inverter to run old freezer after hurricane

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Re: grid tie inverter, but no grid, will it work?

Postby Hillhater » Wed Jul 26, 2017 6:04 pm

Make sure to keep the freezer FULL at all times...with anything like bottles of water or those freezer blocks..anything that does a phase change near freezing point. Then when the power is off the freezer stays cold longer.
As long as you use free power to freeze them initially, they will act as a cold energy store.
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Re: grid tie inverter, but no grid, will it work?

Postby amberwolf » Thu Jul 27, 2017 12:57 am

I keep the empty spaces of my refrigerator/freezer (upright type) and my deepfreeze (chest type) filled with the gel-type "cool-packs" that come in our fish orders at work. There's only a couple a week, but over the years it's quite a lot of them. :) When they break open I use the stuff inside to mix with my planting soil to help keep moisture in there.

Matt Gruber wrote:anytime i see more on trash day, i'll pick up good pieces for the sides.

If there are pet stores near you that carry fish, find out what day they get their shipments in. They probably come in styrofoam coolers that are tossed out. If they carry frozen rats/fishfood/etc they also probably get a box with sheets of styrofoam inside it.
Last edited by amberwolf on Thu Jul 27, 2017 1:02 am, edited 1 time in total. View post history.
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Re: grid tie inverter, but no grid, will it work?

Postby billvon » Thu Jul 27, 2017 2:13 pm

amberwolf wrote:If there are pet stores near you that carry fish, find out what day they get their shipments in. They probably come in styrofoam coolers that are tossed out. If they carry frozen rats/fishfood/etc they also probably get a box with sheets of styrofoam inside it.

Might be a downside to reusing dead-rat shipping containers to encircle food storage.
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Re: grid tie inverter, but no grid, will it work?

Postby amberwolf » Fri Jul 28, 2017 1:41 am

Why? All those frozen foods (rodents or otherwise) are
A) frozen solid (packed in dry ice)
B) individually sealed in plastic bags / bubblepacks.

Unless their ghosts come nibbling.... ;)
Last edited by amberwolf on Fri Jul 28, 2017 1:42 am, edited 1 time in total. View post history.
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Re: grid tie inverter, but no grid, will it work?

Postby Matt Gruber » Wed Aug 09, 2017 5:08 pm

Great reviews on this co.
$98 for 800w pure sine wave 24v input

http://www.ebay.com/itm/800W-Car-Power- ... 1438.l2649
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Re: grid tie inverter, but no grid, will it work?

Postby Matt Gruber » Fri Aug 11, 2017 7:18 am

amberwolf wrote:FWIW, if it's a chest-style freezer, then there are two methods I've seen for those to shed the heat from the compressor coils. One is in a rear-mounted/under-freezer mounted setup, and the other is built into all the side and front and rear surfaces.

If it's like the latter you can't add any insulation to those surfaces while it's actually running (but you can wrap it in blankets or any other thick insulation jacket, thicker the better, after power fails to help insulate it further, as long as you be sure to remove them when power comes back on. This could add a LOT of time to keep it cold inside).

If it's made like the former, you can add on styrofoam sheets to quite a thickness to all sides without exchanger coils, whatever's practical for the area it's in, and even put insulation under and over it if it's only a rear-mounted heat exchanger. Depending on how it's mounted a rear exchanger can even be moved away from the freezer a bit and add even more insulation between it and the freezer. This can all be done and still ahve it running with the insulation on it, and it will take much less power over time to keep the stuff cold inside it.

Did a test on the grid, with the room at 82F i used my IR gun to take temps, to look for improvement areas.
inside lowest temp: compressor temp: rear coil temp:
15min 24F ........................105F.....................109F
25 min 13F..........................124F...................112F
65 min 1F..........................159F....................112F(rear panel 97-99F)
case passes, 79-81F except for rear. 97-99F)
Inside shelf, above compressor FAILS- 4F warmer than side of comp. or anywhere else. will add styrofoam.
i replaced the old door seal, almost no leakage, maybe 1 degree at worst.
may try a 2 watt fan on the rear coil and another at compressor. may pull coil up off rear as that is a hot spot.
thanks for comments!
Last edited by Matt Gruber on Fri Aug 11, 2017 11:31 am, edited 2 times in total. View post history.
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Re: grid tie inverter, but no grid, will it work?

Postby Matt Gruber » Fri Aug 11, 2017 2:02 pm

OK here is what i did:
1. moved rear coil out 5" away. added 3/4" styrofoam against rear freezer wall.
2. added 1" styrofoam in compressor box.
3. 4" fan blows air in left front, it goes around comp. and exits right rear..
4. inside, put 2.5" styrofoam on top of shelf(comp under it)
.
Used 1 whole glue stick! LOL
anybody want to see another test tomorrow?
Last edited by Matt Gruber on Fri Aug 11, 2017 2:04 pm, edited 1 time in total. View post history.
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Re: grid tie inverter, but no grid, will it work?

Postby amberwolf » Sat Aug 12, 2017 1:25 am

Would be interesting to also see the difference in length of time it stays cold with and without the extra insulation. ;)
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Re: grid tie inverter, but no grid, will it work?

Postby Matt Gruber » Sun Aug 13, 2017 7:48 am

8-13-17 test #2 on grid AC
room 78, down from 82F
after 65 min, comp was only 107, down from 159! this is important as induction motors running on modified square wave inverters are said to use 20% more watts, creating more heat, risking overheating and failure. future test will use inverter and check heat.
rear coil 95, was 112.
rear top 79-81 down from97-99. added foam 82-87.
front-sides-top 74-76 was 79-81

inside -5 down from +1, except floor was as high as 38F :roll: and comp box side 17-18 top 0 need foam on floor and box side.
used wattmeter this time, 112w slowly dropped as low as 97, but popped up to 105 as i had lid open 2 minutes checking temps at test end.
everyone should own an IR gun! the food you save may be your own! LOL
.
edit
after 42 min OFF, floor was 47, most was 35. top comp 38. that floor is terrible. i thought cold air sinks and didn't check it last time. :oops:

edit2
just added 4" thick :shock: styro to bottom....17"x13" no more sneaky floor exit!
Last edited by Matt Gruber on Sun Aug 13, 2017 10:27 am, edited 5 times in total. View post history.
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Re: grid tie inverter, but no grid, will it work?

Postby Matt Gruber » Mon Aug 14, 2017 11:42 am

got some free GoBoard 1/2" backer board pieces, for under freezer.
put an ice cube between goboard and styrofoam.
10 minutes later go was the clear winner! did not want to melt the ice hardly at all after 10 minutes go was 75F nearly dry, and styro was 67F and dripping wet!
GoBoard is waterproof and passes fire code, unlike styro. and strong enough for floors!
specs:
http://www.jm.com/content/dam/jm/global ... struct.pdf
.
edit
put 1" of backer board on bottom(outside)
1/4" gap to floor
Last edited by Matt Gruber on Tue Aug 15, 2017 10:16 am, edited 1 time in total. View post history.
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