What’s wrong with my ventilation?

I have an area of approx 3 X 4 X 3 meters and have installed a 150mm exhaust fan with a carbon filter on one side of the room close to the ceiling, I also have an inlet fan on the opposite wall. The problem is the room smells, the 150mm fan is stronger than the floor fan, is the ceiling fan taking all the good air out of the room? I thought the odour would rise to the ceiling allowing the ceiling fan to extract the smell.

A carbon filter will clear the air that goes through it. If your room has smells in it, the room will stay exactly the same and the exhaust air will be clean.

If someone told you the filter would remove the smell from the room, that isn’t true. If you move air at the normal rate, the smell stays the same inside the room. If you double the rate the air goes through the room, the smell is diluted by twice the fresh air. So move more air to dilute it maybe. Smells do not necessarily rise, but old air heats up and rises.

I usually recommend putting an ozone generator in the room instead of the carbon filter.

1. Ozone (03) reduces mould
2. Ozone generators add negative ions to the air which improves growth and health of plants
3. The activated (charged) carbon is usually affected by humidity, and loses its static charge. Many growers bring their units back to me saying they stopped working, but work again during winter.
4. Ozone oxidizes smell and can be used to eliminate the smell from the source, meaning the house won’t stink, so the exhaust will not smell, the room will not smell, and the hallway, roof cavity etc will not smell.

Overusing ozone is dangerous so use a 1 hour dose to set it up, and then use around 15 mins per hour to remove smell. Then add or subtract 1 or 2 doses at a time if the smell is still there, or if the ozone smell is too strong. Ozone generators start at $250

Your fans seem very small for that area. I usually run that with an air conditioner or 4 times the air power at least if no air-con available.

Good luck