L&M YOUNG LTD
Energy Efficient Solutions

INTRODUCTION TO A PASSIVE HOUSE

     
Definition: A dwelling that meets the following criteria is deemed to conform to Passive standard:

A dwelling that is so designed and constructed so as to meet the annual space heating requirement of 15 kWh/metre sq. per annum of treated floor area together with an upper limit for total / primary energy demand not exceeding 120 kWh mtr2 per annum regardless of energy source.

Interesting fact:

A passive dwelling does not need a conventional heating system as it sources the necessary space heat and DHW requirement from renewable resources and harnesses these gains by exact design coupled with optimum levels of insulation. A supplementary pellet stove is desirable.

In the early stages great importance is given to design, including site selection, orientation of building, size of construction / volume, floor area, and materials used. The Passive House Planning Package software is used to check, and recheck, for Passive House Standard compliance. Using this system provides an early indication of values being achieved.

U-Values of elements considerably surpass those set down in our current Building Regulations Part L.

Particular attention is paid to Draught – Proofing. This is achieved by the expert fitting of an air tight envelope inside the dwelling thus eliminating cold draughts and increasing thermal comfort. Air pressure tests are carried out on site during construction and an air permeability rating of 0.6 air changes per hour must be achieved at a certain pre defined pressure of 50 Pascal. If this rating is not achieved then remedial measures must be taken. Negative & positive pressure are applied.

Typical equipment used in the construction and fit out of a Passive dwelling includes:

1. Solar Thermal Collector. Contributes 60% of total DHW.
2. Heat Pump Technology.
3. Mechanical Heat Ventilation Recovery.
4. Wood Pellet. 80-90 % efficient.
5. Water to Air Heat Exchanger.
6. Photovoltaic.
7. Wind turbine.

Generally glazed areas face south to maximise heat solar gains.

As always great care by contractors during the course of construction is an absolute must.