Combining Air Compressors To Increase Flow – Page Two. if you have just landed on this page, we are talking about getting more air flow to an air tool. If you care to review this article from the beginning, page one of Combining Air Compressors To Increase Flow is here.
If the ability of the compressor pump on a compressor is insufficient to keep up the air flow necessary for the air tool, and as discussed, adding another air tank will not solve the problem, another solution is combining air compressor to increase flow.
Add up the compressor CFM
The two compressors referred to by the original questioner can deliver 4 CFM at 90 PSI each. By combining the two compressors, the two could deliver a flow of 8 CFM at 90 PSI.
The real question is, is 8 CFM at 90 PSI sufficient flow for the application? The original poster says “My goal is to run a 10 CFM sand blast cabinet to its working potential.”
Sorry then, the answer is no. Combining the two 1.8 HP compressors can give a combined output of 8 CFM at 90 PSI, and if the sand blast cabinet needs 10 CFM at 90 PSI, these two air compressors, even if combined, will not provide enough air.
Compressor output is often theoretical?
Another issue that would concern me about combining these two compressors to try to get a higher flow is that the output from each, the 4 CFM at 90 PSI, is – at best – theoretical.
We are all familiar with the mileage estimates for our cars. If the car manufacturer tells us we’ll get 35 miles to the gallon on such and such a model, we’ll often nod sagely, and say to ourselves, “that means 25 MPG” in the real world.
It is the same for air compressors. What they claim you will get as output flow may be inflated, or theoretical only,l and may not actually be reproducible in the real world.
Expect to get less output than advertised to reduce making a bad decision about the right air compressor for the job.
240 Volt compressor supply?
The goal of the original poster is to get two compressors that, together, will give sufficient flow at 90 PSI for the 8 CFM required by the air tool. That is doable, but not with 1.8 HP compressors.
The rule of thumb is that a user should be able to get 2-4 CFM of air at 90 PSI for each HP of electric motor size.
Since the electric motor is converting electrical supply into compressed air, 120 Volts can only provide so much power to a compressor motor. If the pump is larger than a certain size, and in my books that’s about 2.5 HP, having 120 volts as the power supply to the compressor motor limits the output.
To get lots of air for the air tools, you need a bigger compressor pump. That means a bigger compressor motor to run that bigger pump. That means you need more available power to be converted into compressed air, and that means 240 Volts is the power supply of choice for a compressor to supply high demand air tools, not 120 VAC.
But I just need 8 CFM!
That being the case, sure, you can combine two air compressors to increase the flow. You just have to make sure that the two, combined, has the real flow necessary for the air tool. Here’s how to put two air compressors together.