|
|
Post by rene460 on Oct 10, 2020 11:50:11 GMT
I am with Sailbleu on the suggestion of putting the fan on that hole in the floor of the compartment, but the next question is to look at how the air enters that underfloor compartment. On my small boat, the choices are limited as I have mentioned, you don’t want it to come from the warm area surrounding the hot water tank or battery charger. And preferably avoid the area against the hull above the waterline. You may need an extra vent into the floor area to ensure that you keep the temperature rise in the compartment to a minimum.
If the compartment door grate is not directly against one of the condensers, it might be worth making the door vent the inlet, and let it blow out through the paths it can find.
I wonder if you have an extra sensor available on your monitoring system that would allow you to monitor the temperature in that compressor compartment.
rene460
|
|
|
|
Post by Bora on Oct 10, 2020 12:21:19 GMT
I'll probably get another sensorpush sensor to put in that space, be interesting to see how the temperature correlates to the fridge temp.
|
|
|
|
Post by sailbleu on Oct 10, 2020 16:12:52 GMT
I'll probably get another sensorpush sensor to put in that space, be interesting to see how the temperature correlates to the fridge temp. Lowering the compartment temp will not lower the fridge temp. . That is the thermostate ‘s job . The compressor run no doubt will be shorter and so will the heat generated by compressor and condensor . That also contributes to a lower compartment temp. I can vouch for a lower energy consumption of the fridge when the cabine ( compressor compartment) temp is lower . Using my airco makes an enormous difference . Regards |
|
|
|
Post by Bora on Oct 10, 2020 16:15:41 GMT
The fridge was on maximum cooling, number 6, and it couldn’t get below 6 degrees sometimes even with the compressor running all the time.
I’m guessing if the coolant temperature can be brought down by increasing the airflow in the compartment then colder coolant will give me a cooler fridge and less run time.
|
|
|
|
Post by zaphod on Oct 10, 2020 20:21:03 GMT
The fridge was on maximum cooling, number 6, and it couldn’t get below 6 degrees sometimes even with the compressor running all the time. I’m guessing if the coolant temperature can be brought down by increasing the airflow in the compartment then colder coolant will give me a cooler fridge and less run time. It doesn't quite work that way. As long as the condenser is able to reject enough heat to fully condense the refrigerant into liquid you will get the full refrigerating effect. Subcooling the liquid refrigerant beyond that will not make any difference to the refrigerating capacity of the system or make the box colder. Having said that, If the compartment gets so hot that it cannot fully condense the refrigerant then you will experience lost capacity and higher amp draw on the compressor. A rough way to tell if this is happening is by checking the temperature of the liquid line coming out of the bottom of the condenser. It should not feel hot at all; slightly warm at most. Ideally an accurate measurement of the liquid line combined with discharge pressure is the best way to know exactly what is going on in the system. |
|
|
|
Post by sailbleu on Oct 11, 2020 6:23:06 GMT
The fridge was on maximum cooling, number 6, and it couldn’t get below 6 degrees sometimes even with the compressor running all the time. I’m guessing if the coolant temperature can be brought down by increasing the airflow in the compartment then colder coolant will give me a cooler fridge and less run time. It doesn't quite work that way. As long as the condenser is able to reject enough heat to fully condense the refrigerant into liquid you will get the full refrigerating effect. Subcooling the liquid refrigerant beyond that will not make any difference to the refrigerating capacity of the system or make the box colder. Having said that, If the compartment gets so hot that it cannot fully condense the refrigerant then you will experience lost capacity and higher amp draw on the compressor. A rough way to tell if this is happening is by checking the temperature of the liquid line coming out of the bottom of the condenser. It should not feel hot at all; slightly warm at most. Ideally an accurate measurement of the liquid line combined with discharge pressure is the best way to know exactly what is going on in the system. I suppose the technician checked all that . @ Bora , do you hear a distinct hissing from the evaporator ? Some evaporators get ( partially) blocked after awhile . Put a sensor in the freeze compartment , the evaporator in other words . That could give you an idea of the performance . But probably you are no longer in similar warm conditions as you were in the hot summer season . That makes it difficult to evaluate of course . Regards |
|
|
|
Post by Bora on Oct 11, 2020 6:47:15 GMT
The fridge was on maximum cooling, number 6, and it couldn’t get below 6 degrees sometimes even with the compressor running all the time. I’m guessing if the coolant temperature can be brought down by increasing the airflow in the compartment then colder coolant will give me a cooler fridge and less run time. It doesn't quite work that way. As long as the condenser is able to reject enough heat to fully condense the refrigerant into liquid you will get the full refrigerating effect. Subcooling the liquid refrigerant beyond that will not make any difference to the refrigerating capacity of the system or make the box colder. Having said that, If the compartment gets so hot that it cannot fully condense the refrigerant then you will experience lost capacity and higher amp draw on the compressor. A rough way to tell if this is happening is by checking the temperature of the liquid line coming out of the bottom of the condenser. It should not feel hot at all; slightly warm at most. Ideally an accurate measurement of the liquid line combined with discharge pressure is the best way to know exactly what is going on in the system. hats kinda what i meant but you explained it clearer  i'll have to check the lines next time onboard. |
|
|
|
Post by Bora on Oct 11, 2020 6:49:10 GMT
It doesn't quite work that way. As long as the condenser is able to reject enough heat to fully condense the refrigerant into liquid you will get the full refrigerating effect. Subcooling the liquid refrigerant beyond that will not make any difference to the refrigerating capacity of the system or make the box colder. Having said that, If the compartment gets so hot that it cannot fully condense the refrigerant then you will experience lost capacity and higher amp draw on the compressor. A rough way to tell if this is happening is by checking the temperature of the liquid line coming out of the bottom of the condenser. It should not feel hot at all; slightly warm at most. Ideally an accurate measurement of the liquid line combined with discharge pressure is the best way to know exactly what is going on in the system. I suppose the technician checked all that . @ Bora , do you hear a distinct hissing from the evaporator ? Some evaporators get ( partially) blocked after awhile . Put a sensor in the freeze compartment , the evaporator in other words . That could give you an idea of the performance . But probably you are no longer in similar warm conditions as you were in the hot summer season . That makes it difficult to evaluate of course . Regards Never noticed any noises other than a fan noise now and then. Will move the fridge sensor for the next round of testing. As you say it's going to be a while until i've got a 30 degree Croatian sun beating down on us. |
|
|
|
Post by sailbleu on Oct 11, 2020 8:18:08 GMT
To hear the hissing your ear has to be next to the evaporator of course . If it’s very faint you could have partial block that results in diminished cooling .
Regards
|
|
i'll have to check the lines next time onboard.