HPS cooltube w/ winter

Well i just got my 400w hps setup delivered a hour ago. Gonna be setting it up today. 3x3x6' tent. 4 plants,all girls.

Its winter time here with it being 20 or less outside now. My tent is setup in the basement which is heated with 1 1500w heater right now. battling to stay around 60* in the basement. tent is seeing about 65* w/ 16-CFLs right now. I have a full 4inch ventech scrubber and inline fan setup as well running at about 55% power. With temps dropping its getting hard to keep the basement warm with this single heated. The tent used to be around 75 with lights on and 69 off, but its just falling. Im gonna blast heat the basement while i work today with some heaters but hoping the HPS could help a bit.

My question is should i even bother hooking my exhaust up to the cool tube right now with temps being so low? Would it help warm it up a bit without exhaust the tube for now? or will i still get enough warmth with the tube exhausted?

If I should exhaust, it would save me alot of space and duct tubing if i could do :

Scrubber > fan > light > out tent . Would it be okay to do a blow thru on the light? I know its always recommended to pull thru it but with the 3x3 i could run alot less ducting and give myself my headroom up top if i could mount the fan and scrubber in back and blow thru the light and out the tent, due to the tents exhaust ports are centered in the tent. Wish there was one set back in the corner.

Your best bet is to set up the cool tube without the vent on and see how hot it gets. I live in the South where it is usually pretty warm. But even when it does get cold I still have to run my vent fan. I run a 400 watt as well. Try it out and if it gets over 80 then hook up your fan, or if your temp is very cold at night you could try running the lights during the coldest period to try and help with heating costs. Good Luck Dude.

Thanks! Currently my flowering is 12noon to 12midnite right now as that works best for my work schedule so im awake during that time to water and change stuff if needed.

I grew in my basement a couple years ago and dealt with cold temps.
The first thing I did was put the whole tent up on a 2 inch thick piece of styrofoam. getting it off the cold cement ground makes a lot of difference. My Lights on period was 7pm-7am to supply warmth when ambient temps were at their coldest.

I ran a booster fan over the light to cool it, but did not vent it out of the tent.

That being said, completely stagnant air is a no-no. There should be SOME sort of ventilation pulling at least a small amount of air out of the tent to keep negative pressure established. This will help deter pests and help pull fresh air in.

thanks. got it all setup. not venting the tube and temps sitting at 72. about 10inch from plants. could prob go bit closer its not very hot like 6 inch off. got a fan goin that is kinda near end of the tube for the plants and moving air by light. ill keep an eye and see how it does.