Sunday, October 18, 2009

Moving hot air from ceiling to floor

I have been contacted by a lady, Kari, that has a vertical pipe that she uses during the winter to move hot air from underneith the ceiling to the floor in her small house. It is about 8 ft tall, 4 inch wide and has a 7W fan inside the pipe. In her first year in the house she was often cold on her feet, but after installing the vertical air transporter her feet were much warmer. Before starting the fan in the morning she measured 18C (64F) three feet off the floor, and 13C (55F) at the floor. After running the vertical air transporter for 3-4 minutes the heat was distrubeted more evenly such that the temperature at the floor also was 18C (64F). She claims to have saved a lot on her heating bill by using this for one winter, comparing it to the heating bill from the previous winter. She has been trying to get Enova interested in the consept and get them to promote the consept as a general energy saver in Norway, but without much luck. So is this a working consept for saving energy?

I think it can be compared to using a celing fan. During the summer it blows cold air down at you and you feel cooler because of the wind chill factor. During the winter it can be reversed to slowly rotatet the air up and then down the sides of the walls. It must be done slowly so it does not create any noticeable wind chill factor, as it will make the air feel cooler. Slowly mixing the air evenly is known to save energy during the heating season. Energy Star: Using the Ceiling Fan Year Round It should not matter how you mix the air as long as it is done slowly. Kari measured as much as 5 C difference between floor and 3 feet up. I would think that in particulare a house with cold floor will benefit from mixing the air, as this will probably be where the highest difference is in vertical temperature. If mixing the air will help you lower the average temperature in the room with 5 C then the saving would be as if you turned down your thermosate with 5 C, which should give a noticeable difference on your heating bill.


Anonymous said...

This is exactly what I am trying to do in my shop. The front shop has a double height space with a mezzanine. Upstairs gets v hot while downstairs is freezing. Would like to know what fan she used and where it was within the tube. I have an idea to attach the fan to a solar panel.

Svein* said...

Not sure exactly what fan it was, but it was within the tube, perhaps something like this,Product.aspx?artnr=32-2202