Heat exchanger with louvered fins

A method of exchanging heat between a first fluid and a second fluid in a fin and tube heat exchanger, comprising:

• flowing the first fluid through a plurality of tubes;
• flowing the second fluid between a plurality of fin plates, the plurality of tubes extending through the plurality of fin plates, each fin plate of the plurality of fin plates comprising a planar portion having a plurality of louvers disposed on the planar portion, each louver of the plurality of louvers comprising an angled slat that includes a leading edge that extends above the planar portion and a trailing edge that extends beneath the planar portion;
• exchanging heat between the first fluid and the second fluid;
• wherein each fin plate of the plurality of fin plates includes an attachment flange that comprises a semi-circular boss;
• and
• wherein adjacent fin plates of the plurality of fin plates are attached together via the attachment flanges.

A heat exchanger for exchanging heat between a first fluid and a second fluid, comprising:

• a plurality of fin plate columns;
• a plurality of tubes with the first fluid therein extending through the plurality of fin plate columns;
• wherein each fin plate column of the plurality of fin plate columns comprises a planar portion with a plurality of louvers extending between the plurality of tubes such that the second fluid flows through the plurality of louvers, each louver of the plurality of louvers comprising an angled slat that includes a leading edge that extends above the planar portion and a trailing edge that extends beneath the planar portion;
• wherein each fin plate of the plurality of fin plate columns includes an attachment flange that comprises a semi-circular boss;
• and
• wherein adjacent fin plates of the plurality of fin plate columns are attached together via the attachment flanges.