How to make a homemade solar heater

The purpose of this project is to understand how the resources of solar water heaters work, which are so efficient and are already being exploited commercially, I will briefly explain why it works, and how to do it at home, how to take advantage of a resource as good and as free as C’est le soleil, and how to make it yourself little by little at home and comfortably, learning DIY, and without having to pay such a high price even if the performance is a little lower than those offered by the industrial prototype.

We must first understand what a solar collector does, and how it does it, to heat large capacities of water to such a high temperature and in a short time, because that is what it consists of, heating lots of water very quickly.

All commercial and domestic solar water heaters seek the same function, to accumulate a lot of heat inside a box (collector), and when said box is very hot, to run the water from our tank inside of this box, at the same time As the water passes through the box and heats up (and returns to the already heated tank), the box inevitably becomes cold, and when the box is already cold or not very hot, we will stop this flow of water until it gets very hot. to repeat the previous operation until the box stops heating (because the sun is already gone), with this we want to heat the water in our tank to the highest possible temperature.

All solar heaters, both commercial and household, consist of 3 parts to achieve the purposes described above:

  1. The collector: The most important element, the one that heats the heat transfer fluid or the water itself.
  2. Engine’: Who can be a water pump that moves flow at the right time and strategically, or we can do without that “ engine ” if we mount the manifold and tank the right way so that physics takes care of it. automatically move this flow.
  3. The deposit: No less important element, it must be correctly assembled and prepared, and properly insulated. A poorly insulated tank will ruin our entire assembly and cause our water to heat very little and cool quickly.

The efficiency of our solar water heater will depend on the materials used in the collector and its insulation, and the insulation of the water tank, there are very few trade secrets that benefit from a little more performance, but you can practically do it 100% at home and with perfectly comparable performance.

The collector This is usually a route normally made of metal tubes, it is also possible to use heat resistant plastics such as PVC or polyethylene, but with plastics the system is much less efficient. The tube material mentioned which will give us the best performance will be copper or aluminum, even stainless steel could be useful, although with less performance and with possible long term oxidation problems.

Engine, if we choose one Water pump The assembly will be a little more complicated, but if you do it well it will be worth it since the direct and indirect solar radiation is much better used.

The electrical consumption of the entire system (differential thermostat and water pump assembly) is generally very very low, between 5w and 20w depending on the pump, and if it is managed by the differential thermostat, consumption will be in short discontinuous cycles, à Throughout the day we will have consumed very little electricity in exchange for heating 100 or 200 liters of water.

No engine, says thermosiphon, is done by placing the tank on top of the collector and respecting specific measurements and distances, it happens that the physics makes the hot water (which weighs less) flow upwards and the cold water (weighs more) to submerge itself downwards, this automatic mechanism Of nature and the thermosiphon-shaped assembly, the hottest water always goes to the tank, and in exchange for a part of the less hot water from the tank moves towards the collector, you will find this very detailed information on many sites included in the wikipedia.

I chose to do it with a water pump (forced circulation) and I will base the whole project on that (but you can follow the same instructions by skipping the part you throw). For 2 simple reasons:

– 1, this gives you great freedom to locate where the manifold and the tank suit us best, although it is always advisable that they are as close to each other to avoid heat loss in waterways, and in our case we’re going to put it nearby so we can use a cheap, low-power water pump.

– 2, because the performance is much higher.

For complete manufacturing instructions, visit the web: