Mechanical Water/Condensate Harvesting

Here in Santa Barbara in 2021, we have just been through the rainy season that almost wasn’t. We got a few good downpours and that was about it. Many plants that are usually nourished by the winter rains really didn’t get any significant watering. Soils didn’t get a deep soak to help plants survive without extra irrigation in the spring months. What’s a caring water wise person to do?

At Sweetwater, we are drawn to innovative sources of water. One of these that is rarely talked about is mechanical water harvesting or condensate harvesting (condensate being one type of mechanical water). Although I don’t encourage use of air conditioners, and they may still not be in common use in some parts of our fair city, residents in other areas, and during certain times of the year, are using air conditioners more and more. Climate disruption promises to give us both much hotter days and longer periods without precipitation followed by torrential rains.

“Ample condensate typically collects on the cold coil of air conditioner and refrigerator units, which is often wastefully discarded via a drain or pipe. The hotter and more humid the climate, and/or the more moisture (such as from respiring and perspiring people) in an air-conditioned building; the more condensate air conditioners, refrigerator units, ice machines, and freezers will discharge.” Brad Lancaster,

HVAC condensate from seven buildings at Rice University in Houston…” is captured and pumped back for reuse on campus, primarily as makeup water for the central plant’s cooling towers. …Rice recovers about 14 million gallons of water per year, and that is probably a conservative estimate. That means that instead of buying 14 million gallons of treated, potable water from the city to replenish its cooling towers or tapping the university’s own well, Rice saves a precious resource and a considerable amount of money.

Condensate is considered good water — as pure as distilled water, low in mineral content, and can be used for a number of applications in addition to cooling towers.”

In February 2018, in a hands-on workshop, Sweetwater Collaborative created a tropical garden at Kiva Cowork (formerly Impact Hub) in the Funk Zone. The garden, consisting of a banana tree, two coffee plants, and a passion fruit vine, is watered primarily with air conditioning condensate water. Stop by and see the magnificence of the banana tree, which is in flower with fruit maturing on it at this point in time. All of the plants, tucked in at the corner of the parking lot behind the building at 10 E. Yanonali, are flourishing.