this is the tent setup.
Extractor fan external, scrubbing the tent.
Passive intake on the bottom front [not visible], extraction vent top back [visible in pic].
This is the new addition in the tent as of yesterday.
Air-con.
Situation is, I'm suffering a Spanish summer with HPS lights and looking at signs of heat stress on the baby girls.
Temps in tent are 30 -32.
Ambient temps of basement were 26.
So the extraction fan was sucking in 26 air to cool 31 degree tent air.
So I bought the air-con to provide a source of cooling air.
Have had to exhaust the air-con into the basement room because there are no windows in the basement, so unless I drill a hole in an external wall, I have no way of venting the warmer air out of the grow space.
With the air-con on the basement ambient tents have risen to 30.
In tent is now cooler than outside the tent.
BUT, it now means I have had to turn the extractor fan off, so that I'm not sucking 30 degree basement air, into a tent with temps of 27.