Noise attenuation units are disclosed that are connectable in a system as part of a fluid flow path. Such units include a housing defining an internal cavity and having a first port and a second port each connectable to a fluid flow path and in fluid communication with one another through the internal cavity, and a noise attenuating member seated in the internal cavity of the housing within the flow of the fluid communication between the first port and the second port. The noise attenuating member enables the fluid communication between the first port and the second port to flow through the noise attenuating member.