Passive House – a low-energy-house

Passive House – a low-energy-house

Did you go to court because of last winter’s heating costs?

This was just the beginning – analysts say that electricity prices will rise by 40% in 2013. All over the world more and more raw materials are used, fuel included and the slope is getting steeper. Swedbank estimates that housing costs will rise by 18.8% in the households.
A passive house is a very good insulated house, which nearly has the same temperature the whole year and fresh air. Walls, wind resistant windows and doors are especially built for passive houses to make them not affected by outsides temperatures. Fresh air ventilation is connected with heat recovery.
A general introduction video about passive houses can be seen here (in English)
Passive houses don’t need active heating systems. They use passive heating systems, which obtain energy from the sun, from heat sources and out of in the house located heat recovery systems.

How to prove the authenticity of a passive house or a low-energy-house?
• The buildings heat consume is maximum between 15 – 30 kWh/ m2 per year
• The heating system must have a capacity up to 10 W/ m2 per year
• The total amount of energy consumption (including heating, warm water and electricity) has to be below 120 kWh/ m2 per year.
• Effective ventilation system with heat recovery of 90% or more

What are the advantages of an energy-efficient low-energy-house?
• Low bills for electricity, heating and warm water
• Healthy climate in the inside
• Reliable products of leading manufactures
• Quick installation because of different modules
• Competitive prices

Reasons for deciding to build a passive house:

• Passive heating systems enable houses to refuse active heating systems and use passive ones instead, which obtain their energy from the sun, heat sources and from the house internal heat recovery.

• Passive- or thermal-module-quality – the passive-house-standard was developed by an institute in Darmstadt. There also was built the first passive house in Europe in 1980. American efficient-energy-houses use the so called “green-house”-standard, which doesn’t reach the quality of a passive house.
Passive houses in Europe show the current energy-efficiency-standard. Mainly in Germany, Austria and in Sweden schools are located, which dealt with the theory and the construction of passive houses over the last 15 – 20 years. The title “passive house” is the criteria of heat demand on primary energy between 15 kWh / m2 and 120 kWh / m2.

• Energy efficiency is based on very good heat insulation (foundation, walls, ceilings / roof) and the results of such buildings are thermal and air bridges. Used are also solar energy and geothermal heat. Even in winter, 1.5 m below the surface the temperature is still 4.5 degrees Celsius, similar to lakes or groundwater. You have to make sure, that the buildings heat insulation not allows losing more than 1 degree in 7 hours at outside temperatures between -20 to +20 degrees.

• The building can also be used to serve as heat source for a heat pump. A heat pump is basically working like a refrigerator but in reverse. A refrigerator produces cold, but to the wall behind it exudes heat. Heat pumps produce warmth by a high degree of energy concentration of lower energy surface (geothermic in the garden, warmth of the groundwater, energy fountain).

• There is a fast development because of the air-to-air- and air-to-water-heat-pumps, which gain their energy by air from the outside. The pumps process a huge amount of air from the outside. The colder it is, the bigger the amount of air which is pumped through the pump.

• The building is placed on a property with the opportunity to use solar energy, for that the building must be orientated from north to south.

• Passive heat elements inside the building are part of the planning of the internal energy, similar to the thermal power, like TVs, computer displays and people themselves are using. A person submits in average 40 – 80 W to his/hers surrounding, the room, which is comparable to the submitted energy of a 100 W bulb.

• By designing energy efficient houses, you have to calculate the thermal conductivity of the walls, than you have to choose a heat exchanger und finally a heat pump can be added. You also should know that you have to remember by renovating walls or to build a new house that a reduction of heat transfer of forced ventilation is created or a heat exchanger has to be installed.

• In the last 15 years the market for passive buildings has increased in average by 25 – 75 % each year. Usually it takes days or weeks to sell a passive house, because you have to erase all the doubts of clients by patiently explaining the technique and the details. An effective method has become, to rent a passive house to the clients for a few days up to one week. They get used to the comforts of a passive house very quick.

• The design of the building is laid out for the energy calculation program PHPP 2007. Therefore heat conductivity of foundation, walls and ceilings are used, just as the openness towards south and the layout of the property, to calculate which heat energy is needed. It is important to use a heat exchanger, than a heat pump can complement the needed heat energy.
During the erecting time the building has to pass a pressure test, before finishing the works. In the sealed building (closed doors and Windows to the outside) an overpressure of 50 Pascal is created and the pump is only allowed to work 0,6 time per hour.
The windows of a passive house can be opened but there is no certain need. The house can have a fireplace, but you should pay attention on overheating.
Wolf Thermo Module Europe Ltd. is a company with a growth between 25 to 75 % each year over the past 15 years. This year about 850 houses will be built. The thermo-module-neopor-product is made for floor-, wall- and roof-elements to find a constructive solution for form and insulation. This is a monolithic construction, without frost and air bridges. The Passive House Institute in Darmstadt has researched this technology and placed a certificate, which proves, that the technology delivers 15 kWh / m2 because of the building’s design.

• The thermo-module of a passive construction is a professional solution. For 15 years the Passive House Institute Darmstadt guaranties this quality.

Here you can watch a 21:40 minutes clip as introduction for passive houses. This clip is about a passive house built by the company Kanal2 Kodusaatest in Jõelähtme:
http://kanal2.ee/vaatasaateid/Kodusaade?videoid=2311