Author Topic: Chest freezer to fridge conversion  (Read 9757 times)

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Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #15 on: July 21, 2015, 01:47:50 am »
Been meaning to get these up, as well as the stray remaining pics... For now, graphs...

When I leave it alone and let it do it's own thing, it does rather well... The past week looks like this:

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The upper graph is pretty self explanatory... The only things to really mention is that the water sensor is near the supply, and the air sensor is right at the return. This appears to be a decent arrangement after lots of tinkering and what not... The other mention is yes, it operates centered on 0C, a normal household fridge typically runs higher. This is due to the difficulty of maintaining the two relatively close chambers at two rather different temps using nothing more than blower speed.

The "score" graph, simply put, is it's "EEG", a peek directly into it's brain. There are several influences on it's behavior, each of which gets normalized and then averaged. The result is the red line, which becomes one of the two master controls to start/stop the compressor.

The grey lines represent the "soft" limits, the upper being start, the lower being stop. Likewise in the main fridge plot, the water temp has hard limits; it is the only sensor that can override the rest. All 4 trip points are regularly hit during normal operation.

Explanation of the monitored data:

Scr.ToD: Time of Day. Derived solely from a simple sine function, it is used as a generic predictor for ambient heat, and tries to turn the compressor off in the afternoon, during peak heat of the day. Presently centered around 4PM, as there's additional lag caused by the thermal mass of the living space itself.

Scr.F_Water: Corresponds to the water bottle in the fridge chamber. Easiest to think of this as a zoomed in view of the space between the lines on the regular fridge plot. While this sensor has ultimate control, it also helps convince the brain if it's on the fence about starting or stopping.

Scr.Core: Based on the ice core temp. There is some extra math applied to this value that causes it to "speed up" as the core temp gets lower, essentially forming a knee in the score that suddenly tries to stop the compressor as the temp crosses the -12C mark. IOW, not a linear relationship like the rest of the inputs.

Scr.Power: Based on the battery SoC, currently set as upper=100%, lower=70%. I'm considering letting this one extend "beyond zero" so that when the batteries are lower than they should ever be, this value can ultimately stop compressor operation altogether by driving the average too low to ever start it. This value is also slated to be forced to 100 when the truck is connected to the grid or otherwise detects a non-renewable power source. Simple as it is, the "sensor" involved in this (a tricked out cell phone charger and an optocoupler) still hasn't made the finished list. I could have assembled and installed it in the time it took to explain this... I digress...  ::)

Scr.Amb: This design may be one of the few (only?) fridges ever to take user comfort into account when making run/stop decisions. Most of the time now this value stays at 0, but once in a while pops up when the room temp is low enough. The idea is simple, all else considered, if the room is on the warm side but the conditions in the fridge aren't desperate, put off running until it's cooler. It worked well during spring when the temps are all over the map, adding a little heat to the room when it's chilly, and holding off when it's warmer. Ultimately, the other sensors win out of course, and the value effectively becomes meaningless during summer.

Scr.Pyr: Pyranometer, telling the brain what the theoretically available power is from the sun at the moment. This input is presently represented by a simple "rectified" sine wave, and essentially "every day is sunny". This will be replaced by the input obtained from a "poor man's pyranometer"; a small PV string (think "large" yard light) dumped into an appropriate value resistor. The voltage that appears across the resistor can be used to approximate what can be expected of the main array. It's not perfect by the definition of "pyranometer" but will serve the requirements well enough for these purposes.

Scr.Boost: Last but not least, this too is derived from a sine wave, and can be thought of as the "master sync pulse" that tries to make the compressor start early in the morning. There is one pro and one major con to it's attributes... It helps dodge peak heat of the day by starting before the sun starts really warming things up,  but must be balanced with the idea that the compressor is starting when the batteries are theoretically at their most dire point. Its amplitude is such that on its own, it can't trigger a start unless it's already approaching it anyway, and essentially works in tandem with the pyranometer input to sway the actual start time.

This input is also associated with the transfer blower being disabled, causing the fridge chamber to begin to rise, further convincing it that it should start early in the morning if it's ok to do so. The blower remains disabled until first shut down. It then uses analog feedback to "pull coolth" into the fridge chamber as needed. In the event there is more than one compressor run in a day, the others aim at running as little as possible by turning the blower on full tilt while the compressor is on, so as to satisfy the needs while dumping as little heat as possible into an already hot living space.

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4218-3

During boost mode, it will toggle the blower on and off as necessary if additional load presents itself. These are today's plots, and actually, there was some manual override today as I actually wanted some of the extra heat for testing the battery cooling system, but the behavior is identical regardless. I had artificially set boost mode late in the day after having locked the compressor out until about noon. When it was subsequently unlocked, and later heavily loaded, the blower was modulated over the course of a few hours. The result is clearly visible here, as it "pulled" from the core in order to maintain regulation.

As you can see, it indeed has decent regulation when it's left alone (and even when it isn't, to a point... can anybody spot where else I screwed with it? LOL). It typically runs once a day, coasts the rest on the ice, and there's always a cold soda (when I remember to load it that is!)

Loading plays the biggest role in ultimately determining what it does when. How the load is placed also heavily affects operation. As a general rule, with 12oz soda cans only as a load, ~75% full is about optimum.

There are two "acceptable" methods to load it. One is what I refer to as "the twofer"... Take one can out, put 2 in. Obviously this requires observation of the total loading and attempting to maintain 75%. Until ASIMO comes to live with me, this task is likely going to be up to me to keep up with  ;D

The other is to "shock" it... allowing it to get down to about 50% load over the course of the day, and then replacing the "missing" 25% somewhere just before boost begins. When this method is used, it's generally best to disperse the new load as much as possible throughout the existing.

Also, a strategically placed warm can or two at one end and/or the other (supply vs return) can mean the difference between running or not, and requires some judgement.

All in all, it works very well... It doesn't perform quite as well as it did on "the bench", but then again, what does? LOL

I guess all that's left to be said about this one is that there are a few pics I want to post that haven't made it yet... Time is crunching, priorities shift constantly.

Oh, except one thing... I know someone will call me out on it LOL - There's plenty going on as far as the batteries go, however they are not only aging but are also only half the label capacity the finished design calls for... As a result, to minimize unnecessary stress on them, the fridge is being supplied from the grid at the moment. So if you thought the SoC score looked a bit off, it is indeed, and bonus points for catching that in that tangled mess  8)

Until next time...

Steve
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Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #16 on: April 01, 2016, 03:00:40 am »
Time for a very overdue update...

This is without a doubt the top of the list for most-everything in the sub-project category... It took a lot of time and patience, and as predicted, it absolutely had to be running on solar to be correctly fine tuned. Some things just really can't be properly emulated.

In the end, the entire score system had to be essentially completely rethought, which wouldn't be a first, but there really was no way to tell exactly what was needed while it was still bypassed to grid.

Just so happens that today catches just about every aspect of typical operation, so rather than snag and post individual plots, I just took screenies of the portion of the still rather primitive webapp that is used to observe/control it.

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They don't all fit on one screen, so here it is sectioned up starting at the top... In this shot, the vitals.


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This section is the final version of the brain, a bit different than originally envisioned...


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And here we have the "extras", for quick reference to assist in setting up the various triggers and factors that pertain to energy production, use, and storage.

I'm holding out on what's behind "button number manual"... the rest of the webapp being slated to be revealed in a special way, just for you guys... I did tell you, after all, that graph pool comes together in a sensible way... ;)

The vitals section hasn't really changed much, still reports the crucial info needed to know at a single glance what "state of charge" it's in, and the condenser temp thrown at the end of that because it was the best fit. It's used primarily to gauge thermal efficiency; deciphering such being more a black art than science really.

The decision system, as mentioned, was totally redone. My "score" idea was useful but I wasn't implementing it effectively to run on solar.

The score plot is still basically a set of weights and a balance, there's just less of them now, with most of the input being in the summing counterpart, "Pyro DSP". But before I go into that, a quick sentence or two about the remaining "score":

The two grey lines form the normal operation start and stop boundaries, start being on top. Green is an amplified and clipped version of "Pyro_Final_DSP" in the DSP plot. Black is a suppressed zero component representing the top 5% of battery SoC, and Red is the average of those two values. There's a third hidden value that never changes; it's the leftover remnants of the "user subjective" value... This is all delicate enough that for simplicity and expedience, I just tucked it away and hardcoded it in the software. This is what's responsible for the seemingly not-quite-average the astute eye might pick up on...

When red crosses the upper line, it initiates the compressor start sequence. Likewise, crossing the lower line shuts it down.

The source of the green line, the above mentioned "Pyranometer (DSP)" plot's final value, is somewhat complex in the way it's derived. First and foremost, the pyranometer is the basis of the entire signaling mechanism. This, in a nutshell, measures the available energy in the light hitting the panels, and while not a true pyro in the usual sense, it's close enough for all I needed it for, and that's strictly to cue the fridge. The light grey line ("Pyro_Raw") is the signal as the ADC sees it, and as you can see, can be very volatile. In order for this signal to be useful, it needs to be smoothed out somewhat, enter "Pyro_20_Min_Avg", in blue. This line is the "crystal ball" so to speak that attempts to give the algo a heads up about what the sky is likely to be doing next. It doesn't tell the future obviously, but uses the last 20 minutes (in 5 minute sample intervals) to pass trending light conditions to the decision system. This is a balance in the sense that if it's too short, the compressor cycles potentially unnecessarily, and if too long, can leave it running on battery, the primary condition the whole design is intended to avoid.

Next up is "Pyro_Boost", in green, which is kinda mislabeled, as it's function is to attempt to start the fridge early if the quality of the earliest light meets minimum criteria to do so. This is probably one of the most difficult entities to work out and set up... and only experimentation and observation over time with many different conditions presenting can properly configure it. This also isn't a static pulse. It is slid earlier and later based on a crucial but borrowed piece of code. Thanks goes out once again to Ross for helping me with this, math certainly isn't my strong suit and there's plenty of it going on in there. As mentioned earlier, this graph views primarily the summed weights, and this bump is added to the 20 minute average.

The last piece of magic in this puzzle is the magenta line, "SoC_DSP". Again, somewhat misnamed, it's also somewhat of a redundant input. It's purpose, when combined with the other battery SoC (in the score plot), is to encourage it to stay running when the battery has been recovered. The two weights serve slightly different purposes. This value effectively increases the perceived available energy, while the other is used primarily to keep the compressor running until it actually IS running on battery. This is essentially the boost pulse's counterpart for extending operation until the last available light of the day is gone.

As previously mentioned, all of the major features of the algo are visible in these two plots for today. The Boolean plots above the two control plots represent the various states of different aspects of the rest of the system. There's a lot happening there, but the keys that I'd like to really like to point out are the "Truck_Running" and "Fridge_Emergent"... the others are either low/no relevance to the fridge, or are fairly self explanatory.

The "Truck_Running" key is just what it says, the mystery for some is in the "why"... It might not have much actual effect on the compressor, but my thinking behind checking for this was to prevent excessive forces on the internal components of the compressor. I tried my best to reduce risks as much as I could given everything going on overall, this was one of them. I can't afford to replace the unit, even tho it wasn't that expensive really to start with (around 100 bucks at Lowe's). Nutshell version of "compressor 101"; the motor/compressor assembly is suspended by springs inside the black ball many of us are familiar with. I've personally seen that one mode of failure is the compressed side tubing leading back to the case breaking off, leading to a "running but not doing anything" unit. Bumps, gyro effects, etc. So the ultimate last piece of code in the software kills it no matter what (can't be manually overridden even) to protect it.

The other key worthy of mention at the moment is "Fridge_Emergent". Normally, the blower between chambers is disabled, and natural "pooling and spilling" is exploited to give the ice core the advantage during operation on solar. Aside from the truck running and manual operation, in auto mode it starts and stops by one of two sets of criteria. The above describes the normal cycle. It also is shut down when the fridge chamber gets too cold, presently set at -2.5C.

Fridge_Emergent however causes it to start when the fridge chamber gets too high (presently +5C), and runs the inter-chamber blower at full throttle, so as to drop the temp as quickly as possible and shut back down. It's very likely that if this condition occurs, everything is already short on energy supply, and it's just about certainly running on battery (again, this entire thing's point is to avoid that if at all possible). It keeps track of which trigger started it so that it knows which criteria should shut it down. This unfortunately induces an undesired behavior if the sun should come out, but it actually still remains an unverified function - it's never actually reached that point during operation since this was finalized. I've emulated it best I could without actually letting it "fall up" to temp. I may try it some day, as occasionally it does need defrosting, but in the mean time, I'll likely already be very aware that things have gotten to that point.

The blower, when the compressor is not running, operates via analog feedback, just as in the original design, attempting to hold the air/water temps just barely above freezing.

That's all I've got for now (Whew!). Until next time...
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Offline bj

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Re: Chest freezer to fridge conversion
« Reply #17 on: April 01, 2016, 08:15:27 am »
 I was wondering what you were up to,  and you've been busy.  Busy is good though.
"Even a blind squirrel will find an acorn once in a while"
bj

Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #18 on: April 01, 2016, 07:23:27 pm »
Yeppers busy for sure... tho the fridge has been pretty much matured now for a fair while... I haven't had time to really catch up on posting anything... I combed thru last night and looked, some of the stuff just completely left hanging, but this one had the most to report I guess. The scratch thread and chatting in IRC has given the subconscious illusion of updating for me apparently as well LOL.. I'm gonna try to play catch up, nothing else really has had major changes since January.

Steve
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Offline solarnewbee

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Re: Chest freezer to fridge conversion
« Reply #19 on: June 03, 2016, 09:32:14 pm »
Hey Steve Howdy!

Just read this thread top to bottom, nice! Love your troubleshooting techniques, we must be long lost brothers or something. HVAC and ACR can throw some weird crap my way sometimes.

3 questions:

1. How would glycol, simple as polypropylene 3350(available in the pharmacy), work out as an alternative to brine. maybe you could throw that experiment up here.

2. Ever thought about re-routing to a cold plate inside, sail boats use them without fans or controls of any kind (no controls, what fun would that be right?)

3. You substituted a 10mf in place of a 12mf that's a lot more than +/- 5% I assume it's humming right along just fine. most small appliances I repair use a 5mf, 3mf or nothing at all just relying on start relay. hmmm (the things that make you say hmmmm)

regards,

SN
SN

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Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #20 on: June 11, 2016, 05:41:16 am »
Hey Steve Howdy!

Just read this thread top to bottom, nice! Love your troubleshooting techniques, we must be long lost brothers or something. HVAC and ACR can throw some weird crap my way sometimes.

3 questions:

1. How would glycol, simple as polypropylene 3350(available in the pharmacy), work out as an alternative to brine. maybe you could throw that experiment up here.

2. Ever thought about re-routing to a cold plate inside, sail boats use them without fans or controls of any kind (no controls, what fun would that be right?)

3. You substituted a 10mf in place of a 12mf that's a lot more than +/- 5% I assume it's humming right along just fine. most small appliances I repair use a 5mf, 3mf or nothing at all just relying on start relay. hmmm (the things that make you say hmmmm)

regards,

SN

SN -

1. I'm not sure how the glycol mix would behave in this. I'd imagine the right mix ratio and temps and it could be made to behave similarly. The intent with the brine is 2 fold... First, it lowers the freezing (and therefore thawing and operating point) to well below 0C. Remember that the phase change is the most prominent feature of the storage medium being exploited. I don't want it to stay a liquid all the way to bottomed out (mechanical thermostat limit cutoff).

The second is more of a side benefit, as I'm finishing up now a "reserve gauge" that is based on a twisted averaging calculation to give a rough estimate of the percentage of ice in the core. It won't be perfect because of things like thermal impedance and not (yet) aware of thermal loading (eg changes in ambient temp and sudden loading of the fridge chamber)... however, because the temp continuously falls (and rises) without hitting the plateau associated with pure water, the amount of ice can be estimated on the average core temperature. As it freezes, the remaining brine gets more concentrated, requiring the temp to go lower and lower to completely freeze it (which doesn't quite happen with this combination (see the bottle showing the inch or so of brine that still remains on the first page).

2. I'm not entirely sure what you're referring to with that, but I can address the "controls" aspect of it... the reason this thing performs so well is because it's "brute force micro managed", if that makes any sense :o

3. Power factor correction for a "purely inductive load" such as an induction motor as found in a compressor follow a sine wave when you give several values for capacitance. 10uF isn't perfect, no, but it's only just barely starting to work it's way off the peak of the wave (which represents unity PF). 14uF would have a similar PF, just the current leading instead of the voltage as with the 10. Either way, actual measured PF with a kill a watt sees 0.98~0.99 with the 10uF... Still a very nice looking number compared to the much lower high 0.6 to mid 0.8 (depending on load... it's lower until the Freon pressures normalize) I was reading without it.

Also, don't mistake a start or run cap as a PFC cap. PFC caps are not connected the same way as the other two. PFC effectively goes across the mains feed at the motor. Start and run caps are part of an auxiliary winding that's used to cause phase shifting that makes the motor start and or run with the correct amount of slip. They will *affect* power factor, but the PFC cap is placed in *addition* to any start or run caps, and has nothing to do with the way the motor runs. They strictly control reactive power that otherwise gets lost as heat in the motor and upstream supply chain.

Hope this helped answer at least one of the questions ;)

Steve 
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Offline solarnewbee

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Re: Chest freezer to fridge conversion
« Reply #21 on: June 11, 2016, 11:51:00 am »
Hey Mad How are you!?

I see what your saying about the compressor cap and it's association with start and run. Most small btu compressors I deal with simply use the inductance relay to shift from start winding(some need a start cap for the kick ie., restaurant equipment I repair) to run winding without caps (small home appliance) and if I understand correctly from what your saying the cap on some I encounter is across the start and run terminals, Is that a phase shift or a compensation for power factor of the run windings? When I encounter a compressor that won't start and run and is tripping the external overload I will install what's called a 3-n-1 start run kit. It's electronic. has a start cap appropriate for the hp  and leads that slide right on where the relay and overload normally plug in.

As far as a cold plate is concerned it may not be as fun. it's a stainless box with and evaporator tube coiled inside and filled with non-toxic glycol. In your case it would be bolted inside the lid or to one side or even bottom of the freezer and connected to the refrigeration components by flexible lines. I had one for awhile but a friend has it in his sailboat now. fewer bells and whistles involved but it would be sized and temp controlled for freezing or cooling. some boats have them mounted to the side with a platform or basket made from thick plexi midway down for cooling and underneath for freezing. The whole idea is that the cold plate stays frozen for a long period and relieves the need for long running periods of refrigeration etc etc.

Thanks for the great info!

SN
SN

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Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #22 on: June 14, 2016, 02:02:14 am »
Hey Mad How are you!?

I see what your saying about the compressor cap and it's association with start and run. Most small btu compressors I deal with simply use the inductance relay to shift from start winding(some need a start cap for the kick ie., restaurant equipment I repair) to run winding without caps (small home appliance) and if I understand correctly from what your saying the cap on some I encounter is across the start and run terminals, Is that a phase shift or a compensation for power factor of the run windings? When I encounter a compressor that won't start and run and is tripping the external overload I will install what's called a 3-n-1 start run kit. It's electronic. has a start cap appropriate for the hp  and leads that slide right on where the relay and overload normally plug in.

When I was in HVAC, we called those "hard starters"... tho they're possibly slightly different going on your description alone. I know of one model that did away with the start cap entirely, and shorted it directly to hot (via a set of normally open current relay contacts). With no power applied, the start terminal only had the run cap across it (which depending on which compressor it was intended for, may or may not have had an augmenting cap included). When the contactor closes, the LRA pulled the start relay in, and connected the start terminal directly to hot (run), and upon reaching speed, the current would fall below holding threshold and the contacts would open, letting it run normally (or augmented as the case may have been).

Usually we'd determine if a hard start would be useful by the good old fashioned screwdriver test... Hold the screwdriver you opened the access panel with across the start and run terminals, and manually actuate the contactor, taking the screwdriver away a split second later. If it started, a BRB was all that was needed to get it running for at least the moment ;)

There are several variations of induction motor out there, but they all have 1 thing in common (in this context); they require some means of generating a "rotating field" in the stator. Normally a compressor motor achieves this by an auxiliary winding that's physically misaligned with the main winding, as well as being phase shifted (the job of primarily the run cap). The start cap serves more as a current limiter for the start winding in a correctly functioning motor, and while there's some phase shift associated with it, during start, it's mostly about providing the extra power needed to get the rotor spinning. A "hard start" takes this to the extreme by essentially allowing "unlimited" current to flow (only limited by the relatively low inductance of the winding). As such, further stress is placed on the motor... the compressors we'd install them on got tagged with nicknames like "the running dead" and such, as they might last thru a season in a pinch, but invariably indicated it's days were numbered (as you probably are aware). We would get the seasonal rush calls, install them for people that couldn't afford new condenser units right at that moment, and as stop gaps to reduce backlog for those who were in position to replace the units. Those usually saw a few units before they couldn't be accounted for or turned up dead themselves LOL We'd often reuse them (with the customers approval), offered up as freebies with the upcoming system replacement in mind.


Quote
As far as a cold plate is concerned it may not be as fun. it's a stainless box with and evaporator tube coiled inside and filled with non-toxic glycol. In your case it would be bolted inside the lid or to one side or even bottom of the freezer and connected to the refrigeration components by flexible lines. I had one for awhile but a friend has it in his sailboat now. fewer bells and whistles involved but it would be sized and temp controlled for freezing or cooling. some boats have them mounted to the side with a platform or basket made from thick plexi midway down for cooling and underneath for freezing. The whole idea is that the cold plate stays frozen for a long period and relieves the need for long running periods of refrigeration etc etc.

Sounds entirely viable... I've come to the conclusion that there are several ways to strike back at thermodynamics... I'm all about the ones that win! ;)

Steve
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Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #23 on: October 17, 2017, 04:42:20 am »
Went to toss a quick "by the way" at this, and realized it's been forever and there's been yet another major revision done to the algo... but I'm gonna have to come back to that... LOL... and as of once again shifting priorities back in the winter direction, I see another tweak to that involving what's below. What's that saying? Finished but never done?  :o ::) ;D

I'm not gonna make any bones about it, I drink a lot of friggin mt-du (I don't recommend it therefore I'm skipping shame-like plugging lol)... and in general, that's what you'll find the fridge keeping cool. There are reasons for that particular selection, most of which are well outside the scope of this thread, and even this one sorta is, but I figure since it's involved in a rather direct way, I'd put it in the fridge thread...

One of the things I use it for is auxiliary heat. And if I time things right, I can get a lot of bang for my buck. Last winter I burned ~25 gallons of propane total... This year I'm determined to get that number under 20, and 16 is the goal I'd just be tickled with.

Timing however is only part of it... there are several other ways to manipulate and optimize the fridge's role in heat supply during winter, and arrangement of the loading patterns is one of them.

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This go round, I let it mostly empty out, trying to coincide my consumption, running, and loading for "empty + cold front + 'depleted' core", so that I could fire it off in the middle of the night for a couple hours and have it pump a lot of heat very efficiently.

Pulled the last cold can out, and then fanned out the next case as seen above, combined with the transfer blower forced to full throttle, and that's exactly what she does.

Here in a bit I'll grab the ambient temp graph and show the results, but wanted to get this part of the story up and posted for the time being.
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Offline MadScientist267

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Re: Chest freezer to fridge conversion
« Reply #24 on: October 18, 2017, 06:57:38 pm »
Ok it's hard to get an "all else equal" view of thermal data of course, but the run I was originally going to grab didn't illustrate it really well... I noticed that today that the effects of both the propane and the fridge are rather predominantly and independently visible, particularly in the change rate plot...

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I decided that's probably the best view because it shows the relative timing and influence of the sun, but it's obvious where the main propane burner was both started and stopped... And while the fridge doesn't have super obvious start and stop points visible there because it "fades in and out", it's pretty clear just how much effect it can have.

To that end, I'm including the condenser temp plot to show its timing more explicitly. Note this subsystem uses CV (continuously variable) fans, hence the steady operating temp and "fading" effect it has on the space heating.



Not a bad system for winter... Just wish I'd have had time during the build to come up with a better way to deal with this extra heat in the summer... it's hard to cram all of this into a 14' truck... all I can say there lol

Til next time...
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Re: Chest freezer to fridge conversion
« Reply #25 on: October 20, 2017, 07:30:36 pm »
I'll call this an addendum to the above...

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Here's as close as I could get to "all else equal". Held off on running the fridge at all today to grab this so the differences would be more apparent.

I'll add that in both scenarios, the pilot for the heater was on the entire time (I've brushed on the effects of that elsewhere) - In the environment I've got going here, non-trivial effects in itself.

The blip on the outside at about 5PM is engine heat from a run up to the store.
Wanted: Schrödinger's cat, dead and alive.