Passive solar greenhouse: get an early start
Thermitube can be used to convert a conventional greenhouse into a passive solar greenhouse or bioclimatic greenhouse. Market gardeners, horticulturists, nurserymen and arboriculturists producing under glass can:
- gain in precocity
- extend the autumn season
- improve health
- increase yields without heating
- keep their greenhouses frost-free.
ThermiTube consists of a flexible black tube filled with water. The tubes are placed between the rows of plants or under the shelves. The bioclimatic greenhouse system works like a horizontal hydro-accumulator: it passively captures solar heat during the day and releases it at night. This heat is released mainly by radiation, which means that the plants are heated rather than the entire volume of the greenhouse.
ThermiTube can be installed in all types of greenhouses, existing or new, whatever the size and orientation. The innovative system requires no maintenance and no running costs. In a greenhouse heated to 12°C, the Thermitube can reduce energy consumption by 50%. pass
A simple, robust passive solar greenhouse system for growers
The cost of installation of the passive solar greenhouse is adapted to the investment capacity of growers. The cost is around €12/ml for a 25 cm diameter. The Thermitube has a lifetime of between 7 and 10 years and a payback on investment of between 2 and 5 years.
Agrithermic and ASTREDHOR developed and tested the Thermitube. CTIFL has written a CEE form for bioclimatic greenhouses and shelters with hydro-accumulation, enabling farms to finance their investment.
We also offer other types of bioclimatic greenhouses, solar greenhouses and various renewable energy heating systems.
How do I install the Thermitube in a passive solar greenhouse?
To facilitate the installation of the Thermitube in passive solar greenhouses, this video shows how to install the Thermitube at the start of the season and how to store it after the harvest.
How does the ThermiTube work in your passive solar greenhouse?
The ThermiTube works like a passive solar greenhouse or bioclimatic greenhouse.
– During the day it stocks solar energy by direct radiation (1) and by convection (2).
– It releases this energy at night or during cloudy periods (4) by convection to heat the air in the greenhouse (3) and by radiation to heat the leaves directly (4).
– It also heats the ground by conduction (5).
– The greenhouse is insulated to reduce heat loss (6).
The system requires no solar panels or external heating.
Climate and technology in Thermitube in passive solar greenhouse
On cold nights, the sky is clear and the weather has generally been fine the previous day. The need for heating is high, but the greenhouse will have accumulated a large amount of energy.
It is unusual for it to freeze on cloudy nights. If it was cloudy the previous day, the passive solar greenhouse will have stocked little heat, but that’s not a problem because heating requirements are low.
The difficulty comes when the day has been cloudy and the sky clears at the start of the night. In this case, the storage will have been sized at the design stage.