By Ricardo Pires


Tier 4 compressors – why they might be the best choice

When we talk about tiers in compressors, we are referring to their engines and to the processes that are used to guarantee a certain maximum amount of emissions. These emissions are measured in terms of CO2, NOX, particulate matter and non-methane hydrocarbons. Please keep in mind that I will only be referring to diesel driven compressors. Why? Because electric driven compressors do not have issues with emissions. All diesel compressors have a certain level of emissions.

Let’s look at the main differences between Tier 4 compressors and non-tier 4 compressors. Tier 4 compressors have a superior engine technology including an exhaust after treatment and special fluids that make the emissions close to zero. I will not go into detail since this information is exhaustive and can be found in all kinds of literature. My point is: it’s very obvious that the latest technology of compressors is quite superior.

Why should you care about Tiers? Should you give preference to tier 4 compressors when renting? I will try to provide an answer to these questions in the next lines.

Let’s imagine your business is a major source of emissions, i.e., you have sites exceeding 10 tons per year (TPY) of any single HAP (Hazardous Air Pollutant) or 25 tons per year of all HAPs combined. You should definitely be worried. Anyway even if none of your sites are a major source of emissions, and you want to make sure you comply with current environmental regulations, you have to worry about this issue. The fines for violation of the Clean Air Act and selling devices resulting in excess emissions can go up to millions of dollars.

You want to make sure that your rental compressors are not adding emissions to your sites, not only because of hefty fines, but also because of environmental and health reasons. Achieving “Near-Zero” emissions with your air compressors is possible if you rent a tier 4 compressor. To give you an idea of how emission efficient these compressors are, you would need 24 Tier 4 final compressors to equal the emissions of only one Tier 1 compressor.

Other advantages of some of the Tier 4 oil-free air compressors are their better fuel efficiency, in some cases up to 25% better than non-tier 4 compressors. Longer service intervals for these type of compressors are also a nice advantage.

If you are interested in this subject, you can check more information about EPA regulations for nonroad diesel engines in the following websites: