Refigeration Amp Hour usage survey

[chala]

Originally Posted by a64pilot

I don't know which post,

Originally Posted by Richard Kollmann

reasonable control over condenser cooling medium’s

Just click on the little arrow just after Richard name.

Originally Posted by missourisailor

I think

More to do with maintaining design pressure.

[robert sailor]

Originally Posted by missourisailor

You are very correct on dirt and debris degrading the efficiency of any heat exchanger. The OP and others should always clean the heat exchanger before moving on.

But I find that most systems have a very piss poor, if any fan shroud/ducting system.
Most seem to have just a "pan cake" fan, ty-wrapped to the condenser. And at best, only 60%~70% of the condenser is seeing any air flow.

Just by moving the fan back an inch or so and constructing a shroud out of card board, generally does wonders.

But short of this, getting a fan that is the same size as the condenser, would be an improveme


--MAJOR THREAD DRIFT--

I have changed out many jugs due to heat related failures.
True, quite a bit of them have been due to loose, worn or even missing baffles <sp?>, but there have been those that failed because of pilot error due to improper cowl settings.
I was always told and taught, that the cowls were closed to reduce temp by slowing the air flow.
The Piper Tomahawk that I got my licenses in and the Aero Commanders, that were my bread and butter for many years, all were operated with the cowl vents partially closed after TO.

Locally we have a airline historical society that has what I think is the last AW (Air Worthy) "Connie". THey burnt up the first engine due to high CHT. The replacement engine was Zero'd timed, and it failed shortly after installation. Same thing, high CHT.

The official explanation was the cowl linkage was messed up.....But common knowledge among the A&P's was that the Chief Pilot had a standing rule that after climb out, all cowl flaps were to be 100% open. Okay for the other three, tired engines. With worn superchargers and turbo's. It was all they could do make TO power.
But the remaining engine, with it's new supercharger and the replacement engine with all new parts, had no problem making TO power. So cooling was much more critical.

I've been told that now, this engine's cowl vents now get moved to 75% after takeoff.
But, beings I have not personally worked on this plane, it is all secondhand info..

Doesn't make any sense to me

[missourisailor]

Originally Posted by chala

Just click on the little arrow just after Richard name.



More to do with maintaining design pressure.

I don't think that "design pressure" has anything to do with it. More like proper CFM over the entire condenser.

[missourisailor]

Originally Posted by robert sailor

Doesn't make any sense to me

I'm at a loss.
What doesn't make sense?
Proper air flow across the condenser or slowing the air flow down to allow more time for cly/head to air heat transfer?

[chala]

Originally Posted by missourisailor

I don't think that "design pressure" has anything to do with it.

It is a free world.

[ardoin]

Back to the original question...
BD50 unit (air cooled), about 8cuft spill over frig with a 12cuft freezer.
Frig stays at 38F at upper level and freezer stays at 22F at mid level in the summer.
Frig stays at 38F at upper level and freezer stays at 15F at mid level in the winter.
Power usage in the winter is 60AH per day and 110AH in the summer.
Original 3" insulation.
This is my largest power consumer since replacing the lights with LEDs. Good thing that I have 600AH of usable batt on my house bank

[SV THIRD DAY]

Originally Posted by ardoin

Back to the original question...
BD50 unit (air cooled), about 8cuft spill over frig with a 12cuft freezer.
Frig stays at 38F at upper level and freezer stays at 22F at mid level in the summer.
Frig stays at 38F at upper level and freezer stays at 15F at mid level in the winter.
Power usage in the winter is 60AH per day and 110AH in the summer.
Original 3" insulation.
This is my largest power consumer since replacing the lights with LEDs. Good thing that I have 600AH of usable batt on my house bank

Whew....them are some big boxes all right.
At that power usage, I'm estimating about 22hr of compressor run per day.

[ardoin]

About 40% run time in the winter and about 60% run time in the summer. So 40% of 24 hours / / 60% of 24 hours
Like I said, my biggest power consumer (since i upgraded my radar and halogen lights)

[ColdEH]

Originally Posted by typhoon

I just bought some . Main source for this stuff is eBay . Aspen aerogell . I have yet to do my doors but should have time soon to work with this stuff . R10 per inch ! Great !

Regards


Sent from my iPhone using Cruisers Sailing Forum

Just got back from a 2 week cruise around Prince Edward County and to Kingston On Canada .

It was a hot one , I think we broke many heat records up here. The fridge worked like a champ .

I got those new Areogell doors installed , 2" in each , top loading 8 cubic foot box .

Had a chance yesterday to do an amp hour check with the box closed all day , 1/4 full and the temperatures being an average 25 degrees Celsius.

Ready ....19 ah !!! actually 18. 875 to be exact. The Areogell in the doors really helped, the original build just had one inch of old foam , might as well had just left it open .

I saved myself 10 AH with this last improvement . I will reconfirm my results again this week , but I am very happy with anything under 30 ah daily .

Regards

[SV THIRD DAY]

Bingo..19AH for an 8CF box...there are those that will say that's impossible...ha ha ha...great job!

[ColdEH]

Hey Rich , I could hardly believe it myself ! I did the math twice and it looks to be spot on , I will run a test again this week. Must be that R12a I'm using . Runs at lower pressures .

Regards

[ColdEH]

Confirmed , ran the test again yesterday . 20 ah . The boat was warmer inside and a very sunny day . 34 inside and 30 outside Celsius . Again it must be that R12a refrigerant I'm using . They say it's somewhere around 35 percent more efficient. Seems to work just fine .

http://www.redtek.com/

The BD35 is only drawing 2.2 amps when running .

Regards



Sent from my iPhone using Cruisers Sailing Forum

[zboss]

Originally Posted by typhoon

Just got back from a 2 week cruise around Prince Edward County and to Kingston On Canada .

It was a hot one , I think we broke many heat records up here. The fridge worked like a champ .

I got those new Areogell doors installed , 2" in each , top loading 8 cubic foot box .

Had a chance yesterday to do an amp hour check with the box closed all day , 1/4 full and the temperatures being an average 25 degrees Celsius.

Ready ....19 ah !!! actually 18. 875 to be exact. The Areogell in the doors really helped, the original build just had one inch of old foam , might as well had just left it open .

I saved myself 10 AH with this last improvement . I will reconfirm my results again this week , but I am very happy with anything under 30 ah daily .

Regards

That's 8 CF of fridge not freezer... right?

[ColdEH]

Originally Posted by zboss

That's 8 CF of fridge not freezer... right?

Yes this is a fridge only , I am in the process of building the freezer condensing unit as I type this . My Bristol has separate cabinets for the fridge and freezer . I will start a thread on that build as soon as I get all the bits together .

Regards

[chala]

Originally Posted by a64pilot

You can't over cool a condenser.

Originally Posted by Richard Kollmann

A fan should only be operated as needed.

More info in the post.