20050609
Hi Steve, Tuisco,
I like Steve's suggestion for the adjustable vents around the edges of the roof cavity. I would suggest that you not remove the channel for the bubbles that was built along the ridge. You could also have a few liqiud cooling nozzles in this channel (unless you think that it is too difficult for drainage) and you could then try just a straight flow in and out (going across the lenght in a straight duct. Then you could close inlet vents and get a much greater flow and air velocity to see what effect that might have. Or you could close the vents to one side and so with the same blower you would see the effect of exhausting one half the volume. This would be a higher air change on only one side. The degree of chilling can be evaluated in the portion of the roof that is is active.
Air flowing into a larger shape and volume will not reach the same velocity as air that is channeling within modular sections of a roof. That is the main difference that the alternate structure design can provide. For you next step to a commercial scale I would like to see how the structure design and modular long panels that are used to form the roof - all aspects of the "package" would work together to make the chilling more effective. Then the next stage is the precipitation and separation of the vapor so that we generate dry air to recirculate into an adjoining roof panel. This air will flow to the far end of that panel and become saturated as it goes, then to enter the vortex precipitation/separation mechanism and the dry air exiting feeds into the adjoining panel. I hope you can visualize how this works and how it work more effectively with "channelled" air flow. However we can likely use the ridge channel to do the same thing with the exit (dry) air flowing into either side of the roof cavity.
So what I am saying is: don't remove the ridge duct that you made for a bubble flow path. We might still use it for bubbles or for the closed cycle chiller process that does not use the outside air but recirculates air within the cavity space.
Again, I repeat that this is pioneering work that we need to operate and measure the result - there are no guidelines to follow - this is new territory. Let me know if you have more questions. One air change per 4 minuntes for the entire roof - or, half the roof can change in 2 minutes and the ridge duct would have an air change per 1 minuite - these are our experimental modes of operation. There is no question that evaporative chilling will take place but the rate at which the process will work and the degree of chilling is something that we will need to observe from the actual operating result.
Thanks for your efforts to build our knowledge; to go from vision to a proof of concept.
Regards, Rick
tuis.petz@agrobest.biz wrote:
Richard,
Your design concerns related to the air flow in the cavities are well taken.
Please review the attached alterative design drawn up by steve. By placing smaller inlet vents alongside the cavity he suggests that the air may flow more effectively in the cavity towards the blower. An even flow will depend on the opening of the inlet vents. We may have to actually measure the airflow going through each inlet vent and where necessary close the shutters to establish a even air flow, thus increasing effectiveness. What do you think?
As I have said above this design of the inlet vents is perfect. The vent at the ridge on the opposite side to the exhaust blower should be the most adjustable - able to open to handle the total air flow, while the other inlet vents are closed or almost closed.
As I understood from our previous discussions we determined the capacity of the needed blower at an air movement of 30 to 50 Cubic meters per minute.
This would re-circulate all the air in our 200 Cubic meter cavity in 4 minutes (cavity 14 m X 14 m X 1 meter).
Will this do the job of Chilling and dehumidifying the cavity air appropriately?
Taking this in concern, how, how big and at what spot should the inlet vent be constructed?
Hi Steve, Tuisco, & Rick: I'm wondering if you're willing to post the drawing you are referring to and other relevant stuff so that us lurkers can glean something from this discussion? It sounds very interesting. Best ~ Ed