PV Gap

Kelly Said:

What should water temperature be during no sunlight periods, using a solar/electric water heater?

We Answered:

I would think it needs to be turned down. They recommend a maximum 125 to prevent scalding.

I have only worked on a few solar systems but they all used a "regular" water heater to supplement the heat and store the warmed water. They were just plumbed differently.

Usually they were set lower and on all the time. Lower so they did not try to heat the water going through the solar panels.

But it is near impossible for us to tell you how yours is set up, the logic of the system. We know nothing about it, how it is plumbed, what controls, even how it works normally.

I don't know if you have two tanks or one and the single tank is for both storage and heating.

The main reason people turn up the temp is if the water is hotter you use less. So at 140 you might get three showers first thing in the morning, but at 125 degrees maybe only two without time in between heating water.

I say try it. I can't think of any reason lowering the temp would be a problem, except for capacity as mentioned.

Good Luck.

Lauren Said:

Did you make solar water heater in home, are you satisfied with its working?

We Answered:

I have a solar water heater system that I installed at my house. it works year round. In the winter it can provide about half of my hot water, in the summer, all of it.

You can buy kits that have most of the components to install, or you can build your own collectors as well, although they may not work as well or for long as factory built ones.

http://www.altestore.com/store/Solar-Wat…
http://www.builditsolar.com/Projects/Wat…

Jamie Said:

does any one know where i can get free plans to make a solar water heater?

We Answered:

I very much doubt that this is possible.

The plans are probably confidential and/or you may have to pay to use them, even for private use.

Good luck trying!

Ricky Said:

How efficient is solar water heater?

We Answered:

depends on the sun.
and the storage you have.
and the amount of hot water you use.
and the insulation.

i don't know either.
clearly they could claim "the average user saves ????", and you couldn't check.
however, a hot shower is quite a luxury, so it's probably a good investment.

if you were really interested, you could probably do a reasonable calculation.
you're not using the furnace, so it's only cooking and hot water.
you could fill a bucket and time it, and calculate how much water you use.
i'm sure someone at the gas company could tell you how much gas it would take to heat that.
keep in mind, in the winter, when it's harder to calculate because of the furnace, the water comes into the house colder, and so is more expensive to heat.

Cheryl Said:

why does a solar water heater have coiled pipes ?

We Answered:

Coiling allows one to put more pipe into a smaller space. And the more pipe there is, the more pipe area there is exposed to the sunlight. All other things equal, more heat is transferred across the pipe when more of its area is exposed. Naturally, the more heat transferred across the pipe and into the water, the hotter the contained water will become.

Bottom line, the pipes are coiled to make the water hotter by exposing more pipe to the sunlight.