[londons_explore]

Air compressors need not be noisy.

Your fridge at home likely has a cylinder air compressor in it, pumping gas up to 30 bar (400 psi) and it only makes a quiet humming.

The trick is that air compressor is attached to a big vibration damping weight, mounted on big springs, which are mounted into an oil filled heavy steel box, which is itself mounted onto rubber feet.

[mnouquet]

> The trick is that air compressor is attached to a big vibration damping weight, mounted on big springs, which are mounted into an oil filled heavy steel box, which is itself mounted onto rubber feet

So easy... If it was that easy, it would have already been done, but...

1) compressor are maybe 100lb of solid cast steel

2) owners need to fix mechanical wear, not simply "replace the whole thing" - head gasket fails, gauges fails, hose leak (think thermal expansion / contraction), oil need to be changed, etc.

3) refrigerator system are sealed, air compressor need to pull air from the outside (ie. it can be DIRTY), which means lot of the noise actually come from the intake

[lttlrck]

Isn't the difference that a refrigerator is a closed system whereas many industrial/workshop air compressors are open and must maintain relatively high pressure due to a "controlled leak"? I am certainly no expert but they don't seem the same to me?

[londons_explore]

Cut a pipe on the back of a fridge and it'll run open circuit just fine. Doesn't make it appreciably louder. (beware, some fridge gasses are illegal to vent to the atmosphere, and others are pretty explosive)

[mnouquet]

> Cut a pipe on the back of a fridge and it'll run open circuit just fine

Try to run a plasma cutter, or a 1" impact wrench out of a fridge compressor...

[londons_explore]

Those things also don't need 400psi.

A modified fridge compressor could have 4x the capacity at 100psi and be suitable for a small workshop.

[mnouquet]

Do you understand the concept of air flow at a specific pressure ? 15CFM at 90psi is no small feat.

Lowering working pressure does not increase CFM, pump have a fixed displacement at their most efficient RPM, it's not gonna change...

[mnouquet]

The CFM rating of a fridge is nowhere close to the CFM requirement of industrial processes.

[ohazi]

Scroll compressors are also known for being relatively quiet.