A reflow apparatus for solder joining electronic components to a substrate includes a reflow chamber, a conveyor to convey a substrate within the chamber, at least one heating element to provide heat to reflow solder on the substrate, and at least one system to remove contaminants generated from the reflow solder. The system is coupled with the chamber for passage of a vapor stream from the chamber through the system. The system comprises a contaminant collection unit in fluid communication with the vapor stream. The contaminant collection unit includes a coil and a collection container. The coil is configured to receive cooled gas therein. The arrangement is such that when introducing cooled gas in the coil, contaminants in the vapor stream condense on the coil, and when ceasing the introduction of cooled gas in the coil, contaminants in the vapor stream are released from the coil and collected in the collection container. Other embodiments and methods for removing contaminants are further disclosed.