Hey gang, I'm a home brewer and had built my own beer frige for the home. Now this project was bigger than most folks dare to engage in because I salvaged parts from several old fridges to bring it together. I calculated the CF of my coldbox to be approx. 19CF and gathered parts to match. All being said the item has served me well for the better part of five years now. Well of course as time goes the performance has wained and it's time for that general overhaul. My questions involve the construction of a new evaporater. The old one was the cooling tubes festooned with hundreds of little aluminum wires and a fan assembly that lacked the CFM's I feel were needed to bring it to temp. rapidly. The beverage thermostat that I used rarely if ever cycled the unit off as it took all it had to bring it to 45 deg.. So my plans to build an entirely new evaporator unit seems justified. I've got a different type coil and fan in mind, the new coil is the standard aluminum fin type once more sized for a 19CF. In addition the new fan assembly is the double squirrel cage type that was salvaged from a upper grade range hood. I feel these upgrades in addition to a design that insures every cubic foot of air MUST pass thru the coil are possibly enough to show a major improvment in performance. As far as the condencer goes, that seems fine other than the fact that it does get a bit warm. My upgrades do include some measures to maximize air flow there as well. My MAIN QUESTION is Im very curious about the evaporator cabinet. I'll be housing the coil and fan assembly in it and wish to know what influance headspace has on the suction and or discharge side of said cabinet. Is there a formula? Should I not concern myself with headspace? Thanks in advance for any help on this.