Sunday, October 26, 2003
Called my parents today. They are somewhat "excited" about our project but I think they are more concerned about it. No electricity and no well water. My father, Dietmar [deetmahr], had a good point though on water collection: No matter how big I make our roof surface (i.e. the steeper I make it) I won't collect more water. Pretty simple, but easy mistake to fall for (at first). He knew because in Germany you get taxed for rainwater drainage (what a concept...) by the area your house occupies. Now he, having a "Walmdach" (meaning a low angle roof with slopes on all four sides), probably thought he wouldn't have to pay as much as the neighbors with their steep roof. Pustekuchen (that's German and intranslatable). So anyway. My beautiful spread sheet calculation did not work. Our roof, yes, has a surface area of 1,730 cu.ft. (720 in the south, 576 in the north and 434 for the "shed"). But the area it covers, and the area that for water collection purposes is only relevant, is the footprint of our house (and the shed). and that is only 1,285 cu.ft. But hey, it's still 75% of what I thought.
Okay, how many gallons of water in an inch of rain? Well, the easy way for a metrics-trained engineer (wink-wink) is to state that 1 cubic meter (mÂ³) contains 1,000 liter. Isn't the metric system nice? So here is the long way. 3.8 liter in one gallon. 1 foot is 0.3048 m (because 1 inch is 2.54 cm). So....
1 cubic meter is 1 meter by 1 meter by 1 meter. And there are 1/0.3048 feet = 3.3 feet in a meter. so 3.3 feet ^ 3 or 35.3 cubic feet in a cubic meter.
Okay so 35.3 cubic meter are 1,000 liter. That divided by 3.785 is 264 gallons in 35.3 cubic feet. Or, if you will, and you will want to, let me tell you, there are 7.48 gallons in a cubic foot.
Okay, just like in all those fancy textbooks these days...first they explain you the manual, do it yourself, do it while you are riding on a bike and have nothing to look at, way. Then they tell you how easy you could have had the answer. And let me tell you, it is way cool! Because google knows. Google has a calculator now - I kid you not. Try it: Type in your Google Toolbar (what? you have not installed a Google toolbar yet? Oh, you are using a public library computer...okay (Dan, Eva, Kara, Todd) you are excused :-O....so type in: How many gallons in a cubic foot? And low and behold there are 7.48 gallons. Okay so is Google the answer to the un-usability of the English system??? who knows....
So, since there are 12 inches in a foot, I just divide my square footage by 12 and multiply it by the gallons per cubic foot. That yields almost exactly 800 gallons - per inch of rain.
Now this was a dry year, let me tell you. No rain to speak off since July. But, as I saw today, Rochester Airport reported 20 inches of rain so far this year (normal is 40-45 inches for the whole year). With that amount of rain, we'd probably would have gotten...800...*20....16,000 gallons of water (that's 60,566 liters, Papa). So from January through October (and it rained another inch almost today, I would guess), for those ten months we would have had 1,600 gallons of water per day. Guess we're lucky, because my estimate from way back when was 1,500 gallons per month. Right now we are usually using 2,800 gallons with high-flush toilets and a really really inefficient washing machine. So a low-flush toilet, a low-flush shower head and a Staber horizontal, European styel front-loading, washing machine should do the trick to bring us down to that level.
If our water should really not last we always have some other options...Going to the laundromat to do our laundry (Wash-Center in German ;-) "Wascator" actually, a Danish (Huh?) name. Spend many hours there with my mom doing "big" laundry. Biggest memory is - why do people smoke in wash centers? strange...
Anywho...where was I? Oh yes, conversation with my parents. Well, now that I've done the math, I think I am still okay. Don't remember what my father said about their or JÃ¼rgen's water usage. Maybe 10,000 liters per month (that is 2641 gallons, so comparable with what we use here). I'd be surprised if they use more.
I still have to complete the water usage spread sheet. Especially for factoring in our water usage for having a child. Oh and tank size. I originally wanted to go with thre 1,500 gallon tanks. But since it was so dray this year maybe we'll increase that. And I also only found 1,700 gallon tanks for almost $1,500. Ouch - that is $6,000 for 6,800 gallons. But I guess that is still cheaper than the $22,000 for the well, given that water is 500-600 feet deep (150m to 180m). And we also are concerned with the quality of the water (due to field runoff of chemicals that just rush through the soil because of the underlying porous (?) lime stone. And our friend Barb's well just ran dry this summer. Boy that would suck if you invest 22,000 get chemicals in your water and in a few years it runs dry because of all the development that is going on.
Rainwater. Somehow it is stuck in my mind that it is very soft. I guess it is common knowledge but I think it was implanted in my brain through laundry detergent commercials, I think. Or, wait, I think I had friends and he, yes, Barbara & Holger, he installed rain water collection system and they used it for their laundry only (separate plumbing) and they said it is really soft.
Okay, I guess it's time to go to bed now. So: in a good year (45 inches) we'd have 32,000 gallons of water or 2,667 gallons per month. In a bad year we'd still have 1,300 gallons per month. Not too bad. And 6,000 gallons would give us roughly 4 months. I'll talk about evaporation and snow-wetness another time. That is another spreadsheet I prepared in August. And I also was able to explain our current water usage and show how with the same (or similar) usage patterns we would come down to 1,500 gallons. But it is time to go to bed now. Hope you're enjoying this stream of consciousness. I do ;-)
P.S.: Meant to give Jürgen & Susi a call for ages. So excited about their moving plans. And I really would like their feedback on all our ideas and thoughts. Oh and also need to write about the upcoming design reviews. and our walk with Kirby & Sarah last Sunday (gorgeous day). If only I had time ;-)