Building a NuTech Passive Solar House® can save you €25,000

 

NuTech has specialised in designing and building Low Energy Houses for the past 25 years.

 

The passive house concept has become a European wide accepted solution to reach a significant energy demand reduction in the built environment.

 

In a typical modern house, built to the 2006 Building Regulations, the energy use for Space Heating, Ventilation and Hot Water is broken down to three thirds as follows:

 

Ø      The first third is due to energy / heat loss through the fabric of the house i.e. the heat loss through the walls, floor, roof and windows

 

Ø      The second third is due to air infiltration and the necessary air for ventilation. Note: It is of equal importance as the insulation and expensive glazing in a house

 

Ø      The final third is due to energy required for Domestic Hot Water

 

 

 

 

The energy use in this modern house is considerably more than would be required in a Passive House or a NuTech Passive Solar House as shown in Figure 1.

  

 

In designing a Passive House in Ireland we must take into account the differences in Temperatures throughout Europe. Ireland has approximately the same climate as Rennes in France in Figure 2.

 

 

The NuTech Passive Solar House concept deals with these three items, as mentioned above in the following way:

 

Ø      The house is very highly insulated and has much reduced Thermal Bridging

 

Ø      The house is constructed to be very airtight thereby reducing unwanted cold air infiltration to a minimum. In order to ensure that the house has controlled amounts of fresh air it is ventilated by an efficient Heat Recovery Ventilation system.

 

Ø      The house is orientated to make best use of solar gains through the windows.

 

By these means the heat losses are so reduced that it does not require a conventional heating system to heat the house. NuTech uses the slightly oversized HRV system as the means to supply heat to the house when required.

 

The key to success for any Passive House is to reduce the Energy Demand to a minimum

 

A vitally important part of the NuTech Passive Solar House concept is that energy from the slightly larger Solar Array is used for both Solar Hot Water and for Solar Space Heating. It is a fully integrated system controlled by NuTech's electronic IRES controller.

 

   

The Technical Targets for typical Passive Houses are as follows:

 

Ø      The Annual Delivered Energy used for Space Heating should be less than 15 kWh/m2.year

 

Ø      The Specific Annual Heating Load should be less than 10 W/m2

 

Ø      The Air Infiltration level is less than or equal to 0.6 Air Changes per Hour (ACH) at 50 Pa as measured by a Blower Door test

 

Note: The Specific Annual Heating Load is calculated in a very specific way in the PHPP Package. It takes account of solar gains through the windows and occupancy gains also.

 

These above Targets are very onerous but they can be relaxed in the NuTech Passive Solar House design to the following but they must be strictly adhered to:

 

Ø      U Ext Wall is less than or equal to 0.16 W/m2.K

 

Ø      U Ground Floor is less than or equal to 0.15 W/m2.K

 

Ø      U Roof is less than or equal to 0.12 W/m2.K

 

Ø      U Window is less than or equal to 1.20 W/m2.K

 

Ø      The air infiltration level is less than or equal to 1.0 Air Changes per Hour (ACH) at 50Pa as measured by a Blower Door test

 

Ø      The house utilizes solar gains through windows facing from South-East through to South-West

 

Ø      A solar array of at least 6m2 of evacuated tube collector which is integrated by way of the NuTech IRES system thereby feeding energy to both the space and water heating system. The required area will depend on the floor area of the house

 

Ø      All components used must be certified or approved by NuTech

 

 

Benefits of a designed NuTech Passive Solar House

 

The major benefits of the NuTech Passive Solar House are as follows:

 

Ø      The Energy Demand for both Space and Water Heating are reduced to an economic minimum. This means that the running costs for space and water heating are minimised.

 

Ø      The controlled ventilation by way of the Heat Recovery Ventilation system gives rise to a comfortable, healthy house without draughts or condensation or mould growth

 

 

Further Information

  Please contact NuTech Renewables Ltd for further Information