Approximatelly 85 percent of a HID lights is in wavelengths providing heat. So (2000 * 0.85) = 1700 watts of heat. (1700 watts * 3.41) = 5797 watts. A typical air conditioner provides 1200 btu of cooling per hp. That means it would require a 1/2 hp chiller or air conditioner to remove the heat added by two 1000 watt lights. Simply put, it would require the use of a $150 (Sears Kenmore) 6000 btu air conditioner that uses approximatlly 600 watts to remove the heat. A 6000 btu chiller (1/2 hp) would cost a great deal more at approximattely $800. Plus a chiller in this price range would exhaust the heat it removed into what ever room/space in which it occupies. If using a cheap window air conditioner the heat would be exhausted out side but no odor would be exhausted. However that would require your grow area to be located with a window available. There are double hose portable units avialble but they are about 3 to 4 times as exopensive as a window unit. This means to grow at temps up to 70 to 75 degrees you would also need to provide fresh air intake constantly (when lights are on) to insure adequate CO2. Even with a chiller or air conditioner you would be limited to temps that are proportional to the amount of CO2 available. Ambient levels of CO2 are quite low at less than 400 ppm. At temps of 75 to 80 degrees for maximum growth you need 1200 to 1500 ppm. For good growth in the 80 to 90 degree range you need 1500 to 2000 ppm. Or you would need CO2 isupplementation to utilize higher temps of say 80 to 85 or even 90 degrees if you system is aeroponic or hydroponic. That much lighting is essentailly more lighting than waht can be reallly used without CO2 supplementation. even with cos nstant air flow it is a waste of lighting as not enough CO2 is available for optimum usage of that amount of lighting. Plus with soil grows it takes a lrage pot to provide for the large root system needed to supply the water and nutrients need to utilize that much light. CO2 supplementation allow the use of high wattage lighting without haing to pay to remove all the heat the lights produce. However, even with CO2 supplementa\ion the temps stiil usually require some heat removal. As mentioned by another replier water cooled lights are an option as they removed about 75% of the heat from the lights to a resrvoir of water but you still need to remove the heat from the water. This requires a very large reservoir or a chiller used to cool the water in a smaller reservoir. If you have well water from a shallow well then that water would provide a cheap cooling sourse but you would be using and discarding the water. However your only going to need a 1/4" water line at about 35 psi to carry away the heat from 2000 watts of lighting so the cost is not highh. Some aeroponic and ht ydroponic growers use the water for cooling to supply the water to there RODI filters. You get double use of the water and a RO filter works more efficiently with warmer water that the usual tap water temperature used. As long as you can use thatt much RO water you are money ahead of using a chiller or air conditioner.
Too much info?