Mini dorm fridge on inverter discussion

[Sugarkryptonite]

Hi guys

I have a van I am currently building. I've taken on the challenge of installing a mini dorm fridge as I wanted more capacity for a much cheaper price (compared to 12v fridges and 12v chest style fridges/coolers). Yes I know they're not as efficient (although debatable with real world testing from other threads), etc.

I have read many threads about people doing this with relays to turn the inverter on and off to save energy, but one thing I can't seem to get past is inverters that beep each time they are turned on. For those of you that are running a similar system, doesn't it drive you insane?

I will be sleeping in my van and don't want my inverter beeping every time it is turned on. I've tried a couple different pure sinewave models on Amazon and they all seem to beep when switched on.

Any advice from other people who have done it? Just keep looking for other inverters?

 

[time2roll]

My GoPower inverter does not beep.

Are you sure the beep is not from temporary overload? Those little fridges have a large start surge.

 

[Sugarkryptonite]

My GoPower inverter does not beep.

Thanks! A bit expensive for my blood, though.

 

[Crowz]

Pop the top on the inverter and axe the speaker

 

[Sugarkryptonite]

Pop the top on the inverter and axe the speaker

Yeah that is plan B

 

[z_zk_z]

Your question isn't clear "relays to turn the inverter on and off to save energy". The compressor of a refrigerator makes noise. The newer refrigerators based on inverter technology (nothing to do with a power inverter) make less noise and have less in-rush current. A refrigerator uses energy to keep its inside temperature at certain value and that energy consumption increases when you keep opening its door, and/or placing something hot that needs to be cooled. I have an LG refrigerator (LG LTNC11121V 11.1 Cu. Ft) which uses 33 watts in each hour (according to my power monitoring gadget), and that is not much at all. A single server type 100AH 48-V battery (~5000 W-H) can power my refrigerator for five months (assuming 100% efficiency). A refrigerator doesn't run continuously and it only comes on when it needs to keep its inside temperature at the set value, so it is already doing its on/off. I purchased my LG because of its "LoDecibel Quiet Operation". I can sleep next to it but the compressor of most refrigerators isn't quiet. I am not sure if you want to take a power converter (which also consumes power itself) and add relays to it in order to turn-off the refrigerator which needs to stay-on in order to do its cooling function. PS. I also have this Victron inverter which makes no noise and uses very little power itself ( https://signaturesolar.com/phoenix-inverter-48-1200-120v-ve-direct-nema-gfci/ )

 

[Sugarkryptonite]

Your question isn't clear "relays to turn the inverter on and off to save energy". The compressor of a refrigerator makes noise. The newer refrigerators based on inverter technology (nothing to do with a power inverter) make less noise and have less in-rush current. A refrigerator uses energy to keep its inside temperature at certain value and that energy consumption increases when you keep opening its door, and/or placing something hot that needs to be cooled. I have an LG refrigerator (LG LTNC11121V 11.1 Cu. Ft) which uses 33 watts in each hour (according to my power monitoring gadget), and that is not much at all. A single server type 100AH 48-V battery (~5000 W-H) can power my refrigerator for five months (assuming 100% efficiency). A refrigerator doesn't run continuously and it only comes on when it needs to keep its inside temperature at the set value, so it is already doing its on/off. I purchased my LG because of its "LoDecibel Quiet Operation". I can sleep next to it but the compressor of most refrigerators isn't quiet. I am not sure if you want to take a power converter (which also consumes power itself) and add relays to it in order to turn-off the refrigerator which needs to stay-on in order to do its cooling function. PS. I also have this Victron inverter which makes no noise and uses very little power itself ( https://signaturesolar.com/phoenix-inverter-48-1200-120v-ve-direct-nema-gfci/ )

Hi there

I think you missed the point of my objective. Firstly, you are right in saying those new LG fridges with inverter compressors are very energy efficient. Way too big for my van build, though. Where space is limited, a small fridge is all that can fit. I haven't come across a dorm style mini fridge with an inverter compressor, probably because it simply is not needed. My fridge draws 0.8 amps at 120v, I guess from a manufacturer standpoint, there is no point to making it an inverter for such an already-low power unit, and the price would be much too high for their competition, which in the mini fridge market is pretty competitive.

The relay is not used to turn the fridge on or off, it is merely used in conjunction with the temperature sensor inside the fridge (which is a simple switch) to turn my 12v to 120v inverter on and off, thus reducing the amount of energy consumed from it being idle when I am not actively using it for other things. My inverter uses roughly 1.5 amps, so up to 37.5 Ah per day, which is quite a significant amount. Toggling it on and off significantly reduces this. I am mobile in a van with a 400Ah battery bank, not in a house with 120v receptacles nearby.

This has been done by many people in the past. You can read this lengthy thread for details if you're interested with all wiring diagrams and power measurements taken comparing between a 12v compressor fridge and a 120v dorm fridge conversion like I am doing. In the end, from their conclusions, it's a wash between the two for power consumption, even with the inverter losses, and usually you get more space with a mini dorm style fridge.

DIY: How to make your own 12V Fridge

bcbullet, which model of grape solar is this? I can only find one on amazon atm it's 5 cu/ft and there are no tech specs anywhere, the model is GS-UF-5-Fab one Glacier

vanlivingforum.com