Fridges for buses

[joeblack5]

In every build ...econline van....Econoline ambulance...Econoline school bus..transit bus we have gone for SC fridges and freezers.. Domestic ..norcold..all based on danfoss bd35 compressors. Can't get more efficient. On graiglist between $50 and $150. Is what I paid for them. They are smaller in general ..often used on sailing boats...and can be made more efficient by adding insulation to the side , top and bottom.

Johan

[gs1949]

"To counter your second, dramatic paragraph, my personal choice may be likewise briefly summarized:
Bought. And. Paid for.."


I second that. It runs in my family. We're just selling a house that my dad started building in 1953, and finally finished sometime around 1990. They did the whole thing on the pay as they went plan. They never borrowed any money to do it. It's a cool house. We had it sold but the state doesn't like the septic system. There was no such thing as septic inspection. People just did it. But there is now.

I know I can build an interesting and fairly unique bus paying for it as I go along. But I know it won't be quick.

[john61ct]

The newer "Danfoss" (now Secop) BD50 has a bit more oomph, and the newer controller boards are always improving, variable speed and TXV tech make for very effective units even up to larger sizes, say 7cf.

Insulation is really the key, building a custom box using an awkward corner of the living space, with a "spillover" design to get both freezer and fridge sections from one compressor can work very well.

But the conversion kits aren't cheap, just getting a matching pair of say Engel or Indel-B portables, so either or both can be used as a freezer, is I think the best value long-term.

[OrionsComfortBus]

On YouTube are videos of fridge conversions of fridges.One shows a ammonia fridge being converted to a compressor freon cooled unit. Another shows a 110 Vac being converted to a 12 Vdc by swapping compressors. Used units of both types can by bought for a bargain. Add in a little elbow grease with a few parts and you can have a good working rv sized fridge. Of course swapping a compressor requires cutting copper pipe, silver soldering, applying a vacuum and filling with freon. Compressor swap fridge must already use r134a freon.

The ammonia swap is much simpler. No cutting of pipes and the compressor replacement is a single sealed unit.

JC Refrigeration is the website for the ammonia to freon swap.

[Rivetboy]

Originally Posted by o1marc

I heard more cons about propane to make me want one. I have a 10cf 120v fridge running off the inverter. It uses very little ah. And was a whole lot cheaper than the propane ones I checked out.

Hey Marc, How many AH day at what temp and which refrigerator is it?

[Rivetboy]

Temprature being outside air

[o1marc]

Originally Posted by Rivetboy

Hey Marc, How many AH day at what temp and which refrigerator is it?

I bought the Magic Chef 10.1cf from HD. I ran it a couple of days on the Kill-A-Watt. It averaged .014kwh, when the compressor kicks on it jumps to .50kwh. It sat at the front of the open gargage, so it saw 90+ a good amount of time. Mine is Black.

https://www.homedepot.com/p/Magic-Ch...00WE/302245066

[john61ct]

Originally Posted by o1marc

I bought the Magic Chef 10.1cf from HD. I ran it a couple of days on the Kill-A-Watt. It averaged .014kwh, when the compressor kicks on it jumps to .50kwh. It sat at the front of the open gargage, so it saw 90+ a good amount of time. Mine is Black.

https://www.homedepot.com/p/Magic-Ch...00WE/302245066

kWh is a unit for energy, consumed over a period of time, or stored in a battery.

Same as Ah but independent of voltage.

For instantaneous measurement, watts or kW show the energy flow rate, like amps but again, independent of voltage.

So, my 12V compressor fridge usually pulls an average of around 3.5A in hot weather in fridge mode.

I got that by counting coulombs with a DC version of the killawatt over 48hours, and getting an average of 3.5 Ah per hour consumption. At 12V that's about 42Wh per hour or a kW per 24 hours.

That is also 84Ah drawn from my deep cycle bank, so you can see refrigeration is not a trivial load when living off-grid.

However just looking at amps, it can fluctuate from half an amp up to 6 or 8A depending on conditions at the moment.

I hope this example help illustrate the proper use of these units in measuring energy consumption, or even inputs from charge sources.

[Ronnie]

I am useing a 4.7 cu ft fridge from Lowes. 120 volt ac running off the inverter.It pulls about 5amps measured on the dc side of the inverter when the compressor is running. I have 400 watts of solar, and 220 ah of batteries. No sun for three days is about the limit and have to recharge or find sun. If sunny for even part of a day I have enough to never need shore power. The interior lights, water pump, and vent fans are all 12 volt and run off the same solar and batteries.

We do have a norcold propane fridge in our old camper. Sometimes the flame goes out when driving, the "chimney" does soot up and need cleaning as does the burner several times a year. And I did have a flashback once lighting it that well kind of cooked some hair.... It is not an awful way to keep food cool, but nowhere near as reliable as a regular electric fridge.

I am not saying this is the best by any means the way I did my setup, however it does work well for me.

[gs1949]

So 220 AH is the nominal rating of your batteries then? Or is that what's available?

[Ronnie]

Originally Posted by gs1949

So 220 AH is the nominal rating of your batteries then? Or is that what's available?

Nominal rating of my batteries. I have 4 optima batteries each with a 55 ah rating.

[john61ct]

Pretty sub-par for true deep cycling usage. But not to worry, just do your research before they need replacing, could well last a few more years depending how they're treated.

[Ronnie]

Originally Posted by john61ct

Pretty sub-par for true deep cycling usage. But not to worry, just do your research before they need replacing, could well last a few more years depending how they're treated.

Sub par in what way? Not challenging you just asking for more info.

[john61ct]

When the spiral wound AGM technology was developed by Enersys and they created Optimums, it was a much better quality product than in recent years since they sold the brand off to JCI.

JCI makes no batteries I'm aware of that I'd call true deep cycling.

https://marinehowto.com/what-is-a-deep-cycle-battery/

Lifeline, Odyssey, Northstar all make excellent AGM batteries for that purpose, assuming you're in NA.

But not as good value as old-school FLA if that can be made to work for you.

The best battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

Otherwise avoid big box retail or automotive channels, do not order online, call the mfg for an outlet local to you.

[o1marc]

Originally Posted by john61ct

When the spiral wound AGM technology was developed by Enersys and they created Optimums, it was a much better quality product than in recent years since they sold the brand off to JCI.

JCI makes no batteries I'm aware of that I'd call true deep cycling.

https://marinehowto.com/what-is-a-deep-cycle-battery/

Lifeline, Odyssey, Northstar all make excellent AGM batteries for that purpose, assuming you're in NA.

But not as good value as old-school FLA if that can be made to work for you.

The best battery value by far is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

Otherwise avoid big box retail or automotive channels, do not order online, call the mfg for an outlet local to you.

I was surprised to see the ones I bought are Interstate batteries made specifically for CostCo. They are 6v-215ah.

[gs1949]

I've been looking at Duracell: https://www.batteriesplus.com/productdetails/SLIGC115

OR: https://www.batteriesplus.com/productdetails/sli6v225s

I'm leaning toward the first one because they're smaller and with some minor reworking I can fit 2 of them in the OEM battery compartment with the 2 6 volt starting batteries that are already in there.

That is, if I can trust the drawer glide type mechanism the starting batteries sit on with the extra weight. But if I decide I can't trust the OEM battery compartment with the extra 131 pounds and I have to put the new batteries somewhere else, then I might as well get the larger 250 Ah that are just a little too long to fit in the battery compartment.

[o1marc]

Originally Posted by gs1949

I've been looking at Duracell: https://www.batteriesplus.com/productdetails/SLIGC115

OR: https://www.batteriesplus.com/productdetails/sli6v225s

I'm leaning toward the first one because they're smaller and with some minor reworking I can fit 2 of them in the OEM battery compartment with the starting batteries.

That is, if I can trust the drawer glide type mechanism the starting batteries sit on with the extra weight. But if I decided I can't trust the OEM battery compartment with the extra 131 pounds, then I might as well get the larger 250 Ah that are just a little too long to fit in the battery compartment.

The CostCo battery was $98/$15 core charge.

[gs1949]

There's no CostCo around here. I assume that's because we're too underpopulated. Not sure how far it is to the closest one. Never cared enough to find out.

[john61ct]

Originally Posted by o1marc

I was surprised to see the ones I bought are Interstate batteries made specifically for CostCo. They are 6v-215ah.

Yes Interstate does not make their own, mostly outsourced to JCI, meh.

The Duracell/EPMs sold at Sam's & B+ will last a lot longer, everything else being equal.

[john61ct]

Originally Posted by gs1949

I've been looking at Duracell: https://www.batteriesplus.com/productdetails/SLIGC115

OR: https://www.batteriesplus.com/productdetails/sli6v225s

I'm leaning toward the first one because they're smaller and with some minor reworking I can fit 2 of them in the OEM battery compartment with the 2 6 volt starting batteries that are already in there.

That is, if I can trust the drawer glide type mechanism the starting batteries sit on with the extra weight. But if I decide I can't trust the OEM battery compartment with the extra 131 pounds and I have to put the new batteries somewhere else, then I might as well get the larger 250 Ah that are just a little too long to fit in the battery compartment.

Either will serve you very well. If a Sam's is nearby, check their pricing.

That big one will break your back!