Post by lamazoid on Dec 17, 2015 23:17:16 GMT -8
Hello Gary and others!
Recently i've been working on new project related to energy-effective housing.
It started when i've found this thing:
www.marley-germany.com/en/products/ventilation/fresh_air_heat_recovery_unit/unit_detailstechnical_specifications/index.htm
And decided to make one with some kind of cheap scrap materials.
The main problem was ceramic heat exchanger element, i had no clue where to find it. But when i have shown this picture to my friend, who is working in automotive repair workshop,
he said immediately: its automotive catalyst! We've quickly found one on workshop scrapeyard:
"now everything should be simple" - i thought.
It's just a question of some simple electronics ( a 555 timer or microcontroller either), ventilation shaft, and... fan.
I was wrong. What has seemed to be simple, appears to be another trouble: reversible direction fan!
Original idea was to get a PC case fan, something about 100-120mm size, and make it spin in both directions by some alternations of internal control circuit.
But in fact, the blades of this type fan are designed only for single air direction, and just reversing it will result in poor performance.
So this has to be some special type, bidirectional fan.
I dont have any clues where to get one, maybe someone other has, thats the reason why i'm posting this.
Currently i have a temporary solution: take TWO computer fans and place them opposite each other. I have no doubts that it will work and do the job (e.g. recover heat and ventilate rooms, if you still remember the goal
) , but from engineering point, that does not look very nice 
Recently i've been working on new project related to energy-effective housing.
It started when i've found this thing:
www.marley-germany.com/en/products/ventilation/fresh_air_heat_recovery_unit/unit_detailstechnical_specifications/index.htm
And decided to make one with some kind of cheap scrap materials.
The main problem was ceramic heat exchanger element, i had no clue where to find it. But when i have shown this picture to my friend, who is working in automotive repair workshop,
he said immediately: its automotive catalyst! We've quickly found one on workshop scrapeyard:
"now everything should be simple" - i thought.
It's just a question of some simple electronics ( a 555 timer or microcontroller either), ventilation shaft, and... fan.
I was wrong. What has seemed to be simple, appears to be another trouble: reversible direction fan!
Original idea was to get a PC case fan, something about 100-120mm size, and make it spin in both directions by some alternations of internal control circuit.
But in fact, the blades of this type fan are designed only for single air direction, and just reversing it will result in poor performance.
So this has to be some special type, bidirectional fan.
I dont have any clues where to get one, maybe someone other has, thats the reason why i'm posting this.
Currently i have a temporary solution: take TWO computer fans and place them opposite each other. I have no doubts that it will work and do the job (e.g. recover heat and ventilate rooms, if you still remember the goal
) , but from engineering point, that does not look very nice 
(actually, you can consider yourself lucky if that is really google translate...
