Re: Another ZigBee convert

[nobody@xxxxxxxxxxxx (Dave Houston)]

I don't think it's really much of a practical problem. Even with the limited
range of most X-10 receivers there are not that many who complain.

I have brick exterior walls and plaster interior walls with wire lathe (your
wire mesh) in the ceilings and around windows, doors and archways. I make
fairly heavy use of RF as my mobility is severely restricted.

Lutron's RadioRA system also requires 25-30' spacing and I've never seen
complaints about its reliability (only about its high cost).

As long as people understand that ZigBee is low power and requires fairly
close spacing, I don't think there will be many problems. Many ZigBee
devices will be battery powered so the lack of an outlet may not be a
problem. Most houses here have ample outlets anyway.

It may be more of a problem in Europe where stone and cement structures are
more common. They tend to be unfriendly to RF.

I think you'll find the NFPA codes are quite restrictive and assure that
construction materials are thoroughly tested for safety.

Joerg <notthisjoergsch@xxxxxxxxxxxxxxxxxxxxx> wrote:

>Hello Dave,
>
>>>I wonder how well that stuff holds up in practice. Many houses have
>>>in-wall insulation using fibers on an aluminum foil backer and this can
>>>include some inside walls. When I walk into our garage with anything RF
>>>such as a cordless phone or LAN it often quits.
>>
>> That type of insulation is usually only in exterior walls. Interior walls,
>> when insulated, tend to use batts with either no backing kraft paper
>> backing. I heven't been on a new construction site in many, many years but I
>> suspect most exterior flashing which once was foil based is now Tyvek based.
>
>Right, they do it differently on many houses today. The latest I have
>seen is what looks like "Concrete-Styrofoam mix" blocks. I hope they
>have investigated the toxicity in a fire before releasing that stuff to
>market.
>
>However, lots of the existing houses, especially upscale ones with
>people in there who'd have the dough for home automation, have aluminum
>backed fiber. It seems they kept huge rolls at the site and simply used
>it everywhere insulation was needed. Garage walls are one area because
>the garage is vented and very cold in winter, hot in summer. I have even
>seen foil-backed fiber in ceilings.
>
>Then there is the stucco craze to create that mediterranean feel.
>Decorating interior walls typically requires a metal mesh be tacked down
>first so the mortar has something to grab onto, just like outside
>stucco. When we move an FM radio to the north side of a lava rock wall
>some stations fade away. It can be the same behind tile walls that were
>done in the classical mud bed technique. In our case it's actually all
>floor areas because they floated a 2" mud bed onto mesh throughout.
>
>> That said, I have seen more reports of RF problems from Canada than from the
>> US and have wondered whether their insulation practices might be a factor.
>
>They probably use more aluminum because it reflects heat. In Germany
>pretty much any insulation was aluminum backed. When I did an attic
>there it was the only thing they had. No Kraft paper, too flammable.
>
>> Crestron is very high-end so I doubt they would introduce something that
>> isn't reliable or that requires excessive service calls. Their customers,
>> dealers and installers would not be happy.
>
>Hopefully. Testing for RF blinding requires lots of miles through all
>kinds of different types of houses, analyzer in hand.
>
>> Most of the RF mesh networks require devices to be rather closely spaced
>> (20-25'). The devices act as repeaters so overall range is not a major
>> factor. It does mean that the number of devices tends to grow geometrically
>> with the volume needing coverage (which is a plus for the manufacturer). If
>> the protocol is a routed one, it also means that it may take several hops to
>> traverse the network which may mean delays and even missed signals if the
>> max hops is too low to traverse the network.
>
>This "mote approach" can work nicely. But it does get old if there is a
>spot where you have to place a mote just for repeater purposes and then
>there is no power in that area.
>
>Regards, Joerg
>
>http://www.analogconsultants.com