Are we about to get a repeat of the 2021 power crisis in Texas... 1

[CWB1]

The bigger issue is the lack of residential energy efficiency, its the 21st century yet southerners are still living in poorly insulated shacks.

 

[SnTMan]

To retrofit / super-insulate an old house is difficult and expensive. Landlords don't want to spend the money when tenants pay the utilities. Owners don't want to spend the money when their duration of occupancy is not known...

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TugboatEng]

The bigger issue is the lack of residential energy efficiency, its the 21st century yet southerners are still living in poorly insulated shacks.

I resemble this remark, mostly! Because I live in an energy efficient state (California) I will likely never be able to afford to improve said situation.

 

[1503-44]

You may not be able to afford not doing it.
Will greater climate extremes increase your power usage more than the future cost of energy?
Insulation is the most cost efficient method to conservative energy. If you can't afford it, hope for no additional energy cost increases, or sell and buy a smaller house are about your only remaining options.


--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[Alistair_Heaton]

This is what UK is struggling with the switch to heatpumps.

If you do go down the insulation route be really really careful with ventilation especially blocking the eves of roofs. People are getting waterfalls of condensation in the UK after upgrading roof insulation done by clueless cowboys.

 

[waross]

Can you give an explanation of how the upgrade is causing the condensation?
Thanks Alistair.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[LionelHutz]

Don't you know the necessity of venting the attic space above an insulated ceiling or what happens if you don't?

 

[1503-44]

Ideally all surfaces within the house envelop should be higher than condensation temperatures.
Adding insulation at ceiling level stops the attic from warming via heated areas below. The attic will often cool to condensation temps. Then you have a rain making machine up there.
If you also insulate the underside of the roof, you will retain enough heat in the attic to prevent it falling to condensation temperatures.
Dont forget the vapor barriers.

https://www.reimerroofing.com/blog/attic-condensation-in-winter-what-causes-it-how-to-prevent-it/

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

 

[CWB1]

My condolences Tug, but you know the definition of insanity - living in the PRC and understanding the cost of liberal politics.

The affordability of upgrading older homes is irrelevant bc stateside its the market, not residential code that drives owners to upgrade. New construction is obviously required to follow the latest insulation standards but nobody cares if a few folks choose to live in a cold/hot/inefficient/expensive/etc home. In northern states most folks prefer not to be uncomfortable or have high energy costs, so the market places a much lower value on homes that aren't upgraded to recent local code norms, driving owners to upgrade. Personally, I've done very well amidst job-hops by buying older undervalued old homes, upgrading, and selling during my next move.

Unfortunately, if local code is crap then new homes are crap and older homes will tend only to be upgraded to crap. I love our southern states but their insulation standards are generally crap....and folks die from the cold. Meanwhile, my MI home has enough insulation that solar and earth gain alone keep it ~50F when we have one of our regular 3-5 day winter power outages.

 

[Alistair_Heaton]

 

[FacEngrPE]

Building envelope detailing can create condensation problems and sick building trouble in any size building.

Just having a vapor barrier is not enough. It's placement must be on the side of the wall that can drive moisture into the insulation. In the southern US the temperature and humidity ranges can appear to require a vapor barrier at the inside wall in the winter (Indoor dewpoint above outside temperature), and the outside wall in the summer (summer dew point above inside space temperature). Mitigation of this paradox can be fun.

https://technicalassurance.com/knowledge-center/building-envelope-water-moisture-management/

 

[Alistair_Heaton]

Its really causing issues in the UK with the upgrades linked to heatpump installs and government grants for it.

A lot of the installations don't seem to have any knowledgeable design input or quality check afterwards.

There also seems to be loads of confusion over mixing technology so you get sealed warm roofs with gaps between the vapour permeable membrane and the insulation so the vapour condensates on the membrane without getting through it and then runs down the bottom or soaks into the surrounding wood.

Then there are others that block the eves ventilation as detailed in that picture.

Then there is a growing issue with the sprayed foam between the rafters which was all the craze 10 years ago as the roof timbers are now all rotting.

And ventilation seems to be used as a cure instead of a primary part of the design.

 

[waross]

Thanks for the explanations, everyone.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[Alistair_Heaton]

its quite interesting to be honest Waross I went through the research for the barn roof.

Mine has to deal with -30 degs in the winter outside and internally up to 20 degs. RH90% outside inside goes down to 5% when heated.
Summer up to 35 deg's and again internally 20 degs, RH outside 40-60% internally cooled 80%

My solution was permeable membrane on outside with no gap, 300mm insulation gap then wooden panels. ventilated top and bottom. Outside 45mm trapezoid sheet metal.

Then two of these.

https://blaubergventilatoren.de/en/series/vento-expert-a100-1-s10-w-v2

At the top of the gables on the principle warm humid air rises. And they have a summer mode which just blows one direction.

 

[FacEngrPE]

Alistair your solution is clever. The vapor barrier is inside the material stack, which is likely appropriate for both summer and winter design. The best location is where the temperature at the vapor barrier is always above the dew point at the vapor barrier surface, resulting in no condensation.

 

[JStephen]

Well, we made it through the first cold spell with no loss of power here at the house. Had two outside faucets freeze up, but they thawed without damage. Got another front blowing through in the morning, but not supposed to be as cold as a couple of days ago. So all is good.

 

[Alistair_Heaton]

per say with these modern membranes there is no vapour barrier. From what I can tell you have to try and not have open faces in stagnant air that are cold for the condensation to form. Once the fluid is formed then its trapped if its inside your building envelope.

Vapour will be driven from hot to cold and also density differences will make it rise.

Then there is preventing the vapour/fluid going into the insulation. Which the local solution is barrier membrane just behind the final wall layer. But then your living inside a plastic bag...

 

[cranky108]

You do know they make outside faucets that should not freeze.

 

[Alistair_Heaton]

this is what I use in the garden. It was used last week in -20 C.

https://www.oras.com/en/design-lines/oras/garden-valve/431520

The actual valve is internal to the building, and when you turn it off it drains the section between the valve and the outside connection.

 

[LionelHutz]

They work as long as the inside part is exposed to the interior air of the building. They can still freeze if insulation is stuffed around it or it is enclosed into a wall or joist cavity.