PV Gap

Dennis Said:

Is solar water heater cost effective?

We Answered:

I have often thought about building a pre-heater to assist my electric heater and cut down on costs. They will only work in certain locations with lots of sunshine and may be unattractive depending on where they are placed.
You can build one with a metal tank with a pipe fitting on each end. Build a three sided box that the tank will fit into with glass on one side. Paint the tank and inside of the box flat black. The box is positioned so the the glass side is exposed to maximum sunlight. Connect a water supply to one side of the tank and run a pipe from the other side to the cold water supply of the gas or electric water heater. The water coming into the gas heater will be pre-warmed. Just something I think would be interesting to try. Good Luck.

Lauren Said:

Does solar water heater work in monsoon?

We Answered:

If you live in a warm climate you can almost certainly save money with a solar water heater. Even if it doesn't work every day, it will save money. What you can do is have the solar feed the tank of a conventional water heater. If there are even a few hours of sun in a day, that is enough to completely heat the water. My observation of my brother's house in Hawaii is that the conventional heater only turns on a few times a year, when there are multiple dark days in a row.

The best data will come from your neighbors locally. Walk around the neighborhood until you see someone with a solar water heater, then ask them how well it works during monsoon.

Melinda Said:

How to make reflective solar water heater?

We Answered:

There are several different ways. First you need to decide if you are going to use a flat reflective surface or a parabolic reflective surface.

Probably the easiest way is to get an old tv dish antenna (the small ones not a 10' huge one) and make the surface reflective. You might try gluing aluminum foil on the inside. Add up your surface area and then put that much water at the focal point. This dish will have to remain pointed at the sun to work best.

Another way is to make a parabolic trough reflector. The water will be in a long pipe suspended at the focal point of a trough that is reflective. For this one it is enough to have the trough pointed east-west and tilted at the correct angle for the sun at this time of year. You might use aluminum flashing for the trough.

You could use flat mirrors that will be focused on the container. Because they are not curved they will not focus as well as a curved mirror but with enough mirrors it will still work.

Melinda Said:

can a solar water heater be hooked with a tankless water system?

We Answered:

you could have a 2 panel 80 gallon tank solar thermal system backed up by a tankless. but if you have a tankless, you dont need anything else, it wont work with solar panels, you must have a storage tank. if you have the money, do it. (roughly $10,000) installed with a heating element in your air handler to pre heat your air in the winter. payback around 5 years pending tax credits. if thats to complicated, just do tankless, they are awesome. do both if you have the dough. your neighbors will be jealous.

Tiffany Said:

Selecting a gas to fill a homemade solar water heater?

We Answered:

Thermal mass (also called heat capacity) is the capacity of a body to store heat. There are two varieties of the heat capacity Cp and Cv where Cp is ate constant pressure and Cv is at constant volume, the higher the heat capacity the more heat the substance may retain, Hydrogen has a very high heat capacity 10.16 kJ/kg*K, though it may be a bit dangerous, the next could be Nitrogen tetroxide at 4.6 kJ/kg*K, the heat capacity is a function of temperature, and will vary as the temperature changes.

http://www.engineeringtoolbox.com/spesif…

Monica Said:

How can I fix a leak in my pool's solar water heater?

We Answered:

Is the leak in the panel or the lines to the panel?
The lines to the panel are the easy fix. Just cut the line remove any sharp edges and install a "shark bite" type of fitting per the instructions.

The panel is a little more difficult. If the tubing has movement ( only one end attached ) repair as above. If both ends are secured clean the hole with a fine wire brush or steel wool, drill a small hole, and fill with a two-part epoxy made for metal.