How much heat should I expect from a 150 watt HPS?

I'm going to acquire a 150 watt HPS kit soon, to add to my girl 35 days into flowering. I was wondering how much heat I should be expecting the kit has a small built in fan it looks like.

i have a 150w HPS and they do still generate quite abit of heat. i use it in my grow tent and temps get in the 90's sometimes. but with good ventalation and fans blowing should help..

your better off buying a 250 hps , the difference between the 2 in heat is very close.

Well currently 150 is the only one I can find/afford. Also I have two 9 inch desk fans at the bottom of my girl and they're constantnly blowing so I think it may be enough.

To me it does not seem like much heat at all. Traded out around 250W of CFLs for a 150W HPS and feel little to no difference.

Growgirl, makes a good point. What lights do you have in there now?