Heating and cooling systems

In general, reasonably detailed information is available on the types of building ser-vices used for heating and domestic hot water. Percentages or estimates of the pene-tration of techniques are given. Aspects that are taken into consideration here are heating and cooling systems, domestic hot water installations and ventilation systems.

Figure 4.10 shows the share of different heating systems for single-family dwellings and multi-family dwellings. In single-family dwellings, central heating based either on fossil fuel or on biomass is predominant. District heating is used mainly in multi-family dwellings. Local heating (stoves) still represents 5% to 17% of heating systems in Austria, Germany, the Netherlands and Switzerland. Local heating is mostly less efficient than central heating, but if installed only in one room, it often consumes less energy than central heating. In Swiss single-family dwellings, heat pumps already rep-resent 5% of the total heating systems. Electrical heating is widely used in Finland and France with shares up to 30%. Although one could argue that the direct use of electricity (without the additional use of a heat pump) for heating applications may be

sustainable if the electricity production is sustainable, from the point of view of ra-tionally using energy sources it would be better to use electricity only for applications where it is really necessary, as for the generation of mechanical work or lighting. Fur-thermore, nuclear energy is (partly) used in both countries to produce electricity, and except for CO2 emissions, the environmental friendliness of nuclear energy is doubt-ful. In terms of rational energy use, the use of relatively low temperature waste heat, as in district heating, is the most sustainable.

The efficiency of the different systems in terms of the ratio of the energy produced by the primary energy input may be assumed as indicated below.

Central heating: 0.75 for conventional boiler, 0.8 for increased efficiency boiler and 1.07 for high efficiency (condensing) boiler

Electrical heating: 0.4-0.7 depending on the efficiency of the electricity gen-eration in the region.

Local heating: 0.6-0.7

Collective heating: equivalent to central heating

District heating: theoretically infinitely high if based on waste heat from power plant or industry.

Heat pumps: 0.8-3 depending on COP heat pump and efficiency of electricity generation.

Active solar heating: not relevant because a renewable source is used

Types of space heating systems

0 Central heating (fossil fuel or biomass)

Single-family Multi-family

All dwellings

1 Austria: GWZ 2001

2 Finland: Ekorem report

3 France: Les Chiffres clés du batiment, Energie-Environnement, 2006, ADEME.

4 Germany: IWU estimates based on micro census 2002

5 Netherlands:SenterNovem, KWR 2002 and Basisrapport Kwalit. Woningregistratie 2000 (VROM).

6 Sweden: Sveriges Officiella Statistik

7 Switzerland: BFS

8 United Kingdom: CAR Ltd estimates and Energy Consumption in the UK (DTI)

Figure 4.10: Types of space heat-ing systems used in each country

Data for cooling systems were not available. Although the energy used for cooling is still very low in the residential sector, there seems to be a trend to install cooling in new dwellings to avoid super heating during the warm months.

Austria

The data for Austria were obtained from GWZ 2001. 80% of single-family houses have central heating with radiators. Of these, 78% use a gas, oil or coal boiler. In new single-family buildings, high efficiency gas or oil boilers are used. In multi- family houses, they account for half of all boilers. About 12% is central heating with wood or biomass and 6% is electric heating, principally used in the pre-1945 building stock.

In multi- family dwellings, individual central heating is employed in 52% of dwellings and collective central heating in 25% of dwellings. Collective central heating is more than 96% reliant on coal, gas or oil and half of this is a high efficiency system. Indi-vidual central heating is 71% reliant on gas, oil or coal and half of this is high effi-ciency.

17% of single-family houses use local heating (stoves) for heating, mainly in buildings built before 1960. Of these 71% are wood or biomass driven, 24% are coal, oil or gas driven, and 5% are electrical stoves. In multi-family dwellings, local heating is used in only 2.5% of the stock.

District heating is used in 2% of single-family dwellings, mostly post-1960, but in 21% of multi-family dwellings. Active solar heating is employed in only 1% of single-family dwellings and in 0.2% of multi-single-family dwellings.

Less than 5% of the total dwelling stock uses local air conditioners, but this number is rising. In 2007, around 1400 single-family houses and 240 multi-family houses had been built according to the principle of the passive house.

Finland

The Ekorem report gives aggregated data for space heating and tap water heating.

There is no breakdown in building services but there is for type of energy consumed.

In single-family houses, 32% of the energy used for heating comes from oil and 29%

from solid fuels (like coal). It is unknown if this energy is consumed by local heaters or by central heating. In Figure 4.10, it is assumed to be central heating. Solid fuels are used only in terraced houses, not in detached houses. Electrical heating is respon-sible for 29% of the energy used and district heating for 10%.

In multi-family dwellings, the energy consumption for heating is 80% from district heating and 20% from oil, which is assumed to be for central heating in Figure 3.17.

France

The reports “Les Chiffres clés du bâtiment” (ADEME) and “Le parc des logements existants” (CSTB) give the following data: in 24% of single-family dwellings and in 22% of multi-family dwellings, electrical central heating is the main heating source. In single-family houses, 36% of these electrically heated dwellings are found in the building stock built before 1975 and 64% in the post-1965 stock. In multi-family dwellings, these shares are 47 and 53% respectively.

Central heating (not electrical) is used in 76% of single-family houses. Collective cen-tral heating is employed in 34% of multi-family dwellings and individual cencen-tral heat-ing in 44%. For individual central heatheat-ing in the total dwellheat-ing stock, data from 2000

indicate that 22% of boilers are more than 20 years old, 67% are less than 14 years and 53% are less than 9 years old.

Germany

The data for Germany are based on a mix of quantitative data and estimates. Central heating with gas or oil is utilised in approximately 85% of single-family dwellings, electrical heating in 5%, district heating in 3% and local stoves with gas, oil, coal or biomass in 6%. For multi-family dwellings, the figures are 69% for gas or oil central heating, 3% for electrical heating, 23% for district heating and 5% for local stoves.

On average boilers and stoves are replaced every 20 years and piping every 40 years.

Netherlands

Data are available from SenterNovem, KWR 2002 and Basisrapportage Kwalitatieve Woningregistratie 2000 (VROM).In 2004, 82% of all dwellings had central heating, mostly gas-driven. Of these, 12% had a conventional boiler, 49% have an increased efficiency boiler and 39% a high efficiency condensing boiler. In addition to this, 30 939 heat pumps have been installed since 1990. This is less than 0.5% of all central heating systems.

Local stoves are found in 8% of dwellings, mostly gas-driven or using biomass. Bio-mass local heating accounts for 6.5% of the renewable energy use in the Netherlands.

Collective central heating is employed in 6% of dwellings and district heating is used in 4% of dwellings. District heating by biomass accounts for 33% of renewable en-ergy use, and district heating by waste heat for 15%. Active solar heating accounts for 1.5% of the Dutch renewable energy use.

Sweden

According to data from Sveriges Officiella Statistik 2005, 69% of all dwellings are connected to a district heating system, 4% are heated electrically, 4% have central heating with an oil boiler, and 2% have oil stoves. For 17% the type of heating is un-known.

Switzerland

The data come from BFS. 59% of single-family dwellings are equipped with a gas, oil or coal central heating system. 14% use central heating driven by wood or biomass and 13% use electrical central heating. District heating accounts for 2% and heat pumps for 5%, which is an unusual situation within Europe. Local oil, coal or gas stoves are used in 6% of single-family dwellings and local heating with wood or bio-mass in 1%.

65% of multi-family dwellings are equipped with a gas or oil central heating system.

8% use central heating driven by wood or biomass and 8% use electrical central heat-ing. District heating accounts for 3% of systems, heat pumps for 2%. Local oil or gas stoves are used in 14% of multi-family dwellings and local heating with wood or bio-mass in 1%.

United Kingdom

From estimates based on the report Energy Consumption in the UK, DTI, it seems probable that 88% of the total dwelling stock has central heating which uses gas or oil; oil being mainly restricted to rural areas. 7% of the stock has electric storage heaters.