|Project by RVroman||posted 02-24-2013 08:53 PM||1792 views||1 time favorited||9 comments|
I have been meaning to build a ventilation fan for some time now, and all the recent ones posted spurred me to actually do it. Because of space restrictions, and what I had available to me, I went with tube fans rather than a squirrel cage fan. They are each rated at 1590 CFM, but that is reduced by the filters, so I am not sure what I am actually getting. However, as seen in the last picture it does work as evidenced by the dust on the filter (I used my air compressor to “kick up some dust” to test it).
I decided to insulate between the fans primarily in an effort to make sure air was only moving back to front. I do not think this would be as much of an issue in tube fans as it would in squirrel cage fans, but I figured “why not?”. This also helped cut the noise down a bit, which I did not expect since the motors are inline with the airflow.
I originally designed it for either two 1” filters, or one 1” filter and a layer of the same filter material you might find on the back of a humidifier. However, that really seemed to cut down on airflow. Once it was hung I changed the plan a bit and added angle iron to make a bracket for the filter. With one filter there is much better flow, and it is easier to change as I do not have to cut the filter to fit the box. Rather than building the box to fit the filter I had to make the box fit my space and the filter fit it. What cannot be seen in the pictures is that the extra 2” of the filter at the top are between rafters, while the box itself is attached to the bottom of them.
I took an idea from another fan post here on LJs and used a Christmas light timer. That way I not only have the remote, but can set it for two hour increments up to 12 hours, or just have it on all the time. So far it seems to be working well, but I am going to play with different filter combinations. I am thinking of adding one to the front to catch anything that makes it through the rear, but CFM reduction will have to be taken into consideration.
Glued and stapled except for the bottom and front which were screwed to allow access
Fans: (74.99 plus a 20% coupon off the entire order) http://www.harborfreight.com/8-inch-portable-ventilator-97762.html
As always thoughts and ideas are appreciated. I would love to make it even more efficient if anyone has ideas for that.
-- Robert --- making toothpicks one 3x3x12 blank at a time!