NEW AIR CONDITIONERS. Our DTS 3661C (NEMA Type 3R/4) new improved version of our former DTS 3661 indoor cooling units, have the highest Cooling Capasity Per Density (CCPD) available on the market. Housing: galvanized sheet steel. These units are ideal for high heat loads, especially high horsepower drive enclosures. Cover: electrostatically powder coated RAL 7035 (light grey) or ANSI 61 grey. 460 VAC.