Its a 1000watt ballast, and i ordered 2 bulbs one MH/ and one HPS, figure ill ues the MH for vegg, and the HPS for flowering, not sure on the heat but i am growing in my basement and it stays cool down there all the time and if i do have heat issues i saw an idea i liked on here where a kat tapped into on of his centeral heat and air ducts in his basement and i fugre it worked for him it will work for me.