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Keeping Computers (And People) Warm In Winter?
Grimwiz writes "Similar to a few of you, I have some of my computers on a UPS. However, the UK press have recently been warning that power supply interruptions are likely this winter and I've been pondering about upgrading my power protection from those few machines to include a few key house components. In particular, I need to ensure that the gas-powered (but electrically controlled) central heating stays working. I have reviewed a few solutions, including Solar / Photovoltaic or purchasing a generator
but they seem to be hugely more expensive than my simple UPS solution, although they do provide a much longer lasting solution than running off batteries. (A battery solution becomes quite expensive if I require more than an hours backup.)
My power requirements for a quiescent house is about 4amps @ 250V, and I'd like to survive at least 8 hours. What solutions do you recommend?"
Use a normal UPS to bridge the first few minutes in which you can comfortable start a generator.
so sticking batteries in series to 250v is not going to be a good move.
stick em in parrallel and hook up a 240V inverter.
32ah is a bit on the weedy side, around 110ah is standard and easy to find. over in the uk they tend to be called leisure batteries. dont use normal car batteries they are not designed to be run down - you will damage them
If you have gas then you can get a natural gas electrical generator. Connected to the gas line, when power goes out some models will automatically ignite and provide power to the house, some require a manual ignition.
Another approach you could take is to take steps to make your household more energy efficient -- upgrade your insulation, get energy star rated appliances, change to flourescents -- all of those things we should have learned in school and keep learning about in the adverts that come with our energy bills.
You could look into alternative energy sources, but since cost is a factor, I won't go into details, except to say the up-front costs can be prohibitive.
In all honesty, a generator IS your best option if you want to keep running in a blackout. You may be able to poke around and find a used one for 1/3 the cost of the new article.
If that's still not an option, build a fire pit and stock up on wood...
Who modded this informative? 250 volts DC is not the same thing as UK line power. (250 Volts-rms @ 50Hz.) This idea is as dangerous as it is useless.
What you need is an inverter. The cheap ones that you can get anywhere would work fine for your computers, but for your furnace you'd need an inverter of the caliber used in off-grid homes. (Probably more than you want to spend.)
Only in a Slashdot fantasy can a Slackware install turn into several hours of sex . . . . .
your tips are right except for the joke about the liquor. getting drunk will increase your chances of death in extreme temperature.
It does suprise me the number of people in civilized lands that are completely clueless to human survival.
If the house get's to 1 deg C your pipes are still very safe 0.5degC is where I would start to worry. about the pipes. Being used to winters regularly getting to -5 to -10degC and recieving at least 36-48 inches of snow by mid winter I usually get a good laugh from those that live in warmer climates and their lack of knowlege about life.
I would add to your tips. dress in lots of layers. a couple of undershirts with a regular shirt, a sweater and then a baggy sweatshirt, 2 pairs of pants on and then a regular jacket coupled with gloves and decent boots (3 pairs of socks, 1 plastic bag over each foot (if you venture outside) then in medicore boots can survive quite a long time in -3deg C weather out of the wind and elements. a Hat is a MUST if you venture out in any wind.
your computer can get down to -30 degC before possible dsamage, and then it's highly unlikely. This is negated by the silly people with water cooling and not using ethelyne glycol for freeze, heat protection.
layers are important, buy some long underwear or sweatpants just in case. In fact a pair of regular underwear, long underwear, and two pairs of jeans will easily protect a walking person in arctic temperatures if DRY for days.
finally, gloves. get some that are decent and good socks/boots. you can survive horrible temperatures while your nose., fingers and toes freeze solid and then fall off days later.
finally if it getr's really horrid, pitch a tent in your front room (a 4 season tent) and sleep in there. containing your heat in a smaller space will protect you massively in extreme temperatures.
but the best thing is to find a female that is unprepared and scared and convince her that she and her 2 friends must sleep naked together in that tent with you in order to survive...
you know use that shared body heat angle.. Chicks love the prepared rescue type... oh and don't shave for a day or so to look rugged... they dig that too...
Do not look at laser with remaining good eye.
Better yet, one of the hybrid gas/electrics, those things basically have what amounts to a mega-super-duper alternator, and you can plug right into the vehicles.
I just got back from Epcot, where GM had a display about their gas/electric hybrid pickups and how they were used during the Florida hurricane's as mobile power generation stations. Apparently you can plug right into one of them, and they'll give you 120 VAC @20 amps, which is not too shabby. (No doubt the UK model serves up 240VAC)
I don't need no instructions to know how to rock!!!!
You see, most UPS systems are rated in "volt amps". If you have a purely resistive load, that's the power drawn. However, as soon as you throw any inductors or capacitors into the circuit, the equation no longer holds. This is where the power factor comes into the equation.
You're talking about 4 amps at 250 V, over a period of 8 hours. That's 1000 watts for eight hours, or 8 kilowatt hours. However, this doesn't cater for the power factor -- if your house has a power factor of 0.8, for example, batteries capable of providing that current for that period of time will run your house for about six and a half hours. So you'll need to bring up the batteries to 10 kilowatt hours to compensate -- either that, or (if it's an inductive load) buy a whopping great big bank of capacitors to bring the power factor back up to a reasonable level.
Industrial sites have to deal with this; the power company doesn't like sites that draw excessive current compared with their power usage, and will bill them big time if their power factor is too low. Most residential sites aren't a concern in this regard; their usage is too low for the power company to worry.
If you've specced it out based upon the current draw (ie: sticking a current meter in series with the circuit), you've automatically compensated for the power factor. If you've done the maths based upon the power rating of the devices, though, you need to consider this stuff. Any competent electrician should be able to help you out here.
See also this detailed article on what kinds of batteries might do the job. good practicle info.
"It is a greater offense to steal men's labor, than their clothes"
Agreed about AC and DC, but here is one thing to keep in mind.
If you run an incandesent bulb off DC it will work just fine, and probably last a VERY long time compared to how long it "should" last.
I thought the UK ran at 240 volts, not 250. I thought South Africa was the only country that ran 250. I though most of Europe was 220 and Europe and the UK were going to unify their standards at 230. Anyone care to comment? BTW, Japan runs at 100 (the lowest, 250 is the highest) and I think Trinidad runs 110 (the USA does NOT, see below).
Of course the USA used to be 110 volts, but is now 120 volts, but so many Americans still don't know that. It actually causes problems with old tube radios.
Just because it CAN be done, doesn't mean it should!
You live in the UK, which tends to not have enough sun to make photovoltaic worthwhile. Either you need a positively huge array (and the one in the picture on the website you link to looks like it fairly covers all available space on the roof) or you need lots of sun and Britain just doesn't have that.
Your best (but polluting) source of electricity is a honda generator. You can buy them all over and I'd imagine a DIY outlet will have a few models to choose from. One member here mentions that he did quite well after a hurricane with one. Do not ever run one indoors. They create carbon monoxide so their exhaust needs to be away from the house so that it cannot seep in through a window, vent or other entrance.
You will need a UPS with a generator if you are running a computer, but you don't need one for equipment that may be shut off and restarted, like fans, washers, dryers, refrigerators, etc. You need enough battery life to be able to survive a power outage until you can get the generator running. So if your computer needs to run all of the time, make sure your battery will last long enough for you to wake up, put on clothes and go tend to the generator.
Insulation and sealing are the best non-polluting way to increase heat -- and you will save money on heating fuel all winter, so it pays for itself.
The more insulation you have in your walls and on the roof, the better you are. Be sure there is an air pocket that runs up your eaves on your roof so that you don't get mold on your rafters and shingles and you're all set. You want to add to your "R-Value" in such a way so that you can keep enough home heat inside to keep warm in any full-day power outage.
The homes I've visited in England have tended to be fairly drafty as compared to US homes. So look at your doors and windows and make sure they seal well when you close them. Windows ought to be double-pane windows, which hold in heat four times better than single-pane.
I don't necessarily recommend that you keep up the electricity lifestyle during a power outage. Turn off your computer, unless you need it for work. Use hurricane lanterns and "Coleman" white gas lanters with mantles to light up your home (they'll also add heat but not as efficiently, perhaps, as a real heater). Run up your heater on your generator until it is quite warm inside and then shut it off until things cool down just under bearable temperatures. Don't open any windows to moderate the heat and keep things sealed up as best you can. Don't use the television, save to get information about the power emergency (a radio is usually better anyway for up-to-the-moment information anyway). Run your generator sparingly.
And talk to your local MP and ask why your area is so ill-served with electricity. Ask if his district is not one of second-class citizenry if your power goes out as often as is predicted. Gather your friends and neighbors to help him think more clearly (if he sees you as a voting bloc, he'll think clearly) about the need to introduce a change in the system.
Gods don't kill people, people with gods kill people.
You can run a gas furnace off of the heat generated from the pilot light using a thermopile and a millivolt controller gas valve. I have heated my house this way in the middle of winter over a 3 day ice storm blackout.
It must be a hot water system. Just open all of the zone valves and eventually the whole system will heat up to the furnace temperature via convection in the pipes. The furnace will cycle between its low and high temperature, even with no power except the thermopile.
This is a standard type of system in the US. Not sure about the UK.
See http://hearth.com/what/gas/howgasworks.html for info on millivolt gas systems.
A co-worker had seen the exact same thing happen in his last job.
I'm not familiar with what "VRLA" means, but unless the battery is sealed gel-type and rated for deep discharge and repeated cycling, I'd wouldn't use it.
Get your facts right. I don't know what coverage you're reading (the tabloid papers I suspect) but there is no power supply crisis forcast for this winter.
What has been commented on is our increasing reliance on imported power from the continent, and coupled with the decommissiong of several major nuclear power plants over the next decade if we don't act now there could be problems in the future. I don't think UPS'ing your heating system is necessary just yet :)
"But the government said the outlook for power supplies this winter was good and accused the union of "scaremongering""
Source: http://news.bbc.co.uk/1/hi/business/3751810.stm
For all the posters in this thread :
DO NOT USE HIGH VOLTAGE DC IN YOUR HOUSE.
Apart from the obvious issue with appliances, there's another reason.
Mains 240V AC switches are not rated for that kind of DC voltage - the arc from switching DC at those voltages will most likely destroy the switch. This arc is only brief with AC at 50/60 Hz as the arc will extinguish when the voltage drops to zero every half-cycle.
This is why switches are normally rated along the lines of "240VAC/32VDC"
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
VRLA is Valve Regulated Lead Acid...VRLA is better than a sealed lead acid precisely because it will NOT explode- it will vent if charged too fast.
VRLA is a teensy bit different from a standard gel cell in terms of charge profile, but they're close enough that it shouldn't matter much; I think the float voltage is typically lower. HOWEVER, you DO need to make sure you match specifications ( and not just "12v", get the specs sheet and look at the charge, float, etc voltages), and be aware that VRLAs are not particularly fond of heat; adding a tiny fan to the UPS enclosure would probably be a swell idea anyway as the buggers tend to run hot.
The REALLY thorough will check the charge current from the UPS. UPS makers are under pressure to get the battery charged back up quickly, and they may push the limits of the battery's charge current. It's generally C/20 where C = A/Hr capacity; ie a 20Ahr battery should not be charged faster than 1A continuous (a brief peak charge might be OK, and if so, will be specified in current and duration). Charging too fast will cause gassing, overheating- and past a certain point, like many other batteries, lead acid batteries of any type can go into thermal runaway, which is not pretty.
Adding in extra batteries into a UPS not designed for expansion will be trouble, on the charging side of the equation. If you've ever had a completely dead car battery and tried to charge it with a charger, you know what I'm talking about- the voltage drop is so great, the battery practically acts like a short and will cause the charger to overload. The same thing could happen with a UPS. A good sign is if there are battery expansion packs available for your UPS; use that as a guide for sizing.
Oh, and by the way, you may want to consider adjusting your UPS to use the proper float voltage (not for the faint of heart, but possible on some UPS's without soldering), and again, installing a low-speed fan to move some air through the thing and keep everything cool. Many UPS vendors coughAPCcough set their float voltages too high and thus cook the batteries, and the elevated temperatures don't help either; that all makes for a nice revenue stream, as they charge a fortune for replacement packs(which are almost always made up of standard-size batteries, and thus available much more cheaply if you're the enterprising type). Properly maintained lead-acid batteries should last almost a decade- yet most UPS batteries die within a matter of 2-3 years. It's pathetic, considering how much lead is in them and how most people probably don't dispose of the UPS's or the batteries properly.
Please help metamoderate.
Actually, typical residential service in the US is 240V split-phase; the distribution transformer is center-tapped, and the center tap is grounded to serve as the neutral. Phase-to-neutral is 120, phase-to-phase is 240. Heavy-draw appliances, such as large air conditioners, electric ovens, dryers, etc. are usually run on 240.
Another system uses two of three phases on a 208V three-phase supply; phase-to-neutral is still 120. This is normally only found in apartments and commercial buildings.
Oh, no! You have walked into the slavering fangs of a lurking grue!
You're talking about 4 amps at 250 V, over a period of 8 hours. That's 1000 watts for eight hours, or 8 kilowatt hours. However, this doesn't cater for the power factor -- if your house has a power factor of 0.8, for example, batteries capable of providing that current for that period of time will run your house for about six and a half hours. So you'll need to bring up the batteries to 10 kilowatt hours to compensate -- either that, or (if it's an inductive load) buy a whopping great big bank of capacitors to bring the power factor back up to a reasonable level.
Umm you got it backwards.. Lets go to the facts..
Starting with some glossary terms..
Volts = Electrical pressure
Amps = Electrical current
Watts = Power
VoltAmps = Volts * Amps
Vars = Volts Amps Reactive.
Power Factor = Percent of Volt Amps that are Power scaled 0-1.
What's it mean?
If you drop a Capacitor on an AC line, it will draw current but not get hot unless it's not designed for the voltage, current, or polarity.
The current is said to be reactive. All of the current measured in VA is not Watts. The power Factor is zero. Volts * amps * power factor = watts. Most inverters don't like a highly reactive load. This may dammage it.
A light bulb gets hot. It is not an inductor or capacitor.. It has a power factor of 1. Volts * amps * power factor = Watts.
A furnace motor may have a power factor of 0.8. If it drew 4 amps at 250 volts it's VA = 4*250 or 1000VA. The actual power draw in watts is 80% of tthe VA. Remember power = Volts * Amps * Power Factor or 250 * 4 * 0.8 = 800 Watts.
So in the above example in the parant, the load draws 800 watts. If it draws it for 8 hours, that's 6.4 KWH not 10 KWH.
Remember that inverters don't like reactive loads. The inverter may take the reactive power and dump it as heat depending on the design. That's 200 watts of reactive power. You also need to scale for conversion consumption. The inverter uses power. It is not a lossless process.
If you run large reactive loads, save your inverter by looking into doing some power factor correction.
With a reactive load such as a transformer or motor, the current lags the voltage. In a capacitive load such as a noise filter, current leads the voltage. It is possible to correct reactive load problems with lamp ballasts, motors and transformers by adding capacitors to the line. You want a capacitor that has the same VAR rating as the load you are trying to correct. In the above example, we have a reactive component of 200 watts. (800 true watts subtracted from the 1000 VA leaves the reactive component of 200 watts reactive) Adding 200 watts capacitive reactance will cancel out the inductive reactance load. This will reduce the load on the inverter. Now it sees a 800 VA load, not a 1000 VA load. Now the inverter sees a power factor corrected to 1. The motor still draws 1000 VA but now gets the 200 VA reactive component from the capacitor, not the inverter.
I hope I didn't loose too many in the dry discussion of what a VAR is.
Anyway, this is the reason on some power poles, you may see a bank of capacitors. It is used to correct power factor and reduce the amprage load on a substation.
The truth shall set you free!