Passive house

Definition A Passive house is a buildings with good comfort

conditions during winter and summer, without traditional space heating systems and without active cooling.

Typically this includes optimised insulation levels with minimal thermal

bridges very low air-leakage through the building utilisation of passive solar and internal gains good indoor air quality maintained by a mechanical

ventilation system with highly efficient heat recovery.

Building Energy Rating (BER) Certificate

Irish law states that when a building is constructed, rented or sold a Building Energy Rating (BER) certificate and label must be made available to prospective buyers or tenants. The BER is expressed in terms of KWh of primary energy/m2/year. A passive house has the potential to achieve an A2 or even an A1 rating

What an Assessor looks at • building structure • ventilation • heat losses • domestic hot water • internal heat gains • solar heat gains • mean internal temperature • space heat use • space heating requirements • total energy use • fuel costs • energy emissions and • costs.

To increase the BER...• Increasing the insulation in the walls/attic/floors• Installing advanced energy efficient windows/doors• Measures to achieve controlled, healthy ventilation• Replace an old or inefficient boiler with a more

efficient boiler• Installing modern heating controls

(timers/thermostats)• Installing certain types of renewable energy heating

systems (solar panels, wood pellet boilers, micro turbine)

• Insulating the hot water cylinder and pipe work.

What are the benefits of having a BER system?

• Increases awareness - making consumers more aware of the energy consumption of a dwelling they will choose to live in more energy efficient (and less costly) homes.

• Change behaviour - making people more aware of the energy performance of buildings will encourage them to conserve energy

• Encourage better design - architects/ builders/ developers will build more energy efficient homes to encourage people to make their houses more attractive to buyers.

• Fight climate change – improving the energy performance of homes will lower energy consumption and reduce CO2 emissions

1. Well insulated building envelope2. High energy performing windows and doors3. Minimised heat loss through thermal bridging4. Significantly reduced structural air infiltration5. Optimal use of passive solar and internal heat

gains

Membranes and specialist tapes are used to create an

airtight envelope. Thicker than normal wall sections are designed in order

to accommodate the required depth of insulation. The insulation at the junction of roof and wall, as well

as wall and floor overlap. Special blockwork with low thermal conductivity is

used in the rising walls A pellet stove for the backup space and water heating

system. Solar panels are positioned on the south facing roof

which is pitched at the optimal angle of 45 degrees. All windows in the house are triple glazed with low

emissivity coating, The hatch to the attic should be very well insulated

and completely airtight to minimise cold air infiltration.

Geo-Thermal heat systems

No matter how hot or cold it is on the surface, the ground a few meters down generally maintains a stable temperature.

Environmentally-friendly anti-freeze solution from the ground loop enters the heat pump and passes through a heat exchanger where latent heat energy is transferred to a refrigerant

A refrigerant carries the heat from one area to another.

When compressed, it is a high temperature, high-pressure liquid.

The compressor raises the temperature of the refrigerant to approximately 140 degrees Fahrenheit

If it is allowed to expand, it turns into a low temperature

pay back their installation costs in energy savings in 5-10 years.

The drawback to geothermal heat pumps is the fact that the unit requires some extensive digging in order to install.