Engle Fridge/Freezer

[bgallinger]

My Engle MT-17 Freezer runs well at 2.5 amps, BUT it runs a lot to keep the freezer at 0 F. My numbers show the freezer compressor running 18 out of 24 hours. I purchased the bag they suggest, but I'm not sure if it helps much.
Is there some maintenance needed?
Has anyone added rigid insulation to the inside of the freezer? I would be happy to add an inch of insulation to the inside if it would help!

Cheers!

[Reefmagnet]

At 0 degree's Fahrenheit, 75% duty cycle probably isn't that bad. Aside from increasing insulation; ensuring the seals are ok and keeping the freezer as full of stuff as possible (even if that seems counter intuitive), there's probably not a lot that can be done to improve it without raising the minimum temperature.

[noelex 77]

The unusual swing compressor used in the Engel fridge/freezers has a low power draw,but this means that that the duty cycle is higher.

[OzeLouie]

Originally Posted by bgallinger

My Engle MT-17 Freezer runs well at 2.5 amps, BUT it runs a lot to keep the freezer at 0 F. My numbers show the freezer compressor running 18 out of 24 hours. I purchased the bag they suggest, but I'm not sure if it helps much.
Is there some maintenance needed?
Has anyone added rigid insulation to the inside of the freezer? I would be happy to add an inch of insulation to the inside if it would help!

Cheers!

Heat penetrates a cabinet in a rising fashion so heat through the base is the most critical. Try sitting the Engel on a 'bed' of sponge rubber say 30 to 50mm thick. That should reduce duty cycle.
Also suggest to locate the thermostat sensor which is the thing that looks like a piece of wire located unit end inside near the evaporator. Slide a piece of 'shrink wrap' over the end say 75 mm of the sensor or wrap with electrical tape. That will slow the sensor reaction to cause longer run and longer off periods to also improve efficiency.
Also should mention... make sure the warm air from the unit is not restricted or re-cycling...

Cheers Louie

[Richard Kollmann]

Originally Posted by bgallinger

My Engle MT-17 Freezer runs well at 2.5 amps, BUT it runs a lot to keep the freezer at 0 F. My numbers show the freezer compressor running 18 out of 24 hours. I purchased the bag they suggest, but I'm not sure if it helps much.
Is there some maintenance needed?
Has anyone added rigid insulation to the inside of the freezer? I would be happy to add an inch of insulation to the inside if it would help!

Cheers!

The condenser fan is too small when used as a freezer try a 50 or 60 Cfm fan held to outside of slotted area opening with tie raps to exhaust more heat. Also try raising thermostat to a freezer temp of +10 degrees F box temperature.

[Uncle Bob]

Originally Posted by bgallinger

My Engle MT-17 Freezer runs well at 2.5 amps, BUT it runs a lot to keep the freezer at 0 F. My numbers show the freezer compressor running 18 out of 24 hours. I purchased the bag they suggest, but I'm not sure if it helps much.
Is there some maintenance needed?
Has anyone added rigid insulation to the inside of the freezer? I would be happy to add an inch of insulation to the inside if it would help!

Cheers!

Hi, I have had an improvement in my freezer, a 40 litre unit, where I carefully cut a 10mm thick high density hiking matress to the size of the various panels and fitted them inside the cover. The panels need to overlap at the corners and no covering at the compressor vents, it is tight to fit the foam but I found that it is worth the effort.
When the unit has been running for a day or so putting your hand between the unit and the foam and then the foam and bag one can feel the temp difference.
Every bit helps.

[s/v Jedi]

I agree with Richard: improve condenser performance and increase freezer temperature. After much testing we switched to -14C which is about 7F.

If buying these units: Snomaster has more insulation.

Also, duty cycle should not go over 50% for Engel nor any other brand. If it gets worse, obviously something is wrong. If it’s always been like that, find out the reason and correct.

Heat -always- transfers in 3 ways: conduction, convection and radiation. All three must be addressed when looking at insulation.

[noelex 77]

You can download the performance data at various settings and temperatures for all the Engel models. This is the link for your MT-17:

https://cdn.shopify.com/s/files/1/03...f?v=1587146842

This is graph is just one example from the link. In an ambient temperature of 35C with the thermostat set at position 3, the temperature is arround -6C and the compressor will be running 78.6% of the time. There are several graphs showing the performance at different temperatures and settings.

You can see from details that the Engel's duty cycle approaches and reaches 100% in hot conditions and cold settings. These high duty cycles would be a cause for concern with most brands, but the Engel uses a unique design of compressor that is expected to operate at a higher duty cycle and can do so without damage. The swing design of the Engel compressor uses significantly less power than a normal compressor so despite these high duty cycles the power consumption is comparable.

[s/v Jedi]

Originally Posted by noelex 77

You can download the performance data at various settings and temperatures for all the Engel models. This is the link for your MT-17:

https://cdn.shopify.com/s/files/1/03...f?v=1587146842

This is graph is just one example from the link. In an ambient temperature of 35C with the thermostat set at position 3, the temperature is arround -6C and the compressor will be running 78.6% of the time. There are several graphs showing the performance at different temperatures and settings.

You can see from details that the Engel's duty cycle approaches and reaches 100% in hot conditions and cold settings. These high duty cycles would be a cause for concern with most brands, but the Engel uses a unique design of compressor that is expected to operate at a higher duty cycle and can do so without damage. The swing design of the Engel compressor uses significantly less power than a normal compressor so despite these high duty cycles the power consumption is comparable.

The Engel swing compressor is a beauty but that design was done to make it more durable than other compressors, not to run continuously. A 50% duty cycle should be attempted.

It is correct that it runs for almost 80% of the time at 35C room temperature, but it is not designed to be used in tropical temperatures and room temperature should not exceed 30C. At 30C it can maintain a duty cycle better than 50%. When it’s a hot day, over 30C and it runs more that day that’s fine, but it should not be the normal operating mode.

Below the page from the service manual, showing that operation in room temperature over 30C is outside design parameters.

[noelex 77]

Engel fridges are popular with the 4x4 enthusiasts in Australia. Typical air temperatures well above 30°C are very common on, especially when the Engel is frequently left in the vehicle. If the unit did not work in +40°C temperatures they would not have many Australian customers.

Engel publish the performance at a 45°C ambient temperature. In this air temperature they can still reach around -5°C. While they will freeze at these air temperatures, they will not reach their minimum temperature of -20°C and I think this is what the service manual is indicating.

The OP does not indicate the ambient temperatures when the duty cycle was 18/24, but at a setting of 0°F (-18°C) this type of duty cycle is common and does not necessarily indicate a problem or a fault.

[bgallinger]

The suggested temp for a freezer is 0 degrees F and I need a temp of 0 F to freeze ice cubes. The ambient temp is 70 F to 80F so that is nowhere near 30 C to 40 C. My numbers appear to co-relate to others stated in this thread, but I'm still a bit surprised at the duty cycle time.
Again, has anyone attempted to add insulation to the inside of the box? Surely it can't hurt!

[Bill O]

Fresh water actually freezes at/below 32F/0C. Try to reduce your temp to 10-15F and test how long it takes to make ice cubes.

This should dramatically reduce your duty cycle and still give you cubes.

Would only add insulation to the outside. If you add it to the inside (sides), it will block the coils from cooling/pulling heat from the inside of the box. Could possibly add it to the inside top and bottom where there are no coils. Obviously this will decrease the interior volume if you add foam to the inside of the box.

[noelex 77]

Originally Posted by bgallinger

The suggested temp for a freezer is 0 degrees F and I need a temp of 0 F to freeze ice cubes. The ambient temp is 70 F to 80F so that is nowhere near 30 C to 40 C. My numbers appear to co-relate to others stated in this thread, but I'm still a bit surprised at the duty cycle time.
Again, has anyone attempted to add insulation to the inside of the box? Surely it can't hurt!

So at 75°F (24°C) and a fridge temperature of 0°F (-18°C) you have a duty cycle of 18/24= 75%.

The closest table by the manufacturer is:
77°F (25°C) and a fridge temperature of -4°F (-20°C). Engel indicates the duty cycle at these settings should be 83.2% with an hour to reach temperature.

So while the manufacturer's data was not measured in exactly the same conditions, it is close enough and suggests your unit is performing as it should do (possibly even a little better).

As with any fridge anything you can do to improve the insulation will help reduce the power consumption, although I think this will have to be external. I suspect internal insulation would interfere with the fridge operation, but there are some very knowledgeable fridge experts on this forum who will provide a more definitive opinion.

[Marathon1150]

We keep our Engel at -10C. This temperature is 8 degrees warmer than the standard recommendation of -18C.

We can expect that quality and flavour of stored food will deteriorate more quickly at the warmer temperature but we don't keep anything in the freezer for more than about 4 weeks. The difference in quality and flavour is likely negligible over this period of time and there are energy and machine benefits that offset the slight difference. There is nearly zero risk that spoilage organisms can grow at this temperature (none are known but that doesn't mean that they don't exist).

And as noted in a previous post, ice cubes, a critical component of boat life, do not suffer at this temperature.

[s/v Jedi]

This may have been lost in the posts so I’ll repeat this: at a setting of -14C instead of -18C, we have noticed no difference of food quality when vacuum packed at 6 months frozen storage. At this setting your box will be closer to the 50% duty cycle that ensures lifespan as designed.