Oventrop Solar Case Study

Recently there was an event hosted surrounding the installation of a thermal solar system in a “green” home. The event was promoted as an opportunity to see a hot water system going in and ask questions of the manufacturer’s rep.

The system being installed is an Oventrop System 5 (Oventrop System 5 brochure) in conjunction with an instant-on electric heater.

Oventrop Solar Green Home 

On-hand was the Managing Director for Oventrop US, Joseph Walsh. Joseph was very knowledgeable and has a good grasp of the emerging solar market in the US. 

After a thorough explanation of the system and installation, he took questions from the audience. The topic quickly turned to cost issues, and his response was that a typical installation to drive an 80-gallon hot water heater was between $7,500 and $10,000.

Joseph Walsh

The evacuated tubes that harness the sun’s energy are made for Oventrop by Beijing Solar, and are based on a design originated by Daimler-Benz in Germany, where Oventrop is based.  Joseph had a sample tube (he’s holding it on in the photo) for attendees to handle.

Also note the instant-on electric heater unit on the wall in the corner of the photo.  This heater will be arranged to provide support heat should the solar system fail to deliver the preset temperature.  For example, if the desired temperature is 130 degree and the solar can only manage 100 degrees; the unit will pick up the extra 30 degrees.

Instant On Electric Heater

Water distribution is via a PEX manifold. This photo gives you an idea of how they’ve laid things out.  The hot water is fed into a single manifold (to equalize pressure and allow a small 3/8 inch pipe to transmit better to the outlets) with separate valves for each need.  Red piping denotes hot, blue cold.  The white piping is another green building system – rainwater harvesting.  This home has two 1,300 gallon rainwater harvesting tanks buried just outside.  Water is pumped into the basement and into the lower manifold, which is completely separate from the upper blue/red manifold.  The white pipes supply the washer, toilets, hose bibs etc. with recycled rainwater.

PEX Manifold