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Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
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    • CommentAuthorborpin
    • CommentTimeNov 8th 2014
     
    Posted By: Ed DaviesIf they can then they're inexcusably badly engineered. There was a time when car remotes could be intercepted (and they were - there was a black market in little boxes to listen to people locking their cars and to produce the appropriate code to unlock) but now they use cryptographic techniques to stop that.

    I have to admit I'm not clear how they work - they use a long cycle of codes and when one has been used it's blocked off for a while to prevent replay attacks. What I don't understand is how that works with multiple fobs and lack of, AFAIK, two-way communication.
    Recent item on BBC about some makes of cars being uninsurable as the keyless systems were being hacked.

    Basically, the manufacturers must be able to provide a dealer with the ability to break into a car if the keys are lost. That kit is then acquired by gangs and high end cars stolen to order and shipped out the same day.

    Reminds me of the old Thunderbirds episode when Parker broke into the BoE (took ages) then broke in with a hair clip. Nothing new. My mum said as humans we cannot imagine something we cannot actually do.
    • CommentAuthorEd Davies
    • CommentTimeNov 8th 2014
     
    OK, but getting hold of some manufacturers' kit is slightly different from intercepting the signal which was the point I was responding to.

    Still, it's pretty stupid if there's a box which can generate keys (mechanical or software) for arbitrary cars without leaving a record at the manufacturer's site and being able to be disabled if there's any indication that it's being used improperly.
  1.  
    "Basically, the manufacturers must be able to provide a dealer with the ability to break into a car if the keys are lost."

    Not quite. The rule is that manufacturers must allow independent locksmiths to create keys.

    The manufacturers decided to do this by allowing the car to programme it's own key, if presented with an authorised device.

    Their thinking was that they could track and control said authorised devices and how many keys were made with them. Unfortunately they're a bunch of muppets as far as computer security goes and using the (published) details of how the systems work some clever ladies and gents worked out how to authorise their own devices to make the car programme a key.

    Current production will be eminently nickable for years to come. Anybody fancy a cheap Range Rover? ;-)

    House security is rather easier as you can't flog your house in Albania or break it for spares. Physical security is only as good as your windows are; forget the locks...
    •  
      CommentAuthorSteamyTea
    • CommentTimeNov 8th 2014
     
    Does anyone remember the late 80's and early 90's craze of ram raiding. Seems an effective method of getting in. Though maybe not so good on a timber frame place.

    There was a cash machine in the town my Mother lives in that got removed with a stolen JCB. JCB have keys.

    Probably the best people can hope for is to get high quality images of thieves that can be used as evidence.
    And I still think that the siren of a burglar alarm needs to be indoors, and louder, that will learn them.
    • CommentAuthorEd Davies
    • CommentTimeNov 8th 2014
     
    Posted By: markocosicThe rule is that manufacturers must allow independent locksmiths to create keys.
    Do the locksmiths have to be able to do this without getting some sort of car-specific code from the manufacturer? If so, who makes this rule?
    • CommentAuthorbarney
    • CommentTimeNov 8th 2014
     
    There's nothing new - in my yuf, knowing where to hit a car crash sensor (hard) usually opened all the doors and triggered the air bags whilst knocking out the immobilizer - slash the bag with a stanley knife, short bit of scaffolding pipe on the ignition lock and away.

    Half a tennis ball over the lock or a bit of plastic strapping (depending on model) in the door edge were equally effective in"skilled" hands

    Joyriding was the entertainment of choice back then - and all you needed was a hoodie or a baseball cap to defeat the CCTV

    Effectively all you can really do is make your place (or car) more awkward than your neighbours to get at - if someone even vaguely wants what you have then they'll get it without too much trouble.

    Remember the spate of blow lamp entries via the foam core panel on so called secure uPVC doors - and all those windows with external beads

    Right, enough from me otherwise Mr Plod might be paying a visit

    Regards

    Barney
  2.  
    My line of work involves protecting financial details (as a side-effect of doing useful things for the account holders) and the idea of a parallel to the car situation, where we were forced to leave a gaping security hole open for independent "password smiths", is just laughable.

    Goes to show how protecting a trade can really give the shaft to everyone else.

    It should be trivial to make a solid security system for a car (although ultimately it's never going to be harder to steal something than it is to threaten the owner into giving it up).
    • CommentAuthorwholaa
    • CommentTimeAug 19th 2020
     
    Hi, I thought I should revive this old thread and share this German made insulated Euro cylinder lock. https://www.dormakaba.com/ae-en/solutions/products/mechanical-key-systems/cylinder-locks-with-reversible-keys/tic-thermally-insulated-cylinder-242140
    • CommentAuthorMike1
    • CommentTimeAug 20th 2020
     
    Posted By: wholaaI thought I should revive this old thread and share this German made insulated Euro cylinder lock.

    Good spot - useful to know!
    •  
      CommentAuthordjh
    • CommentTimeAug 20th 2020
     
    I've never heard of Dormakaba. Has anybody? I'm a bit concerned about the instructions not to overtighten screws and to use burglar-proof rosettes - I don't fully understand it, but I do remember that one technique with conventional eurocylinders is to break the cylinder in the centre, so I imagine that is a lot easier with a plastic section.
    • CommentAuthorrevor
    • CommentTimeAug 21st 2020
     
    I have never heard of them either. It is a timely posting as I am in the middle of fitting a 3 point lock to a door and have a Yale cylinder with it. Key does not glide in very well. I have had trouble with the lock itself as the euro holes in the plates of the lock do not align perfectly so when the cylinder is fitted it is not square to the plate so the end of the cylinder fouls on the hole in the door handle on one side. I requested a replacement and that was the same. Got China DNA all over it but with no indication where it was made I guess that this where it is from. Will have to ease the hole in one of the lock plates to get a neater fit.
    • CommentAuthorCliff Pope
    • CommentTimeAug 21st 2020
     
    The answer to the original problem is to not have a permanent pair of handles and a square section bar, but keep a loose handle with bar handy on each side.
    It could sit on a shelf or hang on a chain. If it hung on a chain you could push it out from the other side without needing to open the door again.
    •  
      CommentAuthordjh
    • CommentTimeAug 21st 2020 edited
     
    Posted By: Cliff PopeThe answer to the original problem is to not have a permanent pair of handles and a square section bar, but keep a loose handle with bar handy on each side.
    It could sit on a shelf or hang on a chain. If it hung on a chain you could push it out from the other side without needing to open the door again.

    Thanks for the novel idea :bigsmile:

    It would also need little plugs to block the hole when the handle wasn't in use, to maintain the airtightness.

    I think I might consider electronic locks before such a scheme, given SWMBO's likely reaction :devil:
    • CommentAuthorwholaa
    • CommentTimeAug 21st 2020 edited
     
    Posted By: Ed Davies
    Posted By: Cliff PopeSuppose the cross--section of the lock is equivalent to 30 mm by 30 mm steel and the door's 50 mm thick. Steel is said to have a conductivity of 43 W/(m·K) (http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html) so the conductance of the lock is:

    >>> 43 * .03 * .03 / .05
    0.7739999999999999

    = 0.774 W/K. Over a 4000 degree-day heating season that's:

    >>> 0.774 * 4000 * 24
    74304.0

    74 kWh.

    For a pretty small Passivhaus that's 1 of your 15 kWh/m² gone.



    Based on this assessement, what would be the rational amount to pay for such a lock?
    • CommentAuthorjms452
    • CommentTimeAug 22nd 2020 edited
     
    Posted By: wholaaSuppose the cross--section of the lock is equivalent to 30 mm by 30 mm steel and the door's 50 mm thick. Steel is said to have a conductivity of 43 W/(m·K) (http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html) so the conductance of the lock is:

    >>> 43 * .03 * .03 / .05
    0.7739999999999999

    = 0.774 W/K. Over a 4000 degree-day heating season that's:

    >>> 0.774 * 4000 * 24
    74304.0

    74 kWh.

    For a pretty small Passivhaus that's 1 of your 15 kWh/m² gone.


    Stainless steel is four fold less conductive than steel so that would be an easy win in the above equation.

    However, in this case the heat flow will be limited by the resistance of the air 'touching' the metal on both sides.

    If you think of it as akin to single glazing, factor in the increased area of the door handle (rather than just the cross section through the door) it's circa 1 kwH/year.

    The much bigger win, that also helps the door handle heat loss, is to have a porch big enough to act as like as airlock and use it when it's cold...
    •  
      CommentAuthordjh
    • CommentTimeAug 22nd 2020
     
    Posted By: wholaa
    Posted By: Ed Davies
    Posted By: Cliff PopeSuppose the cross--section of the lock is equivalent to 30 mm by 30 mm steel and the door's 50 mm thick. Steel is said to have a conductivity of 43 W/(m·K) (http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html) so the conductance of the lock is:

    >>> 43 * .03 * .03 / .05
    0.7739999999999999

    = 0.774 W/K. Over a 4000 degree-day heating season that's:

    >>> 0.774 * 4000 * 24
    74304.0

    74 kWh.

    For a pretty small Passivhaus that's 1 of your 15 kWh/m² gone.



    Based on this assessement, what would be the rational amount to pay for such a lock?

    Where did this 'quote' come from - it's not from this thread?
    •  
      CommentAuthordjh
    • CommentTimeAug 22nd 2020
     
    Posted By: jms452
    Posted By: wholaaSuppose the cross--section of the lock is equivalent to 30 mm by 30 mm steel

    The lock doesn't go all the way through the door. Only the square spindle does - they are 8 mm square nowadays.

    The much bigger win, that also helps the door handle heat loss, is to have a porch big enough to act as like as airlock and use it when it's cold...

    I built a large overhanging porch on our front door, to provide a dry area. I didn't enclose because it's north-facing and I read a lot of stories about the difficulty of keeping such spaces condensation free on a passivhaus.
    • CommentAuthorwholaa
    • CommentTimeAug 22nd 2020
     
    Posted By: djh
    Posted By: wholaa
    Posted By: Ed Davies
    Posted By: Cliff PopeSuppose the cross--section of the lock is equivalent to 30 mm by 30 mm steel and the door's 50 mm thick. Steel is said to have a conductivity of 43 W/(m·K) (http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html) so the conductance of the lock is:

    >>> 43 * .03 * .03 / .05
    0.7739999999999999

    = 0.774 W/K. Over a 4000 degree-day heating season that's:

    >>> 0.774 * 4000 * 24
    74304.0

    74 kWh.

    For a pretty small Passivhaus that's 1 of your 15 kWh/m² gone.



    Based on this assessement, what would be the rational amount to pay for such a lock?

    Where did this 'quote' come from - it's not from this thread?
    The first pager of this thread.I messed up the html
    • CommentAuthorjms452
    • CommentTimeAug 22nd 2020
     
    Posted By: djhI built a large overhanging porch on our front door, to provide a dry area. I didn't enclose because it's north-facing and I read a lot of stories about the difficulty of keeping such spaces condensation free on a passivhaus.


    We're some way off passive house but made the porch (Also north facing) within the thermal boundary of the house but unheated.
    It works well, limiting the cold air exchange when we go in/out and sitting a little bit cooler than the main house temperature (it's where we keep the veg).

    To avoid condensation we don'd leave wet coats etc in it to dry in the winter (mainly as it's not piped into the MVHR) and the only condensation we get is on the lock/hinges when it's really cold outside.
    • CommentAuthorJonti
    • CommentTimeAug 23rd 2020
     
    Build yourself a decent porch maybe?
    • CommentAuthorJeff B
    • CommentTimeAug 23rd 2020
     
    <blockquote><cite>Posted By: Jonti</cite>Build yourself a decent porch maybe?</blockquote>

    That's what we did. We replaced the existing porch with a pukka DG job and new exterior door (all uPVC, sorry). The "front door" (i.e. the door leading from the porch to the hallway) has also recently been fitted with a better draught-proof threshold seal as a belt and braces approach. All this has made a big difference to the hallway; the feeling of "coolth" around the entrance has gone and draughts eliminated. We still have a heavy curtain which we used to draw over the door in the winter evenings but the acid test will be if we still need to use it this winter.

    I guess the door handles are still thermal bridges but sometimes I think we are in danger of going completely OTT on this subject like being concerned about the thermal conductivity of a few screws in our carefully installed IWI! Sorry for being a heretic.
    • CommentAuthorJonti
    • CommentTimeAug 23rd 2020
     
    Posted By: Jeff B
    Posted By: JontiBuild yourself a decent porch maybe?


    That's what we did. We replaced the existing porch with a pukka DG job and new exterior door (all uPVC, sorry). The "front door" (i.e. the door leading from the porch to the hallway) has also recently been fitted with a better draught-proof threshold seal as a belt and braces approach. All this has made a big difference to the hallway; the feeling of "coolth" around the entrance has gone and draughts eliminated. We still have a heavy curtain which we used to draw over the door in the winter evenings but the acid test will be if we still need to use it this winter.

    I guess the door handles are still thermal bridges but sometimes I think we are in danger of going completely OTT on this subject like being concerned about the thermal conductivity of a few screws in our carefully installed IWI! Sorry for being a heretic.


    :bigsmile:
    • CommentAuthorwholaa
    • CommentTimeAug 23rd 2020
     
    Posted By: Jeff B
    Posted By: JontiBuild yourself a decent porch maybe?


    That's what we did. We replaced the existing porch with a pukka DG job and new exterior door (all uPVC, sorry). The "front door" (i.e. the door leading from the porch to the hallway) has also recently been fitted with a better draught-proof threshold seal as a belt and braces approach. All this has made a big difference to the hallway; the feeling of "coolth" around the entrance has gone and draughts eliminated. We still have a heavy curtain which we used to draw over the door in the winter evenings but the acid test will be if we still need to use it this winter.

    I guess the door handles are still thermal bridges but sometimes I think we are in danger of going completely OTT on this subject like being concerned about the thermal conductivity of a few screws in our carefully installed IWI! Sorry for being a heretic.


    I think it is all about cost / benenfit. Windows are going to be far more difficult weak spots thanlocks but they always cost a fortune to change. A door handle and lock is small but it it might also be cheap to improve.
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