In a previous Renewable Section we discussed the difference between a thermosyphon, also known as solar hot water roof mounted system, and a forced circulation system, or solar hot water slip system.

A thermosyphon is when the solar collectors are situated on the roof structure, facing south. The sun heats the water in the collector, which then goes into a tank. The hot water rises naturally in the tank, only then is the water made available to the house, either through a gravity feed or a pump.

A forced circulation system consists of south facing roof mounted collectors and a separate tank on the ground, usually located close to one of the major hot water consumption areas (such as the bathroom).

At Casa Verde we can create the perfect system, considering your needs and taking into account the number of people who are in the house. Get a system especially tailored, for your home and your hot water consumption rates.

How do they compare? Well, the energy benefits of both systems are about the same. While the heat loss is less in the forced circulation system as the tank is not as exposed to the elements as the thermosyphon, on top of the roof, some additional energy is necessary to operate the low wattage pump in the forced circulation system.

Which one should you choose then? This decision comes back to structural design of the roof, personal preference, water consumption and ease of access for servicing.

This system allows you to:

  • Enjoy FREE energy from the sun;
  • Protect yourself from rising energy costs;
  • Save up to 75% on your water heating bills (this system can provide up to 75% of your hot water for free using the sun’s energy and without using electricity or generating greenhouse gas emissions);
  • Access reliable hot water 24/7;
  • Decrease your household’s carbon footprint;
  • Increase the value of your property.

It’s important to choose the right system, including the solar collectors and tanks, which provides minimum thermal losses. When choosing the right deposit, you should also look at the thickness and the material of the tank’s walls.

For example, in a single-storey home, only with stairs to the basement, where four people live. This is a home with an open concept where the kitchen is connected to both the living and dining room, a pantry, 3 bedrooms and 1 bathroom. In this home since the homeowner stated his wish to keep the water deposit, of 300L, in the pantry, as this division is between the kitchen and the bathroom. In this case we suggest a forced circulation system, where the 2 solar panels, enough to generate power, will be mounted in the rooftop and connected to the water deposit. This system will allow the family to use their hot water to cover their necessities without a problem, using FREE energy.

More Energy Production Per Square Metre

If you’re worried about the space on your roof don’t be, this system doesn’t require as much space as you would imagine. Solar hot water systems need even less space than photovoltaic solar panels.

Casa Verde works with equipment that is developed under the strictest quality standards. With systems with a life expectancy of approximately 15 years, Casa Verde delivers the best installation while providing a simple and reliable operation. Our systems can also be integrated with existing heating systems (boilers, water heaters, including the swimming pool and/or underfloor heating).

Our system obtains solar energy to produce domestic hot water in the simplest and most economical way. They are ideal for supplying a family’s needs, and offer an eco-friendly alternative.

Just to give you an idea:

  • Cost of hot water in Portugal, in a year = 240€ per 120 cubic meters of consumption*
  • What you can save, in a year = up to 80% of that value

*On average, but consider that the price of water per cubic meter is a bit different between cities in Portugal, also this number is designed for a single person living alone in a house. This value doesn’t include the cost of sanitation or municipal solid waste.

Let our specialised team help you benefit from the energy of the sun, its FREE. Casa Verde are available to help advice and give you the best options for your home.

This system will allow you to not worry about other costs, such as gas or electricity bills (for example, if you have an electric hot water heater) to provide your homes’ hot water.

To find out more or BOOK your FREE assessment visit For more information contact us on:

+351 289 012 373 or +351 967 946 216