When designing and building a Passivhaus we use the PHPP software from The Passive House Institute. The goal is for the design and resulting construction to meet the Passivhaus criteria.
The house below is nearing construction in County Mayo where the design and construction has been modelled in PHPP, below that is the PHPP verification:
As well as meeting a consistent year-round internal temperature of 20°C; it is essential in this climate emergency that we also account for any possible overheating:
In 2003 the summer heatwave across Europe is estimated to have caused the deaths of more than 35,000 people, including 2000 in the UK (see 1). During that heatwave, Londoners experienced 12 consecutive days with temperatures peaking between 26 and 37˚C and, significantly, night temperatures staying above19˚C for 7 continuous nights. Excessive heat like this has known effects on health (see 2) particularly when combined with high levels of humidity. (Zero Carbon Hub)
And don’t think that Ireland will escape this; the image below from Passive House magazine (https://passivehouseplus.ie/magazine/insight/overheating-a-growing-threat-that-mustn-t-be-ignored) shows the temperature anomoly from 2006:
Image from: https://passivehouseplus.ie/magazine/insight/overheating-a-growing-threat-that-mustn-t-be-ignored
This is why Passivhaus PHPP has a verification for the number of days greater than 25°C (which needs to be less than 10%).
Now this is great but inspired by UK colleague Mark Siddall (architect & Passivhaus Designer), for this project we’re also going to do a little bit of empirical analysis which will involve setting up a data-logger to measure internal temperature and relative humidity for the year. We’re going to set this is the area most prone to overheating and diurnal swings (differences between maximum and minimum temperatures).
Below is the logger that we’re going to use; this has a display so that the clients can keep an eye on the temperature too:
As well as empirically seeing if the internal temperature hits the 20°C, we’ll also analyse the year to get the percentage >25°C (PHPP (see above) has this at zero).
If I can get hold of the heating bills for the year; I’ll also try to correlate the costs against the heating demand.
Construction by Longlife Structures
So, watch this space…
Comments welcome…