01/18/2020
This week I quoted a job to fix a new install done by a company from out of town and I wanted to share some things that I have found are usually a warning sign.
This one had the local company measure out the floor space in the compressor room, not one person showed up to physically look at the compressor room or the facility where the air was used. No consideration was given to the actual demand and how changes to the system would affect demand. It was this is our "standard system" we install at all these locations.
In over thirty years of working on air compressors as a mechanic I will tell you this,,, there is no such thing as a "standard system" in a facility like this. Most locations have a unique set up when you consider sight conditions, environmental conditions, ventilation and temperature and humidity swings between seasons just to name a few. If the people selling it are only concerned with the size of the box that the box they are going to sell you can fit in it.... chances are it won't work as intended.
That is the case here with this facility, the old compressor system had a twin tower pressure swing regenerative air dryer, it was replaced with a cycling type refrigerant air dryer. And I know most people would say its a dryer whats the problem? Two things,,,
First is the pressure dew point, this how we measure the amount of moisture in compressed air systems. Sometimes painters will call it relative humidity but its pretty close to the same thing. The old air dryer produced a pressure dew point of about -40 degrees F. and that means the air temperature would have to drop to below that point for any more moisture to drop out of it,,,, essentially VERY dry air. The new air dryer produces a pressure dew point of +40 degrees F. Still dry air, just not near as dry as before. I have plenty of body shops that still paint cars with air of this quality but I hope you see there is a difference.
Secondly is the original air dryer used a portion of the compressed air to operate, that number is a calculated guess of 50 cfm and I am sure an engineer somewhere will argue these numbers if he knew all the data...... So now the system demand has dropped by approximately 25% of the air compressors capacity but they are installing the same size machine in a goal to save money.....
To make matter worse they installed a frequency drive or VSD drive air compressor because this is the magic bullet company's love to sell as a fix all. Now don't take me wrong, installed and sized correctly these machines can save you a lot on your electrical bill every month..... the key word here is "Sized CORRECTLY" This application given the current demand on the system they would have made out far better with a thirty hp compressor of this type instead of wasting money on a fifty hp compressor that is now considerably oversized, doesn't work as it should and will require more storage capacity to get the controls to remotely work correctly and have the possibility of saving even the higher initial cost of this machine vs a standard machine.
If they won't even walk in the door to sell you an air compressor.....stop there,,,, and call someone who would at least put the key in the ignition to see what your specific needs are.
Morris Machine Services LLC is your source for quality Air Compressor Sales and Service. Authorized
