by jayt
Question regarding reservoir width/location
8:51 am in Getting Started, Materials and Resources, Projects in Process, questions, Seeking Advice by jayt
Hello. I’m about to begin my window farm, but I had a quick question. In the Reservoir System instructions , the minimum width for the reservoir is 47″. Is there any reason that it must be that long? If I only wanted three columns (instead of four in the diagram), could my reservoir be ~36″? Also, is there a functional reason for the lower reservoir to be suspended instead of resting on the floor? Thanks in advance for the advice.
Hi Jay,
I’ve helped install a few Windowfarms and can lend some advice.
I think the reservoir can be shorter – 36″ should work for 2 strands.
I believe we had installed one at 40″ wide, an image of that one here:
http://www.flickr.com/photos/8269551@N04/3794379889/in/set-72157622330681110/
Also, yes there is a functional reason to elevate the lower reservoir off the floor.
Most water pumps have a limit on the height to which they can push the water.
Elevating the bottom reservoir (and pump) reduces the vertical distance the water needs to travel to get to the top, as compared to having it on the floor. Check the specs or your pump, or better yet, test it in the shower to see how high it can push the water column. Have fun!
Jay,
There is a reason for the minimum width. You don’t ever want your water pump to suck air. I came up with this algorithm– I’ll have to find it again and post it– where I calculated the flow rate for even the smallest pump and the time it takes to suck all the water out and how many gallons a tube of a given length holds and the minimum on/off time for the pump timers. 47″ was the smallest we thought you could get away with before you started putting extra wear on your pump by running it dry. We lost one pump that way already.
However, a guy at a recent workshop talked about having found a programmable timer that was more sophisticated than the best one we had found. If I can track that guy down and get him to send me the link, that may be your savior. You might do a little internet searching yourself and see if you can find a timer that offers more on/off cycles and more programming functionality than the one we recommend. If you do find one, please make a post about it!! That is one of the biggest limiting factors in the system so far!! B
Oh. The other thing you can do is use 6″ diameter sewer pipe instead of 4″ diameter. Quicker fix.
Thanks for the input, Ted and Britta, it was very helpful. If you could post that algorithm, that would be great Britta. I would prefer to house the bottom reservoir inside my window frame (which is 42″ wide) if possible. But, if that will cause the pump to overwork, I can try to figure something else out. Also, where in NYC did you get the pipe for the reservoir? I have been unable to find it at several hardware stores. Thanks again.
Prince Lumber has 4″ diameter sewer pipes. Get the ones with 1/8″ thick walls rather than 1/4′ thick walls if possible- they are lighter and hold more. Not sure if they have 6″ diameter pipes. Try Mcmaster.com for 6″ diameter.
I’m writing a post about the pump algorithm.
Hey Jay, Are you in Manhattan? A reporter contacted us and wants to interview someone building a windowfarm in Manhattan this week. Do you want to do it? If so, shoot me an email britta [at] windowfarms [dot] org.