Solar Water Heater with a Tankless Water Heater?

I was asked by a potential customer a few days ago about using a solar water heater in conjunction with a tankless water heater.  I think using a solar water heater to feed a tankless water heater is a great idea and a green idea at that.

Solar water heaters come in a variety of types. Some are passive and do not require a pump, some do require one or more pumps, some directly heat the potable water, and some use indirect means to heat the potable water. 

The passive solar systems sometimes locate a storage tank above the solar panels, that way the hot water rises into the storage tank, and cooler water from the tank sinks down to the bottom of the collectors.  This thermo siphon cycle continues as long as the water in the collectors is being heated.

Passive batch solar water heaters have an insulated enclosure faced with glass or transparent plastic and filled with tubes or cylinders or even a tank that absorb the suns rays and heat the water in a batch.  No circulating needed.

In active type solar systems a pump circulates the water from the collectors into the storage tank when the temperature in the collectors is sufficiently high and above the temperature in the tank.  Some systems use an indirect method of heating the water.  These indirect systems circulate a fluid through the solar collectors and then through a heat exchanger in the hot water tank.

Solar hot water tanks are very well insulated, and they do not have a flue through the center, so they have minimal standby losses.

The choice of which type of system to use would include your geographical location since some parts of the world have substantially more sunshine, and if you are in an area where the temperature drops below freezing you need to take that into account as well.

Tankless water heaters modulate the gas burners or electric heating elements to maintain a steady pre-set outlet temperature.  If you feed the inlet with the outlet from your solar water heater the tankless unit will not turn on unless the water temperature coming from the solar water hater isn’t hot enough, and if it isn’t, it will burn just enough gas or consume just enough current to keep the outlet temperature at the pre-set temperature.

You end up with a highly efficient hot water plumbing system that uses the minimum amount of energy when solar hot water is available, and you still have unlimited amounts of hot water when you need it.  It’s a great way to turn your residential plumbing system green.

Adding a hot water demand system makes the system even greener.  By adding the hot water demand pump you save water as well as energy.  A demand pump uses very little energy, typically about $2.00 per year in electricity costs, and saves many thousands of gallons of water per year.

By combining all three items, solar hot water heating, tankless hot water heater, and a hot water demand system you get the greenest possible solution to your hot water problems, providing you with water savings, energy savings, and the convenience of fast and endless hot water.  You reduce green house gas emissions, reduce your carbon foot print and save money.

Hot Water – Water Heating Best Brand of Tankless Water Heater

Going Green – Hot water conservation Solar Water Heater – Tankless Water Heater

Water heater recirc and circulation systems: Green Home Improvements – Saving Money

Article Source:http://www.articlesbase.com/diy-articles/solar-water-heater-with-a-tankless-water-heater-1636552.html