Negative pressure in basement?

[GTI]

Hey all,

I have a 40 sq meter room in the basement of my apartment block that I want to turn into a gym. There are no windows and the only air vent is a negative pressure one (i.e. it sucks). I don't know much about these things, but I'm wondering where the oxygen is gong to come from, especially if there are two of us in the room pounding away on the treadmill, cross-trainer etc..

I was also thinking of perhaps placing a portable AC unit down there and feeding the exhaust vent up to the negative pressure vent in the room so all the hot exhaust is sucked out. At the moment the room is a fairly constant 25 degrees C and it feels a little humid, so the AC should reduce the humidity and keep the room at a more comfortable 18 - 22 degrees C. Any issues there?

Cheers in advance

[B B Leo]

i wont use the vent as an exhaust m8. if its design to pull air in and not out!

[Over Carl]

You may want to look up the specs of the intended ac unit - some have a specified maximum length of the exhaust duct - we got some portable a/c units in at work as we were thinking of converting the basement to a workshop but then found out our plan wouldn't work because of this.

[GTI]

i wont use the vent as an exhaust m8. if its design to pull air in and not out!

Hiya mate, the vent looks a little like this (coming out of a massive metal air duct). It sucks air in, which I tested by blowing out a candle and watching the smoke disappear into it. So thats why I thought it might make a good exhaust inlet from the portable AC. @over carl, are you saying that the pressure of the AC exhaust might overwhelm the system?

[Over Carl]

@over carl, are you saying that the pressure of the AC exhaust might overwhelm the system?

The ones we got came with ducts but we couldn't add anymore to it. Apparently they tried doubling the length of the duct at a site office and it didn't cool too well and the duct was very warm.

[B B Leo]

i would more than likey say that that vent is for to create a movement of air and stop condesation/mould etc. a air blower should work mate. and that vent would take out and bad air

[JONNYG]

If you fancy yourself as a bit of a DIY'er you can buy boots that have the right size spigots on them to attach to the duct and flex off of your AC unit...
It would need you to cut a hole in the duct using tin snips and then attaching the boot using self drilling tek screws or rivets and then it would just be a matter of attaching the flex to the spigot using strangle band or duct tape...

Heres a few piccys of a boot/saddle to give you a better idea:
boots
Flex and strangle band/hose clip