You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
2-stage compressors
- Thread starter ed_v
- Start date
2-stage units will provide higher CFM at higher pressures than single-stage units. Intake air first goes to a high volume cylinder, is compressed and then passed to a smaller, high pressure cylinder. The high pressure cylinder then pushes the air into the tank while the low pressure cylinder(s) are drawing in more air.
My 4 cylinder unit has 3 low pressure cylinders and one high pressure cylinder.
My 4 cylinder unit has 3 low pressure cylinders and one high pressure cylinder.
Franz©
Banned
Single stage is preferred where a high volume of compressed air is used at a pressure below 100psi. That's their efficiency sweet spot. Above 100 psi the piston size works against efficiency.
2 stage machines gain efficiency by taking the delivery of the low pressure side and recompressing it to a higher pressure. The tradeoff is that a 2 stage compressor delivers less cfm for the same input horsepower.
Compressed air is the most expensive form of energy you can employ on tools, but it offers a lot of advantages in certain work environments, and you can blow tires and basketballs up with it.
Energy input to compress air isn't linear. It takes the same volume of energy to compress air into a closed reservoir from 100 psi to 150 psi that it took to get the air from 1 atmousphere to 100psi, with a 2 stage machine. If you go from 100psi to 150psi with a single stage machine it will take roughly twice the energy the 2 stage required. Getting from 150 to 175 psi requires the same energy on a 2 stage as was required to get from 1 atmousphere to 100psi. 175psi compressed air is pretty much a waste of energy unless there is a specific requirement for that pressure.
Intercoolers do NOT lower temperature sufficiently between compressor jusg to dropmoisture since the air is way above dew point at that stage of the compression. Intercoolers do provide enough cooling to increase efficiency in the secondary jug.
2 stage machines gain efficiency by taking the delivery of the low pressure side and recompressing it to a higher pressure. The tradeoff is that a 2 stage compressor delivers less cfm for the same input horsepower.
Compressed air is the most expensive form of energy you can employ on tools, but it offers a lot of advantages in certain work environments, and you can blow tires and basketballs up with it.
Energy input to compress air isn't linear. It takes the same volume of energy to compress air into a closed reservoir from 100 psi to 150 psi that it took to get the air from 1 atmousphere to 100psi, with a 2 stage machine. If you go from 100psi to 150psi with a single stage machine it will take roughly twice the energy the 2 stage required. Getting from 150 to 175 psi requires the same energy on a 2 stage as was required to get from 1 atmousphere to 100psi. 175psi compressed air is pretty much a waste of energy unless there is a specific requirement for that pressure.
Intercoolers do NOT lower temperature sufficiently between compressor jusg to dropmoisture since the air is way above dew point at that stage of the compression. Intercoolers do provide enough cooling to increase efficiency in the secondary jug.
Major Ramifications
Well-known member
Also, the two stage units are usually built to more commercial-use standards, usually with better lubrication and filtering. Generally speaking the pumps run more slowly, so they should last longer, and run more quietly.
If a single stage unit will do everything you will ever need it to (mine does), then a two stage is just a luxury. Of course, if money were no object, I would have a two stage. Oh hell, if money were no object I'd have a screw compressor or something like that.
I guess what I am saying is, figure out how you will use it now and in the future, and go from there.
If a single stage unit will do everything you will ever need it to (mine does), then a two stage is just a luxury. Of course, if money were no object, I would have a two stage. Oh hell, if money were no object I'd have a screw compressor or something like that.
I guess what I am saying is, figure out how you will use it now and in the future, and go from there.
Charlie's68
Well-known member
- Joined
- Mar 28, 2007
- Messages
- 95
Single stage is preferred where a high volume of compressed air is used at a pressure below 100psi. That's their efficiency sweet spot. Above 100 psi the piston size works against efficiency.
2 stage machines gain efficiency by taking the delivery of the low pressure side and recompressing it to a higher pressure. The tradeoff is that a 2 stage compressor delivers less cfm for the same input horsepower.
Compressed air is the most expensive form of energy you can employ on tools, but it offers a lot of advantages in certain work environments, and you can blow tires and basketballs up with it.
Energy input to compress air isn't linear. It takes the same volume of energy to compress air into a closed reservoir from 100 psi to 150 psi that it took to get the air from 1 atmousphere to 100psi, with a 2 stage machine. If you go from 100psi to 150psi with a single stage machine it will take roughly twice the energy the 2 stage required. Getting from 150 to 175 psi requires the same energy on a 2 stage as was required to get from 1 atmousphere to 100psi. 175psi compressed air is pretty much a waste of energy unless there is a specific requirement for that pressure.
Intercoolers do NOT lower temperature sufficiently between compressor jusg to dropmoisture since the air is way above dew point at that stage of the compression. Intercoolers do provide enough cooling to increase efficiency in the secondary jug.
so your saying, if you were running basic air tools, that didnt require 175psi specifically, that you would lower the rating to 150psi? what would be the downside here?