HS-ETS1-2 Engineering Design

Puerto Rico Vaccine Cooler Design Lab

A mobile clinic is delivering vaccines after a hurricane-triggered grid outage. Your job is to keep the cooler between 2°C and 8°C for 72 hours by breaking the larger cold-chain problem into smaller engineering problems, comparing subsystem options, and justifying your tradeoffs.

Budget cap

$4,500

Mass cap

65 kg

Target window

2-8°C

Context

Storm outage

1. Break the problem apart

Select at least two sub-problems, decide what to test first, and commit to a priority before the mission run is unlocked.

Inquiry first

Sub-problems to solve

Slow down heat entering the cooler Improve insulation and reduce solar heating so the compressor spends less energy. Store or generate enough cooling energy Balance PCM packs, battery capacity, and solar charging across 72 hours. Limit warm-air spikes during vaccine pickup Reduce how much heat rushes in each time staff access doses. Keep the design portable and affordable Mass and cost matter because the clinic is moving supplies across damaged roads.

Solve first

Highest-priority criterion

Prediction before testing

Insulation will drive the biggest improvement. Cooling power and storage will matter most. Access workflow will be the deciding factor.

2. Configure the field conditions

Clinic pickups per day 18

More pickups mean more lid events and more warm-air intrusion.

Storm severity 1.00x

Higher severity means darker storm skies, tougher road conditions, and a hotter, more unstable field environment.

3. Assemble a design

Insulation package

Cooling and power kit

Dose access workflow

4. Compare one subsystem with evidence

Required by HS-ETS1-2

Use the same storm conditions to compare multiple solutions for one sub-problem before making your final decision.

Complete the problem-decomposition choices above to unlock a scored mission run.

Safe hours

--/ 72

Peak temp

--°C

Min battery

--%

Total cost

$--

Total mass

--kg

Design score

--/ 100

Storm scene and cooler model

The canvas links the field conditions to the cooler state: hotter air, more openings, and weaker charging all change the thermal balance.

Preview model ready

Current module balance

Choose modules to see how the system fits together.

Priority tradeoff

Pick a highest-priority criterion to explain your tradeoffs.

Prediction check

Make a prediction before you run the scored mission.

72-hour data traces

Track how internal temperature and battery charge change across the outage.

Quantitative evidence

Subsystem comparison

Use the same scenario to compare multiple solutions for one sub-problem.

No comparison yet

Evidence-based design rationale

Select your decomposition choices and compare a subsystem to generate an evidence-based explanation of how the smaller solutions connect back to the larger cold-chain problem.

Mission log

Record each full run so you can analyze patterns across trials.

0 trials

Trial	Priority	Subsystem tested first	Safe hrs	Peak temp	Cost	Mass	Score

Why this phenomenon fits HS-ETS1-2

This design challenge is complex because the mobile clinic must solve several connected problems at the same time: slowing heat gain, storing or generating cooling energy, reducing access losses, and staying portable enough for damaged roads. Students use scientific evidence from temperature traces and subsystem comparisons to justify how smaller engineering decisions fit together into one larger cold-chain solution.