I finally tried out my new rainwater laundry system today. The barrels were about 15% full from the last two or three rains. The electric point-of-use tankless water heater was installed last week.

I was disappointed that the water didn’t come in very hot, but that’s probably because the incoming water temperature was very low. The heater I had installed, an Eemax EX95TC, is a 9.5 Kw unit with a temperature rise of 65 degrees at 1 gallon per minute. The incoming water was probably 45-50 degrees, so the hottest the hot water got was 108 degrees. I was hoping for 115 to 120.

Because the flow rate of the hot water was limited to 1 gpm, the cold water came in 2 or 3 times as fast, so they didn’t mix evenly to make warm water. If I wanted to wash in warm water, I would have to set the washer’s temperature to Hot, but increase the flow of the hot water to 1.5 gpm.

I’m still learning how to make this work. I expect the heater to work better in Spring and Summer when the incoming water temperature isn’t so low.

I did four loads: two large, one medium, and one small. These reduced the water left in the barrels by half, from about 500 gallons to 250. The water flowed from the barrels very smoothly, pumped by a Grundfos MQ 3-35.

Overall the system worked well, and I’m waiting for the next big rain to do another four loads of laundry. This probably wouldn’t work for a big family with a lot of children and piles of laundry every day, but it works just fine for me.

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7 Comments

  1. Marci,

    I have two 1250 gallon tanks for 2500 gallons altogether. The indicator is in inches. The tanks are 80″ so 20″ is 1/4 full. So far the indicator hasn’t reached 20″ yet, but looks like it might be 10-15″. It’s a small dial and doesn’t have many markings on it and it is hard for me to see it from a few feet away. So I’m just guessing at how much water is actually in the tanks right now.

    Come on over and take a look for yourself. I’ve got a cold now, but maybe we could go to lunch next week.

  2. There is a good chance your Grundfos pump was manufactured in Fresno, just north of the house where I lived before I moved to San Ramon. Most people only know Fresno from the farms and motels you see as you drive down Highway 99, but there are a lot of small industries there, like Grundfos Pump manufacturing and the ZIPLOC bag manufacturing plant I used to manage 20 years ago.

  3. Paul,

    That Grundfos pump is very well made and works like a charm. I thought it was Swedish. I’m glad to hear it was made locally. The barrels, PVC pipe, and Eemax water heater are American made too.

    Going green shifts jobs from one sector where they have already been lost and moves them to another with tremendous growth potential. So why are politicians in Washington, D.C. fighting it?

    Roz

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