I have been using refrigeration compressors for many years as vacuum pumps.
When I started in commercial/industrial refrigeration some 30 years ago, all the engineers in "Prestcold" Bournemouth branch made their own small portable vacuum pumps from discarded domestic refrigerators. It almost appeared to me, a newcomer to the industry, a competition of sorts to make the most practical/aesthetic unit possible.Some engineers made varnished wooden cases to house the compressor. These were ideal for all small refrigeration vacuuming requirements.
My interest over the last few years has been to use these "home-made vac-pumps" to produce vacuum filled inverted aquaria. "The Romaurie-Effect" as shown on "youTube".This is an on-going project.