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Arbor Scientific Hot Water Stirling Engine

Hot Water Stirling Engine

Item #96-7110
$45.00 Bundle Discount

Turn a cup of hot water into a working heat engine

The Hot Water Stirling Engine is a tabletop thermodynamic model that runs on nothing more than the temperature difference between a cup of hot water and the cooler air above it. Place the engine on a mug of hot water, give the flywheel a gentle push, and students watch a real heat engine convert thermal energy into continuous mechanical motion — no fuel, no batteries, no flames.

Why Teachers Love It

  • Runs on Classroom-Safe Hot Water – No open flames, no alcohol burner, no pressurized steam. Hot tap water or coffee is all it takes, making this safe and practical for demos at any grade level.
  • Visible Piston Motion Teaches the Cycle – The transparent chamber lets students observe the displacer piston as it moves through compression and expansion, connecting the physical mechanism to the thermodynamic P–V diagram.
  • Temperature Difference Is the Variable – As the water cools, the engine slows, giving students a live demonstration that engine output depends directly on the temperature gradient, which is a core concept of thermodynamics and the Carnot limit.
Resources
Product Details

What You Can Teach with the Hot Water Stirling Engine

Grades 6–8 (Middle School)

  • Energy transformation: thermal energy converted to mechanical energy
  • Heat flows from hot to cold — and that flow can do work
  • Observing the effect of temperature difference on engine speed
  • Introduction to external combustion engines and real-world energy systems

High School Physics / Chemistry

  • The four stages of the Stirling thermodynamic cycle (isothermal expansion, isovolumetric cooling, isothermal compression, isovolumetric heating)
  • Pressure–volume (P–V) diagrams and what they represent physically
  • First and second laws of thermodynamics demonstrated in a working system
  • Carnot efficiency and why no heat engine can be 100% efficient
  • Relating engine RPM to temperature difference for quantitative analysis

AP Physics / Engineering / STEM Electives

  • Calculating thermal efficiency from hot and cold reservoir temperatures
  • Experimental investigation: measure rotational frequency vs. ΔT
  • Comparing ideal Stirling cycle efficiency to observed engine performance
  • Energy conversion chains in real-world power generation

Products being sold are not toys. They are for Educational / Laboratory use only. They are not for use by children 12 and under.

Product Specifications

Specs:

Heat source: Hot water (approximately 50°C or higher — hot tap water, tea, or coffee)

No fuel, batteries, or open flame required

Transparent quartz cylinder: allows direct observation of displacer piston motion

Materials: Aluminum alloy base and components; quartz glass cylinder

Operation: Place engine on hot water surface; give flywheel a gentle push to start

Engine type: Low-temperature differential (LTD) Stirling engine

Base Diameter: 3.75"

Height: 4"

FAQ
No specifications available.
Warning: California Residents

WARNING: Cancer & Reproductive Harm — www.P65Warnings.ca.gov

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