advice for buying shop/home compressor?

When considering the purchase of a shop or home air compressor, it's important to keep various factors in mind to ensure you select the best model for your needs. A quick search on Google highlights the importance of knowing the compressor's capacity, its power requirements, and its suitability for your typical tasks. According to expert reviews, matching a compressor's specs with your tool requirements is essential for efficient operation.

Choosing the Right Compressor for Your Needs

After years of eyeing a Quincy model 210 pump, I finally found one brand new on Craigslist for just $100. Known as the Holy Grail of small compressor pumps—1 to 2 hp capacity and pressure lubricated—it met most of my needs. Though I hoped for a 310 pump, the 210 model without head unloaders or controls sufficed. To make it more functional, I bought unloader towers and a hydraulic unloader unit.

The Importance of Motor and Tank Specifications

Although the motor is only 1 hp, it's built on a 182T frame, comparable in size to a modern 5 hp motor. It pulls 18 amps at full load but stays barely warm, capable of running a 100% duty cycle. Paired with a 30-gallon tank, I found it offered ample burst capacity. However, for tasks that require large air volumes over an extended period—like sanding and grinding—a minimum of a 5 hp two-stage compressor is necessary.

Historical Context and Personal Experience

My father's 20-gallon, 1 hp Binks compressor, bought in 1967, powered his piano shop for years before undertaking various other projects. Despite needing minor repairs like valve springs and motor bearings, it continued working efficiently until the tank rusted out. I refurbished the pump and motor, installing them on a new 30-gallon stationary tank, which served me well for many years. This experience confirmed the reliability of well-built compressors.

Considerations for Dual Compressor Systems

Critique my plan to buy two air compressors rather than one.

Many sources may mislead you into thinking that CFM (cubic feet per minute) improves greatly as compressor output pressure decreases. This is only true if you're reducing the output pressure right as the air exits the compressor before reaching the storage tank. In reality, reducing the output pressure on a dual-stage compressor will not significantly improve its efficiency. Allowing the compressor to operate at its designed pressure, such as the IR compressor's 175 psi, results in better efficiency and greater CFM capacity. For instance, a large 104-gallon tank filled to 175 psi will provide more air at 90 psi for tools before needing a refill.

Note that many consumer-grade compressors operate at higher RPMs compared to commercial units, which makes them louder. If considering dual compressors, be prepared for increased noise. While older IR compressors are known for quality, I can't vouch for the current models personally.

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