A/C Vent Booster Fan





Introduction: A/C Vent Booster Fan

We have some rooms in our house that never seem to cool down because the A/C doesn't seem to move enough air. I've been told to make sure the filter is clean and NOT one of those pleated hypoallergenic ones, (cheap free-flowing is better for a/c), open all the vents and leave the thermostat fan switch in the ON position; notAUTO. Some rooms just need a little boost though, so we found this little fan that fits over the vent. It works great but cost $35.
I started withe a 4" fan and a plastic tub that fit over the register.
Find a fan that you can take apart or it'll be more work if you have to drill and pop-rivit it back together.
I had to drill rivits  and remove the stand (watch your fingers...)
I attached the cover to the inside of the tub and carefully cut out the inside, leaving a little extra around the screw holes.
After re-assembling the fan, I drilled a hole for the cord.
The finished product with cool feet.



    • Water Contest

      Water Contest
    • Oil Contest

      Oil Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    12 Discussions


    1 year ago

    post addition. For those who would like a visual of what a butterfly valve is, when referring to my earlier post.


    1 year ago

    Mechanical Engineer here, ... essentially the same problem in my two story home. Typical complaint, hot upstairs during summer a/c use. .. overly hot downstairs during winter furnace use. Inefficient ducting is the cause in almost every case. Problem with my home is energy cost in both seasons, even with solar it has been $600 month during peak of both seasons.

    HVAC wanted $2500 to redo ducting, install baffles .. ect. Instead I purchased cheap 12v solenoids (2) , roll of HD doorbell wire, 2 position switch, 12v transformer and made "butterfly" valves. I installed them inline on the main ducting for upstairs, downstairs. Total project took 2 hours.

    Now, a simple throw of the switch ( mounted to thermostat ) either increases overall a/c output upstairs for summer, or switch lower position increases furnace output downstairs. Huge difference, monthly bills now sub $200 ( with solar ).

    Total project cost ... $85.00

    This ducting control is much more effective than trying to push or suck air out of vents with a fan. It's also more cost effective in the long run with comparable project costs. I'm actually surprised that you don't find these kits ready made at the big brick and mortar stores

    I am also suffering from the same problem but due to my tight schedule i am not able to clean the dryer but with the help of your post I will be able to clean the dryer vent easily.


    I have the Suncourt model you have as a demo. It works well but it cost around $30. I wish I would have made this inexpensive model. If that one goes out I will be making one of these cheap models and putting it on a wall timer. That way it won't be goes 24/7. A kind of set it and forget it. But good cheap concept. I mean it's the same as the name branded.

    I just bought a new heat exchange fan at the Good Will for $2.00 I figured at that price Id find a use for it.

    not a bad concept.....but, HVAC tech here.....the best way to get vent output is to close the other vents (proportionally).....especially the one closest to the thermostat....circulate air out of the room with low vent psi with a small fan (at floor level)....air will stagnate at floor level and cool air will not penetrate the denser air......a laminar airflow out of the room towards the nearest air intake will form a vacuum at the cool air register......remember, there is a limited amount of air coming from your air handler / furnace if the vents closest to the furnace HVAC are fully open there is little pressure available for the outlying vents....

    1 reply

    hvac tech here to and i say get an air balance .. you could jump in your roof and do it if it has damper blades on the outlets.
    Also make sure your indoor coil is not dirty.

    Nice! I did something similar, albeit not as pretty. I sealed a 100 blade blower fan to the vent. The room is now often 10 degrees (F) cooler than the hallway leading into it.

    AWESOME! My bedroom gets very little cool air from our central heat and air system, and I have been roasting all summer. I will try this one. THANKS!