I have 4 properties for which I am responsible for the gas and electricity
costs which are circa £5k per year. I have 11 flood lights, 4 gas boilers,
2 always on PCs, 4 routers, 4 washing machines, and a good selection of CFLs
scattered over the properties.
I would welcome any recommendations to reduce my energy bills!
What are the 11 floodlights for?
£1250 per annum per property doesn't seem too bad to be honest.
I'd recommend buying or borrowing one of those OWL energy monitoring
gadgets - they are quite revealing.
Seems incredibly good to me.
(I spend much more than that on one property.)
The OP should be awarded a green prize.
But they sound rather strange properties.
No TV? No microwaves or ovens? No immersion heaters?
Not if its a one bedroom flat :)
If the properties are rented and the tenants are not directly paying for
the energy what incentive have they got for switching off lights and
appliances when not required?
Flood lights are probably a waste. What are they lighting, and for how
On Sat, 21 Jun 2008 13:04:33 +0100 someone who may be "Mr Sandman"
What type, on for how long, doing what?
There is plenty of advice on the Interweb thingy. Do some basic
research first and then people may be more inclined to help you fine
The only thing I will say is that stopping energy loss is the first
thing to do.
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
On floodlights, if you have the usual 500W halogen lights, consider
going fitting lower wattage bulbs (you can get them down to 200W in
the same size bulb) or changing to high pressure sodium fittings.
You have to buy new fittings but they last a long time and the much
reduced power consumption compared to halogen floodlights means that
the payback period cannot be long.
I have also seen adverts for EcoFlood lights such as these, but don't
know anything about them:
They claim "High Lumen Output" but that could mean anything.
On washing machines, wash at the lowest temperature that gives
acceptable results. There are quite a few detergents that seem to
work well at 30C.
On Sat, 21 Jun 2008 13:04:33 +0100, Mr Sandman wrote:
Why? Flood lighting just to make the building(s) "look nice" at night is a
pure waste of energy. So called 500W "security" lights are anything but,
they just screw up you night vision and create black shadows that you
can't see into thus excellent hiding places.
Do both have to be on 24/7? I've just taken to switching my workstation
off overnight (moving a 24/7 monitoring task it was preforming to the
server). There has been a 2 unit/day drop in the power consumption, the
workstation is a 1GHz Athlon, the monitor was always turned off overnight.
Habit i suppose when ive need light outside, Ive just fitted floods,
generaly 500watt bulbs too, am considering replacing them with these..
http://www.tlc-direct.co.uk/Products/BGA5100.html I dont really need such
bright lights...the amount has increased
I need both PCs accessable remotly, i use logmein, and it wont work if the
remote PC is not on.
I have a couple of company's quoting to increase loft insulation, and one of
the properties needs wall cavity insulation, so will get that done.
Do they need to be continuously reachable or could they be run up on a
If you don't need much performance or the application is somewhat
embedded, there are lower power PC platforms around.
Of these, the most difference is likely to be from insulating the
walls. In most properties the heatloss through the walls exceeds
that through the roof and increasing insulation in the roof space if
there already is some, is second order compared with addding to walls
if there was none before.
oooo...this is interesting! I could set both desktops to hibernate after an
hour of inactivity, will Wakeonlan bring a PC out of hibernation, or only
sleep mode? Also, which MAC do I need, the network card on the mother board
or the MAC of the ADSL router? in the case of one of the PCs, it sits
behind a cable modem and a 4 way router...which MAC do I use in this case?
and which IP address do I use?
thanks for this!
On Sun, 22 Jun 2008 07:53:49 +0100, Mr Sandman wrote:
AIUI WOL will switch a PC on from off, provided there is mains connected
Got me there but I should imagine it is the MAC of the NIC of the PC you
want to wake up. A specially constructed broadcast packet is sent that the
NIC sees and turns it's host PC on.
By "4 way router" do you really mean a 4 way network switch or hub? A
"router" is a box that inspects packets passing through it and routes them
in the appropiate direction, which can include ignoring, dropping or
rejecting. A switch or hub is the box that connects all the network
devices together in a star topography.
The IP would have to be the public one of the cable modem, the MAC I
suspect is that of the PC you wish to wake up. Note you will need to set
up the cable modem to forward the relevant packets into your LAN and
configure the "4 way router" (if it really is a router not a switch) to
route them as well.
On Sun, 22 Jun 2008 10:02:51 +0100 (BST) someone who may be "Dave
I imagine it is what is called a cable router or broadband router
being one example.
Four internal network ports, switch, router and firewall built into
one box. It has one external network port which is plugged into a
separate cable modem (supplied by Virgin) or DSL modem (supplied by
oneself or the DSL company).
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
In the consumer networking sense, a "router" is a box providing NAT and
DHCP, and often also DNS caching, some sort of firewalling, and
sundry other small-network infrastructure services. A 4-port one also
incorporates a 4-port switch on the "internal" side of the NAT.
This is what the OP will have.
This is complicated. You need to get a packet onto the lan which the
PC will pick up. IIRC, the packet needs to contain the PC's ethernet
address concatenated 16 times. It doesn't matter what else is in the
packet, i.e. it doesn't matter what protocol(s) you use to carry the
What you probably can't do is simply send the packet to the PC, even
assuming your router allows you to. After an hour, the router's ARP
cache will have forgotten the PC's ethernet address, and any attempt
to reach it directly will cause the router to issue ARP requests for
the ethernet address of your PC's IP address, which it won't respond
to because it's asleep. (Having said that, there are now some NICs
which will respond to ARP requests when asleep, but they didn't exist
when I originally played with this, and they need special driver support.)
Another way is to send to your LAN's broadcast address. This would
result in the router sending a broadcast ethernet packet. All systems
would pick it up, but as it contains only 16 copies of the ethernet
address of one system, only that one system is woken. This is what I
did. You will very likely need to configure your router to be able to
send to your LAN's broadcast address though. Also, if you use some
service such as above, you would probably need to configure your
firewall to allow it through. (I just tried the one above, and it
piggy-backs the wakeup on a UDP packet to the port specified on your
network's broadcast address.) If logmein does what I suspect it
does, your dynamic IP address could make this more complicated.
[email address is not usable -- followup in the newsgroup]
firstname.lastname@example.org (Andrew Gabriel) wrote in
This is correct, and probably the way to do it. The only minor
(ahem!) complication is that the majority (?) of consumer class
routers disallow port forwarding to the network broadcast address
Typically this is 192.168.x.255 where x = 0 or 1 depending on the
brand of router. However, broadcast traffic to the LAN from an
external WAN address is regarded as a security risk, so this may be a
You may find that entering 255 in the fourth field of the target
address is rejected when attempting to configure port forwarding of
the UDP packet (usually on port 7 or 9). If it is the case that it's
just the config screen data validation which is rejecting this, there
is a way to get round this by using the TamperIE tool (Google for it
- similar tools for use with other browsers probably exist). However,
if the router firmware prohibits forwarding to the broadcast address,
then that's insurmountable.
A bit of experimentation will help. Configure your router, then try
the tool here:
If you run a copy of Wireshark/Ethereal on a different PC behind the
router you shpuld be able to spot the incoming broadcast traffic. If
this arrives OK, there shouldn't be a problem. If it doesn't arrive,
then the router is blocking it. Provided you have port forwarding
correctly configured, that means you may have to try a different
brand/model of router...
Hope this helps
To email me, change the <AT> in the address below
Jumping on the wagon...
From my own point of view Andrew, I have 4 x PC's in our shop which are
left on. (paranoia about losing e-mails)
I have a permanent VPN connected between routers from home<->shop using
DYNdns so I am able to directly access each machine using TightVNC via
internal LAN IP address even run 4 sessions to all computers at once
without a problem.
From what you have said then, because in effect packets are going via
VPN and router has MAC addresses locked to private IP address then WOL
should work without a hitch for my set-up?
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