Tuesday, April 19, 2011

New Passive Solar Domestic Hot Water System Debuts

There’s a new passively pumped solar water heating system
that greatly simplifies the typical cold climate domestic hot water (DHW)
installation.  http://www.sunnovations.com/

For me, the holy grail of solar DHW is a system with almost
everything missing:

1.  No pumps
2.  No controller
3.  No sensors
4.  No electricity required
5.  No valves
6.  No stagnation or overheating problems
7.  No chance of freeze damage (freeze tolerant, at least)
8.  PEX  allowed
9.  No heat exchanger
10. No antifreeze

11.  Can use a storage tank purchased at Home Depot

 This system provides 1-8, but it does have an in-tank heat exchanger and propylene glycol.   I’m not on my knees, but this is  not bad!

 It operates by resurrecting the Copper Cricket style geyser pump.  They solved overheating with a steamback-like method, and can use anyone’s  harp style collector.

Prices are  taboo on the company's website.

 The CEO, Matt Carlson, explains that  "the installed cost varies by region.  It is influenced by the cost of labor, competition, shipping cost, configuration of the home, permitting costs, and distributor pricing, etc."

 Ballpark prices can be obtained through direct contact, though:


Here’s another discussion of how the Copper Cricket worked:


And why it fizzled:  http://www.heatinghelp.com/forum-thread/133419/Steam-Pumping

The patent can be viewed at  http://www.google.com/patents/about?id=f0LWAAAAEBAJ&dq=7798140



    Since this geyser pump really could be a game-changer, I got one installed on a rental house of mine as quick as I could. It is percolating just fine. If you're used to systems where heat rises, this thing seems like magic. The flowrate is a bit low, but I will have energy savings data shortly.

  2. Thanks Kevin for pointing this out. Please keep us up to date on your Sunnovations unit. I'm interested in installing something like this at my multifamily complex.

    Also, could you share how much you paid for your unit? Thanks

  3. As a "qualified installer" they frown on me publishing my price.

    Right now in Denver, customers tell me the other dealer will quote $8k-$9k. I can install a two panel system for $5500 to $6500.

    With today's natural gas prices being so cheap, it's a difficult investment to justify. Of course, there is a 30% solar tax credit that helps a little. The Governor's Energy Office often has an additional $3000 rebate as well.

    For a multifamily building, the economics are a little better. Expect to pay about $1600 -$2300 per apartment. The rebates available are correspondingly larger.