Lots of folks dont think LED put off heat, but they do. Though it is less heat than equivelant HPS, its still heat. Plus a lot of folks forget to mention that unlike a HPS/MH hood that can duct heat away from the room -most LED manufacturers dont make a convenient way to exhaust the heat from the LED out of your room. You have to cool your room vs exhausting the heat out of a grow room through a duct to relieve high temps. Though LED has afforded me the ability to grow in the summer months, HPS still holds a place in my rooms. Here in MI, I rely on the heat from the HPS to heat the rooms in the colder months.Its a win/win.