#231480 - 09/06/11 02:08 AM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: MartinFocazio]
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Geezer
Registered: 01/21/04
Posts: 5163
Loc: W. WA
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If you have $300 worth of food in the fridge, and you need to run a generator for 7 days 24/7 to keep it on, it's often cheaper to just call the food a loss and run the generator intermittently. I was under the impression that a freezer only had to be on about four hours a day to keep the contents frozen. Is this wrong? Or were you just using it as an example? Sue
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#231495 - 09/06/11 06:57 AM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: Susan]
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Old Hand
Registered: 06/03/09
Posts: 982
Loc: Norway
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I was under the impression that a freezer only had to be on about four hours a day to keep the contents frozen.
Use a remote termometer (with cable) to monitor the freezer's temperature. I can't telly exactly at what temperature things start to spoil, but you should know that the water in the food will start to thaw well before the temperature reaches 0c/32f. It's not an immediate concern, but if the food is allowed to reach 0c/32f it really should be eaten as fast as you can, not stored for months and months after the ordeal is over. Ideally, it should be thawed and eaten right away. In a less perfect world you accept a degradation of quality and refreeze what you can't eat. Friend of mine had a tiny deep freezer in the bedroom his bachelor condo (-30c/-22f). That freezer disturbed him in his sleep. If he switched it off for 8 hours the temperature inside would be somewhere warmer than -10c/5f. It is not good for precious high quality meat to have that kind of temperature cycle every night. He used his knowledge of chemistry to mix denaturated alcohol and water to a freezing point of -20c/-4f. About half a gallon was plenty to make sure the freezer never got colder than that during his sleep. Add a timer to switch the freezer off between 11pm and 9am and you also have a bachelor's backup wake-up alarm...
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#231496 - 09/06/11 10:40 AM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: MartinFocazio]
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Old Hand
Registered: 08/18/07
Posts: 831
Loc: Anne Arundel County, Maryland
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My non-scientific observation is that folks 1. Panic 2. Buy a generator, any generator, 3. Start it up 4. plug things into it until they don't work.
The hardest thing for folks to understand is the need for "surge" power. When things with electric motors start, they demand more current then when running. Sump pumps and refrigerators/freezers are the most common, but some medical devices may also be in this category. You need a generator with the power to handle the "surge" demands as these motors start up.
When I was still using a portable gennie, I was able to keep the fridge and freezer cold enough by simply running one at a time for 4-5 hours, getting cooled down, then switching to the other. Usually (YMMV) a fridge or freezer can hold food at a safe temp for that length of time.
_________________________
"Better is the enemy of good enough."
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#231497 - 09/06/11 10:58 AM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: bws48]
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Addict
Registered: 05/23/08
Posts: 483
Loc: Somerset UK
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A freezer will stay frozen for from 4 hours to 36 hours without power, it really does vary that much. The shortest holding time would be for a small front opening unit that is not full, and in warm suroundings. The longest time would be a large, fully stocked, top opening freezer in a cold place. And remember that meat, for example is still safe to eat for at least a couple of days after it defrosts. Most freezers have a "fast freeze" setting, this reduces the temperature below that normally achieved. Use of this control before the power cut will reduce the internal temperature and therefore increase the holding time.
Refrigerators wont normally stay cold for as long. Perishables should be consumed promptly or discarded if the power is off for more than a few hours, unless of course an unheated area is at a similar temperature to the fridge.
A reasonable sized generator should be able to run a fridge and a freezer. As the fridge needs near continous power, it might be best to only plan on useing the fridge for perhaps the first 2 days of a long outage.
If preparing in depth for long term power outages it would be worth considering ultra high efficiency freezers and fridges. They use little power and can be battery powered, with the batteries charged by limited generator running, or from PV modules. My fridge uses less than 1KWH a week ! That would be a week from a single deep cycle battery, or months from a limited fuel supply used to run a generator for perhaps an hour a day.
Edited by adam2 (09/06/11 10:59 AM)
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#231500 - 09/06/11 12:51 PM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: adam2]
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Carpal Tunnel
Registered: 08/03/07
Posts: 3078
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My fridge uses less than 1KWH a week ! That is exceptionally efficient, even the very expensive Liebherr and Miele small larder refrigerators will be rated around 120Kwhrs/year. What type of fridge do you have? I know that you can operate a Vestfrost SE225 freezer to operate at a fridge with a thermostat controller which will get you around 36KWhrs/year. Enough to be easily powered in sunny weather by something like 60W PV panel/Pure Sine Wave Inverter and Deep cycle battery. http://www.builditsolar.com/Projects/Conservation/chest_fridge2.pdfAlso when powering AC motor equipment that use a capacitor start (most refrigerators and freezers) a pure sine wave output on the gennie inverter is a recommended such as the Honda Portable Silent Generator EU20i esp with a butane/propane gas conversion. (the fuel is much easier and safer to store on site than petrol)
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#231514 - 09/06/11 03:34 PM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: MartinFocazio]
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Pooh-Bah
Registered: 11/25/08
Posts: 1918
Loc: Washington, DC
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I'm just back from a friend's place in southern Maryland (on the Patuxent River near the Bay) where the power was off from Saturday (Irene) to Friday. I spent six days there. We think a small tornado or some other isolated wind event cut the straight-line swath of damage on the roads/utility poles leading out of the neighborhood.
TV cable back on two days later and it was just yesterday (Monday) that cable Internet functioned. The landline telephone still wasn't working when we returned to DC (Day 9 after Irene hit).
They'd had a backup generator (propane-powered) professionally installed a couple years ago after a blizzard. I just e-mailed them to ask precisely what make-model it is. It runs a lot quieter than the portable generators that ran at neighbors' homes (another reason to have earplugs around).
The propane was topped off the day before Irene hit. Six days later, the gauge showed 35% left. That ran the septic pump, well pump, sump pump, fridge-freezer full-time, ceiling fans, lights (too many, in hindsight), just-in-time hot water heater, washer-dryer, laptop computers, flat-screen TV for one movie each night. Fortunately, the house is on the water and heavily shaded (none of those trees fell, thankfully) so it was comfortable without a/c.
Did not use the stove/oven, microwave or other kitchen appliances other than the coffee maker. We cooked on the gas grill outside. Augmented lights with candle lanterns and other candles (carefully).
At the 35% point of propane storage -- and the roads still impassable to a propane delivery truck -- we began to be more conservative. Filled a huge Coleman x-treme cooler with 40 lbs of ice ($5 at BJ's) and sodas and bottled water to avoid opening the fridge and allowing shutting off the generator more frequently and longer. By the way, this Coleman cooler is one that I happened to have in the back of my Element. I often keep a cooler in there and threw this big one in for this trip - just in case.
We spent an hour at Starbucks in the mornings and evenings to use the Wi-Fi.
My friends now own their own 150-quart Coleman x-treme marine cooler.
Love the backup generator but it is expensive to operate and if the roads are impassable for fuel refill to run it then at some point you'll need to backup the backup if you're not real stingy in its usage.
The biggest bummer of the power outage for us was that the boat lifts didn't work so we couldn't lower the boats back into the water.
So we enjoyed low-tech, unpowered days at the beach. Would have been a lot more unpleasant during July's month-long heat wave.
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#231515 - 09/06/11 03:37 PM
Re: Generators Aren't Going To Solve Your Problems if.
[Re: bws48]
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Pooh-Bah
Registered: 03/08/07
Posts: 2208
Loc: Beer&Cheese country
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My non-scientific observation is that folks 1. Panic 2. Buy a generator, any generator, 3. Start it up 4. plug things into it until they don't work.
Man, this is so true. One of my "acquaintances" posted on Facebook the day before Irene hit: "Hey, I'm going out today to buy a generator. Anyone know a good brand?" Idiot... like there were any left in stock? (this was Virginia Beach) I wrote back: "Sure! First, what do you plan on running? Second, add up all the running currents from what you want, then take into account the surge power, so add 10-20% on top of that. Then get a lot of fuel and some oil. You're going to have to top both off at least once a day. Then get a chain or something to secure it, since they tend to walk away during disasters." She did NOT end up buying one.
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