John Straube

Building scientist. Farmer

[John Straube @jfstraube]

@BasedMikeLee It's not 100B but even so that would be a bargain for the damage done to a key US advesary. That it is the morally correct thing to do is hard to price but likely worth that much again.

[John Straube @jfstraube]

@JurajMikurcik @ArchitypeUK If it is warm outside overnight, thermal mass and night purging wont be enough to make up for even modest internal gains. External shades is the obvious big first step to reduce that heat gain. If this building were in a hot climate (25+ overnight), nothing would help it.

[John Straube @jfstraube]

@MontePaulsen @SoniaFurstenau @bcndp I completely agree Monte. Historically people suffered and died in cold weather… so the codes or regulations set a minimum acceptable temperature. As the climate changes we also need to set a max. This is not political just a common sense response to changing conditions

[Chris Higgins @CAHiggins]

Do you want to add exterior insulation to an existing home in Vancouver? I am pleased to report that Vancouver excludes the extra insulation from the floor area calculation. Bulletin: https://t.co/P9uZEu6O3p #retrofit

[John Straube @jfstraube]

@Chris__Parsons Looks good to me but you need to seal the rigid foam in an airtight manner to the edges of the rafters and the plaster of the wall below. The interior plasterboard is unlikely to provide a reliable air barrier. We have done lots of retrofits and repairs like this.

[John Straube @jfstraube]

@EnergyVanguard Yup, thats about as bad as it gets. The 20-40% effective is correct and applies to the value of the ci, not the whole wall. So for an R-10 XPS layer, expect about R2 to R4. likely close to R-2

[John Straube @jfstraube]

@MarkSiddallRIBA @EnergyVanguard @JohnSemmelhack I have been involved in numerous SIPS failures like this.

[John Straube @jfstraube]

@allisonbailes Best wishes for a speedy recovery -- your positive attitude will help with that I am sure! So many people benefit from your help. Get well soon and enjoy Christmas.

[John Straube @jfstraube]

@ArchTesta Interestingly in North America that would be a photo of a major deficiency… no gap behind veneer for ventilation and drainage, no defined water or air barrier. I know this is common in Europe.. just pointing out our standards would be very different.

[John Straube @jfstraube]

#buildingscience #ashrae and so it begins! The 15th Buildings conference in Clearwater Florida. Excited as always to hear from colleagues around the world doing buildings research. Betsy Petit from Building Science Corporation is giving the opening keynote address.

[John Straube @jfstraube]

@MarkSiddallRIBA @MontePaulsen @marine_gaelle @EnergyVanguard 1/RSI = U. (+/-3%). imperial R/5.678=RSI

[John Straube @jfstraube]

@MarkSiddallRIBA Perhaps the most important thing about the plot is the massive postive impact of exterior insulation: packing a stud cavity full of insulation or adding insulation to a wall is risky. Continuous exterior insulation reduces risk

[John Straube @jfstraube]

@MarkSiddallRIBA The same happens for cracks and holes: first all the water vapor than can condenses, then slowly proportion drops as air flow provides heat until finally, condensation stops and airflow dries the wall!

[John Straube @jfstraube]

@MarkSiddallRIBA Important point, especially when renovating existing (air leaky) buildings or comparing past performance to new ideas.... the full plot from Ojanen and Kumaran is based on quasi 1-D flow.

[John Straube @jfstraube]

#bscamp @RDHBuildings Graham Finch of RDH Building Science presenting at the Westford Symposium on Building Science. Deep dive into Mass timber and prefabricated enclosures.

[John Straube @jfstraube]

@MontePaulsen @bscamp @RDHBuildings Prof Bahnfleth of Covid ASHRAE task force have a great practical review with science references. See his prognostication for the future.

[John Straube @jfstraube]

The 24th annual Westford Symposium on Building Science aka Summer camp has begun. Great to be in-person with great experts @MontePaulsen @RDHBuildings

[Arnold Schwarzenegger @Schwarzenegger]

I love the Russian people. That is why I have to tell you the truth. Please watch and share.