In selecting of a fuel, in addition to comfort requirements and local conditions, likewise the availability and environmental effects need to play a role. If you use a furnace, then it should be specialized in the fuel that you plan to use. Your HVAC specialist can assist you.

When you replace or update your heating system, do not forget that the chimney needs to be matched to the heating system (where old chimneys have a danger of condensate formation and sooting). In addition the chimney sweep must test the tightness of the chimney. Replace or modernize your heating system only after finishing the insulation of the building.

Solar and ambient heat

Solar collectors

The power of the sun is inexhaustible. This is a more than convincing argument for a solar system to support a conventional heating system. For well-insulated houses and low-temperature heating systems, collector surfaces of 20 – 50 m2 in combination with buffer tanks (1000 to 5000 liters) can yield overall coverage of 20 – 60% for heating and hot water. The prerequisite is good insulation. Note: The sun can also be used for passive heating, as in a winter garden.

Wann eine Solaranlage Sinn macht und wie groß sie dimensioniert sein sollte, beantworten Experten, wenn sie Ihre genauen Bedingungen kennen.

• When a solar system makes sense and how large it should be dimensioned can be explained by solar experts once they know your exact conditions.
• As a benchmark, per person in the household you need 1.5 m2 of collector surface and 100 liters of buffer tank volume.
• For a very well insulated low-energy house with a low-temperature heating system, the solar system can handle the task of heating.
• In Austria, for example, there is generally sufficient solar radiation to justify a solar system. Here the average value is 1100 kWh per square meter annually. Higher elevations even achieve values over 1400 kWh.
• Any roof surface that has no shade year-round and that does not diverge more than 45° from the south is principally suited for a solar system.
• Facades with southern exposure also serve well as solar collector surfaces.
• Even if the sun does not always shine, you need not settle for cold showers. What the sun cannot do is handled by the heating system.
• The installation of solar systems is subsidized in many areas. Ask for details at the housing subsidy authority for your locality or region.

Heat pumps

Heat pumps draw ambient energy from ground, water or air as stored solar energy for the purpose of heating and hot water.

• A heat pump contains a circulating coolant that draws ambient heat via evaporation and transfers this to the heating system via compression.
• Depending on the efficiency factor of the heat pump (consult an HVAC expert), one kWh of electric power used to drive the compressor will produce a multiple thereof as heat.
• This heating system is suitable especially for well insulated buildings with low-temperature heating systems.

Low-temperature and HHV furnaces

While conventional furnace designs avoid condensation of steam to prevent corrosion damage, HHV furnaces utilize the condensation heat of the steam contained in the combustion gas. Note: Chimney must be appropriate.

• Operation and standby temperatures for conventional furnaces are 60° C or more.
• A low-temperature furnace works with a heating system inlet temperature of only 40 – 50° C.
• Very low temperature furnaces are suited for even lower temperatures; thus they have less losses to exhaust gas and standby, so they require less energy.

Natural gas

Here HHV technology pays off particularly because more steam occurs in the combustion of natural gas than for other fuels. These are the conventional gas furnace types:

•  Blower furnace
• Atmospheric furnace
• Special furnace (very low exhaust emissions)
• Gas boiler (or combination hot water and heating), often used to heat individual apartments, heats according to the principle of a tankless water heater.

Oil

• Oil furnaces are normally equipped with oil blower forced-air oil burner, sometimes with a vaporizing burner.

Electricity

Few households today heat with electricity, usually in the form of a night-current storage system based on special nighttime electricity rates. Direct electrical heating as the main heating system in a new construction are usually no longer permissible. the following systems are common:

• storage heating systems
• electric convectors
• electric blowers and panels
• electric floor radiant heating and infrared radiant heaters, particularly for individual rooms (bath)
• electric central storage systems
• continuous-flow furnace for central heating systems
• heat pumps that require electric power for pumps and compressors and can generate 4 kWh of heat from 1 kWh of electric energy