHmax: 42 MGOe

Ensures upper skeleton snaps into place Eases transition to close skeleton (left) Mounted magnets (right) snap skeleton into place

Canopy

Velcro We lined the skeleton and inside of the tarp with Velcro for easy removal For safety reasons, the canopy was not allowed to interfere with the

functionality of the bed safety netting. The easy removability of the tarp will ensure no interference with the netting,

or any other safety features inside the sleeper.

HVAC Design

HVAC Design

Used a window A/C unit Cooling Capacity: 3516 W (12000 Btu/hr) Cooling Load Approx 500 W

Peterbilt has a 700 W A/C unitavailable for use.

Exit Air Temp: 16°C Air Speed: 4.5 m/s at vent Volumetric Flow Rate: 0.2757 m3/s

HVAC Design

Energy Analysis

The amount of energy required to cool air can by calculated by

80% difference

Energy Analysis

The sum of the loads when multiplied by timecan be used to replace the total energy used tocause an updated change in temperature

P represents the cooling load (1758 W) assuming constant load

q represents the heat rate through the tarpand is calculated using the instantaneoustemperatures and the properties of the tarpby using the Equivalent Resistance Method

Energy Analysis

The equations can be rearranged to solve for instantaneous inside temperature

Works in ideal conditions

Testing

Temperature dropped at a significantly slower rate than in ideal situation The practical drop from 23.5 C to 19 C took approximately 13 minutes

vs the 3 minute theoretical drop

Primary reason is escaped cool air.

Theoretically, the percent difference is still significant if not the same when losses are considered.

Thermal Data Phase 1

Thermal Data Phase 2

Why Automation?

Provides functionality and flexibility Real time monitoring system, data analysis Improve comfort levels while reducing energy loads Cost effective Create a database of information, for processing, analyzing, and improving Ease of use and high level of compatibility with existing infrastructure

Control SystemThe control system is based off of open source technologies and user generated content, this provides a high level flexibility and adaptation

Raspberry Pi: Micro computer with micro controller inputs and outputsControls Relays through low voltage output, 5V coil activation

Mechanical Relays: 8 Channel 10A 250VAC relaysSwitch a variety of loads, with built in circuit protection, and

notification systemCustom Webserver: Secure, versatile, and can be modified to suit need

The webserver handles data requests and can be used for scheduling, monitoring, and future additionsQuick to deployCost EffectiveUses existing technologies and infrastructure

Control SystemThe control system is based off of open source technologies and user generated content, this provides a high level flexibility and adaptation

Intuitive User interface: Provides familiar touchscreen functionality

Ease of use was of key importance.

Unlimited Connectivity: Any device capable of running Javascript can be a host device

Smartphones, tablets, laptops, no internet connection required, LAN functionality

Extremly low power consumption: 22 Watts at peak power

Remotely Accessible/Field Adjustable: Allows for user customization remotely

The system can be accessed and monitored from any locationConstantly updating softwareSelf diagnosing error correction

Expandability Rapid Cooling

Scheduled persistent cooling Sustained temperature control

Hysteresis to maintain efficiency and control Reducing Comfort Priority

Based on user activity Reduce cooling load to save power Monitor Sleep patterns to assess comfort level

Can be coupled with existing API to develop new ways of approaching efficiency

Increase cooling load before user wakes up Provides added comfort when user is aware

Expenses ADA Fruit Kit System

Wireless Keyboard/Mouse combo $29.95 Temperature/Humidity Sensor $15.00 5V 2A switching power supply $7.95 HDMI Cable $3.95 Miniature Wifi Module $11.95 HDMI 4 Pi: 7” Display & Audio $99.95 Raspberry Pi 2 Ultimate Starter Kit $99.95

Skeleton/Tarp System 30’ Velcro tape $33.94 1/16”x8’ Aluminum rod (3) $27.78 Aluminum rod Stiffener $9.26 Canopy support rods (3) $18.81 Hinges (6) $29.78 Nuts, bolts and screws (est) $35.00 Neodymium Magnets (5) $26.20

Total Raspberry Pi Kit: $268.70 Total with HDMI Pi Display and Hardware: $449.47 Total without HDMI Pi Display +Hardware: $349.52 Total Hardware/Skeleton Only: $180.77

Future Opportunities for Improvements

Remove air leakage (utilize bulb seal)Make skeleton out of molded plastic (lighter)More testing (with a live sleeper)New material for the frame (custom molded for

manufacturing) Improve strut strengthTest Raspberry Pi with an actual Peterbilt AC

unit