Grand designs yesterday evening, Topic 2

[JohnMo]

21 minutes ago, ProDave said:

If it really was divide by 20 them my 1.4 m3/m2 would be 0.07ACH.  No way is that the case.

If you have a look in your SAP report, for the infiltration valve for the heat loss calculations that us how they do.

 

Think the 50Pa is equivalent of a near hurricane on all sides of the building at the same time. Which isn't that realistic, for a heat loss calculation.

[S2D2]

25 minutes ago, ProDave said:

I thought the conversion from  m3/m2  to ACH was very approximately 1:1 but there is no simple universal conversion because it depends on the geometry of the house, i.e is it single storey, 2 storey, vaulted ceilings etc.

 

If it really was divide by 20 them my 1.4 m3/m2 would be 0.07ACH.  No way is that the case.

 

It's a rough way to get to the ACH value to use for heat loss calcs. Likely not linear so only applicable for "kind of leaky" houses. That said, modern houses that reach low values will be dominated by mechanical ventilation, so it's a moot point anyway.

[MikeSharp01]

On 10/11/2023 at 09:56, SteamyTea said:

passed my driving test, crashed sister's car 2 nights later, then my motorbike, twice, then my father's brand new car, got banned twice for my troubles

You managed  all that in 2.5 years since you were 17.5 when you passed your driving test. Presumably  the bans were not 1 year each!

[SteamyTea]

1 hour ago, MikeSharp01 said:

bans were not 1 year each!

15 months and a 6 months.

Second ban was for speeding, but had unspent endorsements.

 

[Post and beam]

On 10/11/2023 at 15:56, saveasteading said:

Each January, I pack away the decorations, tape the tops shut and store in the attic. Each December I find all tapes are unstuck. It must be the February chill or the summer heat.

I regard tapes as temporary fixings.

I doubt that Tescon Vanna Tapes and the like are of the same order of crappy ness( technical term) as your average sellotape. They are rated at 100 years of adhesion. (No i dont know how they test that either but i do trust them)

[Post and beam]

On 10/11/2023 at 15:56, saveasteading said:

Each January, I pack away the decorations, tape the tops shut and store in the attic. Each December I find all tapes are unstuck. It must be the February chill or the summer heat.

I regard tapes as temporary fixings.

I doubt that Tescon Vanna Tapes and the like are of the same order of crappy ness( technical term) as your average sellotape. They are rated at 100 years of adhesion. (No i dont know how they test that either but i do trust them)

[Post and beam]

On 10/11/2023 at 15:56, saveasteading said:

Each January, I pack away the decorations, tape the tops shut and store in the attic. Each December I find all tapes are unstuck. It must be the February chill or the summer heat.

I regard tapes as temporary fixings.

I doubt that Tescon Vanna Tapes and the like are of the same order of crappy ness( technical term) as your average sellotape. They are rated at 100 years of adhesion. (No i dont know how they test that either but i do trust them)

Apologies. Keyboard issue my end

Edited November 12, 2023 by Post and beam

[SteamyTea]

1 minute ago, Post and beam said:

No i dont know how they test that either but i do trust them

Rapid aging.

Cycle the tapes though the expected temperature and humidity ranges several times a day, when you get to 50% adhesion, you then extrapolate that to 100 years.

Alternatively you set a lower bound to the adhesion limit and rapid cycle until you reach it.

 

Rapid aging, time to failure and time between failures is an interesting engineering field, uses the Poisson Distribution to predict the end points.