My $200 home ventilation system - if you are on a budget.. I recently decided to re-purpose a few bits-n-bobs I been using in my shed as an extractor fan for removing the dust from all my woodworking projects.. This may not suit every home and if you wanna spend thousands of dollars on a ventilation system don't let me stop you.. But if you want a good solution without busting the budget, here's how i did it.. and BTW it works perfectly.

When you break it down, 'most' ventilation systems are simply:

1) A fan to bring fresh air into your home.

2) Some ducting to place that air in a few locations in your home.

3) Some control unit to tell the fan when to come one and off

4) A filter - mostly required if you bring in rubbish air from in the ceiling space. or you live in an area where the air needs filtering, I live on the pure West Coast :-)

Our house is 120m2 with 2.8mtr ceilings and in the mornings the windows in the kitchen/lounge/dining area would completely fogged up with condensation.. such that my first job of the day was to get out the WindowVac out and clear all the windows..

My System

1) I placed an inlet grille high up in the gable end of the house. The grill is protected by a 500mm soffit so until the day comes that I am getting horizontal rain, it doesn't even have a cowl cover, but I might add one one day.. It does have mosquito mesh inside to stop the bugs coming in.

2) The fan is suspended from the rafters about 3 mtrs in from the gable.. I fitted a back-flow preventer, to stop the warm air going out, or cold air coming in when not wanted. Another 5 mtrs of ducting brings 362 cu mtrs of beautiful fresh West Coast air into the centre of our main living area, which is also pretty much the centre of the house.  

3) My control unit is a light switch which was left over from a ceiling light I removed. 

My manual system works fine for now.. and I simply turn it on during the day between about 10 and 4pm depends on how cold it is outside.. I have found that even when the house is nice and warm.. around 18 to 22 degrees, that as long as it's more than about 12 degrees outside.. the inside temperature stays about the same.. I guess by redistributing the hot air that hugs the ceiling.. In fact even if it's quite cold outside but we are cooking.. turning the system on pushes out the stale cooking air and keeps the temp up.. 

End result, no condensation on the windows.. and generally humidity has dropped all around the house.. I guess this simple system wouldn't suit homes where the bedroom doors are mostly left closed, but it suits our situation well. I might fit a simple time later if required.. or even make up a switch that turns it on and off when the temp ouside goes above or below a certain temp. But for now it works fine.

If you think something like this will suit you.. I see the same fan I have is part of a bathroom extraction system for sale for $99 at the moment at Trade Depot Look for Weiss Extractor fan .

That system comes with just 3 mtrs of ducting, so you would need to get more ducting as required. I did use a vent similar to the one that comes with that system for my inlet.. but for the ceiling I bought the diffuser type that pushes the air horizontally, as opposed to blowing it downwards. I found that moving the air along the ceiling instead, more effectively mixes with the warmer air on the ceiling..  

Hope this helps some people. and thanks to all those who have helped me on these forums.. and those who post really great information.

Here's the fan specs

• Motor: 230-240VAC 50Hz 0.4 Amp (twin blade inline fan unit)
• Motor Insulation Class: B1
• Motor Protection: Thermally Protected
• Free Air Fan Performance: 362m3/hr / 100.6l/sec