Solar hot water in a box

• Manufactured by Fafco
• 877-554-6826; www.hot2o.com
• Cost of Hot2O system and 48 sq. ft. of panel: $1800

Skeptical? I sure was until I saw this product demonstrated at this year’s International Builders’ Show in Orlando, Fla. In a single box, you get a Hot2O solar hot-water system that works with your existing water heater to provide hot water for up to four people.

The system consists of two 2-ft. by 12-ft. flexible polymer panels about 1/4 in. thick. They come rolled up and are light enough for one person to unroll and attach to a roof with bolt-down straps. Designed to be installed by homeowners like me who hate to do plumbing, the Hot2O system is plumbed with PEX tubing and simple connectors.

Here’s how the basic Hot2O system works: A preset timer powers the circulation module, which sends water up through the roof panels to be heated. The water heated by the sun then returns to the circulation module, where its heat energy is transferred to a separate loop running between the circulation module and a coaxial adapter that hooks up to the drain valve of your existing water heater. The two closed loops of water circulate continuously for as long as the system is on, regardless of whether hot water is being used. When the circulation module turns off, all the water in the roof panels flows back down to a wall-mounted drain-back tank. As long as the drain-back tank is kept in a warm spot (above 32°F), the exterior pipes are never in danger of freezing.

The Hot2O system is also available in an upgraded Revolution version ($3900), which has 72 sq. ft. of panel and replaces the timer with an outdoor sensor that activates the circulation module when sunlight is sufficient to begin heating. You can also add this sensor to the standard system for about $300. Both of the systems qualify for the available 30% federal tax credit and might qualify for state tax credits as well.