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For Hobbyists & Makers · HVAC Duct Designer

HVAC Duct Designer for a peak-demand day

Built for hobbyists & makers exploring it for fun. Play with real physics and math, no license and no setup — just open and tinker. Simulate a peak-demand day live below — adjust the inputs and watch it respond, right in your browser.

Fluid

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2D Fluid (CFD) StudioLive

Stam stable-fluids · Navier–Stokes

Controls

Speed1×

Click and drag on the canvas to inject dye and velocity.

Presets

Viscosity

Injection force

Dye amount

▶ Run in Python

Data Inspector

Grid96×96

Total dye0

Mean speed0.000

Max speed0.000

Enstrophy0.00e+0

Governing equation

\frac{\partial u}{\partial t} + (u \cdot \nabla) u = - \frac{\nabla p}{ρ} + 1.0 e - 7 \nabla^{2} u, \nabla \cdot u = 0

Reading this result: Near-zero viscosity: momentum barely dissipates, so vortices persist and the flow tips into turbulent, chaotic mixing.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Sound Levels

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Sound Levels (dB SPL)Live

adding & spreading loudness

Controls

Presets

Level per source at 1 m (dB)

Number of sources

Distance (m)

Decibels are logarithmic, so loudness does not add the way you expect: two identical sources are only 3 dB louder than one, and ten are 10 dB. Meanwhile a point source drops 6 dB every time the distance doubles (the inverse-square law). Sustained exposure above 85 dB risks hearing damage.

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Data Inspector

Combined at 1 m85.0 dB

At 4 m73.0 dB

Doubling sources+3 dB

Risksafe range

Governing equation

L = 85.0 - 20 lo g_{10} (4) = 73.0 dB

Reading this result: A single source falls from 85 dB to 73 dB across 4 m — about 6 dB lost each time the distance doubles.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Thermal Resistance

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Composite Wall Heat TransferLive

R-value & U-value

Controls

Presets

Drywall (mm)

Insulation (mm)

Brick (mm)

Inside temp (°C)

Outside temp (°C)

Heat flows through a wall like current through resistors in series. Each layer's thermal resistance is its thickness over its conductivity; adding them gives the total R-value, and the heat flux is the temperature difference divided by it. Insulation, with very low conductivity, dominates the R-value — the steep temperature drop shows where it does its work.

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Data Inspector

Total R-value2.71 m²K/W

U-value0.37 W/m²K

Heat flux9.6 W/m²

Governing equation

R = \sum \frac{L _{i}}{k _{i} A} = 2.71 \frac{m ^{2} K}{W}, Q = \frac{Δ T}{R} = 9.6 \frac{W}{m ^{2}}

Reading this result: The insulation layer carries the most thermal resistance, so the temperature falls most steeply across it. A total R-value of 2.71 m²K/W lets 9.6 W/m² flow for this 26°C difference.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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Frequently asked questions

Is this good for hobbyists & makers?: Yes — this version of "HVAC Duct Designer for a peak-demand day" is framed for hobbyists & makers exploring it for fun. Play with real physics and math, no license and no setup — just open and tinker.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.