|
| Author |
Message |
Dina95
Member
|
# Posted: 19 Jan 2013 08:16
Reply
Ok, so the fridge i am thinking is a Smeg FAB10H.
These are all the details about its performance i could find.
can anybody tell me what and how many solar panels and how many deep cycle batteries i will need?
I know nothing about electricity and yeah.... i hope someone can help! Thank you in advance! :D
PERFORMANCE
1 compressor
Energy consumption: 123 kWh/year
climatic class: SN-T
rising time: 10 h
noise level: 37 dB(A)
A+ Energy Class
Oh.. and here where i live in the worst weather conditions it was calculated to have at least 3.5 hours daylight(but lets say 2-2.5 hours just in case). hope this helps!
|
|
VTweekender
Member
|
# Posted: 19 Jan 2013 10:16 - Edited by: VTweekender
Reply
The energy consumption reads the fridge will use only between 300-400 watts a day....thats very low for a compressor....if true a 200 watt panel would get you by as minimum system, especially if not in use full time....two batteries at 200 AH plus or minus would also get you by......it would be close with a 200 watt panel system.....more on the safe side, and if you plan on a couple lights and TV you would go with 400 watts in panels...it would be important that the inverter in the system be able to handle the surge from a compressor, probably need 2000-3000 watt inverter..
|
|
Dina95
Member
|
# Posted: 19 Jan 2013 10:39
Reply
Thank you VTweekender!
Well... i don't know about the compressor but the capacity of the fridge is 135 liters! Only 200watt panel system? that will be "cheap" for the huge advantage of a fridge!
Yeah i am on the planing of my small cabin and i want to figure out the cost to save money! :p still need to clear the land for my cabin so it will take me time... School first! :p
What brand of batteries do you recomend?
Is trojan or crown a good brand?
|
|
Dillio187
Member
|
# Posted: 19 Jan 2013 10:43
Reply
I've found those labels grossly misleading. You really need to measure the devices actual usage using a device like a Kill-A-Watt over the course of at least a few days to get an accurate representation of what it will use.
|
|
Dina95
Member
|
# Posted: 19 Jan 2013 10:52
Reply
Isn't illegal to write wrong information on the label?
I know that the Smeg brand has one of the most efficient fridges!
Can you send me a link to the product you said?
|
|
sparky1
Member
|
# Posted: 19 Jan 2013 12:00
Reply
Smeg USA Inc.
A&D BUILDING 150 EAST 58th STREET 7th FLOOR
New York, NY, 10155
Tel. +1 212 265 5378 - Toll-free 866 736 7634
www.smegusa.com
Email: info@smegusa.com
Web: http://www.smegusa.com
|
|
Dillio187
Member
|
# Posted: 19 Jan 2013 14:15
Reply
http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU
|
|
Moving Pictures
Member
|
# Posted: 20 Jan 2013 22:36
Reply
I concur with the above advice: check the real-world power consumption....
|
|
|
Rossman
|
# Posted: 21 Jan 2013 18:59
Reply
Quoting: Dina95 Isn't illegal to write wrong information on the label?
Probably but the label can still be misleading. For example the device could have a high startup power draw, or a higher draw when the compressor is running, than the rest of the time (at idle).
In this case the rated wattage will not really tell you what you need to know.
Cheers
|
|
MtnDon
Member
|
# Posted: 21 Jan 2013 21:49
Reply
When "they" test fridges for power consumption they use a standard temperature. It's somewhere around 75 F, I am not exactly sure. If your location gets hotter regularly the unit uses more power and vice versa. Runnning your owm metered test in conditions similar to those where it will be installed would be great. But that is hard to do when you have not yet purchased it.
The power rated on the plate is meaningless without knowing how much it will run. That time length is related to the environmental temperature as mentioned above. The EPA publishes test figures for many makes and models. Google Energy Star. At least if the unit is listed you know all the others were tested under the same conditions so a comparison is likely fair and reasonable. How the numbers relate to your location is another matter. Unfortunately there is no place to get comparable test data on propane.
|
|
TomChum
Member
|
# Posted: 22 Jan 2013 11:35 - Edited by: TomChum
Reply
Quoting: MtnDon related to the environmental temperature as mentioned above
Some refrigerators optimized for home use don't work very well when outside temp is about the same as inside temp. Many are designed to be most efficient in a room temperature environment of 75 (?) degrees, but get all confused if they are outside on the porch at 35 degrees. They are not smart enough to simply "not run". Recreational cabin use can be a strange environment for a refrigerator optimized for "home use".
Also consider the thermal mass of the contents INSIDE the refrigerator. If the refer is empty it will run a lot, and be very inefficient. If you keep some thermal mass in it (if nothing else, use a gallon jug of water or two) it will operate as designed. And this will have an effect on the length of the test period necessary for comparison.
It seems to me that thermal mass in your fridge is similar to battery storage of "cold". Make cold while the sun shines (or while generator running), then suck off it all night. If you have empty space in your fridge, put more gallon jugs. I don't know this for a fact, but it makes sense. More sense than why a fridge would get confused running outside on the porch.
|
|
MtnDon
Member
|
# Posted: 22 Jan 2013 13:10
Reply
Quoting: TomChum , but get all confused if they are outside on the porch at 35 degrees.
The common residential refrigerator is made to operate in temperatures that would be consodered normal ny most peoples home heating standards. It IS possible to make refrigeration system compressor systems that will work at colder temperatures. Google garage fridge... there are some specially made ones. They will usually make the temp range readily available to find whereas the common kitchen fridge seldom mentions it.
Grocery stores and other commercial refrigeration uses systems that work well in cold weather. They have them on the roof in all kinds of weather. To make them work in the cold it requires some equipment changes; it costs more and since most home fridges don't need it they are not built that way.
|
|
Dina95
Member
|
# Posted: 22 Jan 2013 14:43
Reply
Thank you guys!
As VTweekender said it will use about 400 watts a day,
and suggested 200 watt panel with 2 batteries at 200 AH (what ah means? i don't know, anyway)
In the summer, watts won't be a problem... we get at least 8 hours of sunshine everysingle day! (my friend went to the beach for an hour everyday only for 2 weeks and she was like from white chocolate to nutella!)
In summer i care about the batteries! If the fridge (as you say) overworks in the summer to keep the tempeture the same, will i need more batteries?
And please explain what AH means!  
|
|
VTweekender
Member
|
# Posted: 22 Jan 2013 15:12
Reply
AH is "amp hours", a 200 amp hour battery is a good size......when you look at deep cycle batteries the capacity will be in amp hours. Two deep cycle 200 AH batteries should work just fine in the summer....thats if the fridge is really only using about 400 watts a day..
|
|
Dina95
Member
|
# Posted: 22 Jan 2013 23:36 - Edited by: Dina95
Reply
Oh i think i get it now.. so for every 1 watt is used i need 1 AH in the battery system, right?
Which means if i have a 600 Watt system i would need 600AH battery system too, am i right? :D
But if i don't want to drain the batteries, i should double that amount, right? Because if it was correct (i read that somewhere) it shouldn't go below 50% percent of its capacity!
Oh, i think now i know little more about Renewable Energy! I am soo proud! 
|
|
VTweekender
Member
|
# Posted: 23 Jan 2013 01:41
Reply
The watts and amps are not the same, your battery bank should have enough capacity to run for 3 days.........You are correct that you don't want to drain more than 50%......I was thinking that fridge would use about 70 amps a day, so a 400 AH bank would drain about 50% in 3 days with just the fridge running......you want to calculate 3 days storage in case of 3 real cloudy days in a row...
|
|
Dina95
Member
|
# Posted: 23 Jan 2013 08:55
Reply
We get cloudy days but is really rare to be all day long and for 3 days! But its better to be safe than sorry. so 2 battereis it is!
I found a site that helped me understand how to find apms and watts and things like that! :p
Its 80 amps if it uses 400 watts a day!
Also another question... the power in the batteries is DC 12 volt...
The inverter makes the DC 12 volt to turn to AC 120 volt?
Another question, in the battery specifications it says
82AH @ 5hr-rate
100AH @ 20hr-rate
111AH @ 100hr-rate
All about the same battery! and i really don't get it!
can anyone explain this to me?
|
|
MtnDon
Member
|
# Posted: 23 Jan 2013 10:13 - Edited by: MtnDon
Reply
Quoting: Dina95 82AH @ 5hr-rate 100AH @ 20hr-rate 111AH @ 100hr-rate
For any given lead acid battery, the quicker power is removed the less you get.
82 AH / 5 hours = 16.4 amps
100 AH / 20 hours = 5 amps
111 AH / 100 hours = 1.11 amps
So, if your draw is 5 amps then the battery could supply that for 20 hours. Draw 16 and the battery is dead after 5 hours. That is the value normally used when looking at RE systems as it is the closest to a 24 hour day.
~~~~~~~~~~~~~~~~~~~~~~~
using about 400 watts a day..
Some of you are not quite using the terms watts and amps correctly. It is not truly meaningful to say a device uses 400 watts a day. You need to phrase it as 400 watt/hours. That's similar to giving a battery capacity in amp/hours.
Going back to the OP...
Quoting: Dina95 Energy consumption: 123 kWh/year
123 kWh/year = 123000 watt/hours a year or about 337 watt/hours a day, average under the test conditions. So using a figure of 400 watt/hours a day is good, it provides some cushion for errors.
Learn to use the correct terms and, IMO, understanding will be easier.
|
|
Rossman
|
# Posted: 23 Jan 2013 12:07
Reply
Quoting: MtnDon So, if your draw is 5 amps then the battery could supply that for 20 hours. Draw 16 and the battery is dead after 5 hours. That is the value normally used when looking at RE systems as it is the closest to a 24 hour day.
Just reading this it's not really clear. To clarify, MtnDon is saying generally for renewable energy (RE) systems you will use the 20hr designation.
|
|
MtnDon
Member
|
# Posted: 23 Jan 2013 12:51 - Edited by: MtnDon
Reply
Yep. I did a poor job on editing that. Shame on me. Thanks.
|
|
Dina95
Member
|
# Posted: 23 Jan 2013 13:12
Reply
MtnDon, as i said, i am not really good at any of all these electronic things... I had to write a test in physics in my 2 year in highschool and I hardly got a 10/20!  
Anyway, (nobody answered the inverter question!  )
A fridge that uses about 400watts a day will need a 200 watt solar system (2 hours of sunshine) and around 400AH battery system...
Am i right?
and if i got it right, you mean that the battery i mensioned above will give me only 100AH (20hr rate), right?
And please someone, can you answer the inverter question?? ^^
Thank you guys for all the help you have provided to me!
You are amazing!!!
Also did i mensioned that i am young? (and a girl... i am not 18 yet but if i start from now my life will be much more easier! And i will save much more money to go shoppingggg, i love shoes )
Again, thank you a lott!!! Nobody else could provide me all this information!!! 
|
|
|
