FAQs for the Answer Dan:

Do I want flatplate or evacuated tubes for my solar hot water system?

After analyzing data from various sources for flatplate and evacuated tube collectors, I find that flatplate collectors perform better in the majority of situations. There are also considerably more cost effective. However, the SolVelox Glycol can be used with all types of evacuated tube collectors and flat plate collectors.
For more details about collector types, I recommend an exerpt from Solar Water Heating by Bob Ramlow with Benjamin Nusz at
http://oikos.com/library/solarwaterheating/collector_types.html
Click here for another article which explores the performance differences between flatplate and evacuated tube collectors.


Why would I get solar instead of instantaneous water heaters?

Instantaneous water heaters only replace about 15-25% of the energy used by a conventional water heater while solar water systems replace 70-90%. An article by Consumer Reports states that the tankless heater "savings can add up to some $50 per year compared with conventional heaters. But even at that rate, it will take more than 25 years for an average household to recoup the extra $1,300 or so those units cost to buy, install, and maintain." An average family can expect $300-500 savings each year.