Thursday, April 22, 2010


Introduction to ecological heating and ventilation

This section presents various systems, which may be used for the heating and ventilation of an ecological house. Some systems can be used successfully in regular older houses as well; in particular the systems for “green” domestic water heating and ventilation, which could be installed in virtually any older building. We distinguish between space heating, i.e. heating of the rooms in the house, and tap-water heating, i.e. domestic hot water. (Solar collectors should heat the tap water in any house).More info at SOLAR SERDAR.

All houses need ventilation. In a super-insulated passive house, a ventilation system with heatrecovery is nessesary, as well as some means of heating tap water. We consider good ventilation essential in any type of house, however, it is difficult to achieve good energy performance without some form of reduction of the ventilation heat losses. This is why we recommend a minimum of three systems in any type of house:

* Ventilation with heat-recovery
* Space-heating
* Tap-water heating

Reduce the heat losses first. Please keep in mind that the amount of energy needed should be reduced as far as possible in the construction of the house. Secondly, the location and orientation of the house and the amount of hot-water usage will dictate which system to choose. The initial investment cost, the life-length and the complexity of the system must be considered both for economical reasons but also for ecological reasons.

KISS (keep it simple). Ideally the inhabitants of the house should be able to understand and maintain the system - otherwise it might not work at all - and that would not be very ecological!

Air-air heat pumps. For some strange reason these economical heat pumps are practically unheard of in Ireland and Britain. They give off 3-5 times the amount of energy used and they are cheap and quick to install. One drawback is that they only heat a local area, much the same as a stove. Works best with open plan.

Geothermal heatpumps. We are not covering the large type of heat-pump that connects to pipes in the ground. The electrical power consumption of such a geothermal heatpump is usually 2-3kW with an output of 6-12kW. We consider that to be oversized for most low-energy and all passive houses.

Wood pellets and wood chips. On these pages we are not covering this type of environmentally sound source of heat. The reason is that there is an abundance of information about wood-pellets, wood-chips and pellet-boilers from many other sources.

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