Category Archives: Passive House Data

Current Performance (without air tightness and full insulation)

Temperature Recordings

I decided to record the temperature inside and outside in order to get a feel for how the house performs before it is finished.

The current state of the self build is  :

  • Two ceilings have an airtight membrane and one of the walls has a membrane (both are incomplete)
  • I still need to install another 50 mm of insulation on most of the internal walls (2 of the 8 walls have the 50 mm insulation.
  • Two windows are not sealed and all have no airtight membranes attached.
  • The lower windows are shaded by scaffolding (minimum solar gain at the moment)
  • The HRV inlet and outlet ducts are loosely taped over
  • The floor is concrete
  • The wall and glue-lam beam wood moisture level is 13.5%
  • There is no heating system
Passive House Temperature
Outside Temperature
Passive House Data Inside
Inside Temperature

I collected data over a similar time period to the above and the results were similar.

The Old Plan and the New Plan

The plan was to install another 100 mm of insulation on the internal walls but I have now decided to not do this based on the results above and adjustment of the PHPP (passive house planning package) software. I feel I have left enough of a safety margin in the PHPP to still attain the passive house standard. For example I left the ground level door and window installation thermal bridge psi values at the PHPP default .

Installing the extra insulation would cost €1500 and the wooden frame to hold it in place would have added another €2000 approximately (Savings €3500) . I also reviewed the ceiling voids as I had planned to allow a 100 mm service cavity for the HRV ductwork. This was on reflection going to cost an extra €3500 approximately but now I will be able to hide the ducts using a simpler localised approach (Saved another €3500). It is nice to be in a position to review the costs at the pace of our self build.

Data Logging and Monitoring

I am now researching an economical building performance monitoring and control system that will record and display data over a longer period of time and allow me to control certain functions such as entrance gates, lighting etc .  I have read that the actual performance of houses being built whether passive or standard do not always perform the way they were supposed to.

I feel the only way to monitor this is to have an economical simple system (easy to use ) that watches for failures and highlights issues during the life of the build.  When one reduces the energy levels to a very low level finding problems before they increase cost is a must. For example on a recent school project the storage heating contactor went faulty in the closed position which meant the storage heating was on day and night. One had to wait for the next ESB bill to find there was a problem. 

The items I want to record are:

  • temperature
  • humidity
  • AC current
  • CO2
  • Solar DC PV output
  • Solar Hot Water inputs and Outputs
  • Relay Outputs

I note that the american PHIUS (passive house breakaway group) which is the equivalent of the passive house institute in Germany have co-developed a building Monitoring solution starting at $800 with powerwisesystems.com . I feel this is still too expensive. Lets see what my research turns up.

More Temperature Data (Update)

Inside and Outside Temperature with scaffolding taken down and all doors and windows closed-Image Below

Temperature Performance Passive House

Inside and Outside Temperature with scaffolding still in place-Image Below.

Passive House Temperatures

 

 

 

 

Performance Standard -Setting the Standard

The passive house software allows one to set your own performance standard by selecting how much energy (oil/gas/electricity) one wants to use to heat the building.

For example current Irish house builds that comply with today’s standard 2014 are estimated to use 100watts per m2 (subjective). The passive house standard if one goes for certification uses 10w per m2 (objective).

The real benefit for using the PHPP software is that the performance approach can be set by the home user. For example if I want to reduce my energy consumption to 1.5 litres of oil per m2 of the house size then I can set the software to a maximum of 15kwh per m2 for the year while maintaining a temperature of 20 degrees Celsius.

In a typical 3 bedroom house with an area of 100m2 the oil usage would be 150 litres a year.  With the PHPP performance software one can set the number of litres of oil (or gas etc) per year that your residential or commercial property will use to within a small margin of error. In other words you select the performance value of your build.

In summary the PHPP software takes into account your comfort and health (temperature and oxygen levels)  by removing high CO2 levels and VOCs and providing an even temperature throughout the house.