Sanyo split for cooling a pantry?

System
System Posts: 2,511 admin
in Off Grid Solar & Battery Systems #1
Ok i am a newbie so be easy on me here.

I live in the wonderful hot and humid state of Florida. The wife and I want to build a walk in pantry (15x10)in the garage and are wondering if it would be feasable for the Sayno mini split system to act as a cooling source for the pantry.

The pantry would be needless to say insulated all the way around. For storing food we need at least to keep the area at least 70 degrees year round (colder in winter would be ok I guess). The total garage area now is about 400 sq ft.

I have seen 48vdc systems advertised on the web, but have yet to hear back from the "manufactures" of these systems. The whole DC to AC to DC system sounds for a better word wasteful.

Just looking for feedback postive or negative.

The whole system would need to be solar to help keep final (long term) cost down. Adding a second A/C system to the grid would not help this goal. Plus I figure with big enough system I could also add a chest freezer for additional storage.

Thanks.
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Comments

  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #2
    Re: Sanyo split for cooling a pantry?

    Why not grid tie your solar and then hook the mini and chest freezer to the grid. You get the benefit of gathering all your solar harvest against what would be less efficient system with batteries. one of the off gridders will pipe up here but batteries are less than 100 percent efficient. Battery systems are usually scaled for a 2-3 day run with poor harvest. The down side to that is you have to have a charging system large enough to bring them back up pretty rapidly but on several good days in a row you throw away your excess solar harvest.

    Since you don't have to buy batteries you will have more funds for panels and even scale your system larger to cover your normal house loads

    PS this is a prime example ofmwhat happens,to batteries
    http://forum.solar-electric.com/showthread.php?t=13676
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  • System2
    System2 Posts: 6,290 admin
    #3
    Re: Sanyo split for cooling a pantry?

    From I have read (could be wrong) if the grid goes down the solar sytem shuts of as well. And where I live power outages happen at least once a month. Granted its usually only a couple of hours, but I would rather not be worried about losing foods if the outage turns out to be longer.

    We haven't been hit with a hurricane that caused long term outages since 2004. But when that did happen here it was turned out to be weeks on end with no power.

    If that happens again we could always sleep in the pantry at night. Of course the pets wouldn't be happy, but we all have to sacrifice sometimes. :D
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #4
    Re: Sanyo split for cooling a pantry?

    SO if you are looking for a back up power system for occasional outages and longer term disaster , a generator is much more cost effective. LPG is a good storage medium with no aging issues unlike gasoline.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #5
    Re: Sanyo split for cooling a pantry?

    Define your off-grid/emergency needs (Watts Peak, kWH per day, seasons, etc.).

    Roughly (just as a starting point--your numbers will be different):
    • $0.10-$0.30 per kWH for Grid Power
    • $0.45 per kWH for Hybrid Power (solar+battery+GT/Off-Grid inverter)
    • $1.00-$2.00+ per kWH for Off Grid Solar Power
    • ~$1 per kWH for Generator Backup Power
    And everything hinges on properly sizing your system--And even before that, Conservation and defining your "emergency" loads... As you can see, it costs you around 10x at much for off grid power vs grid power--So for Solar/Generator, conservation is usually a huge win (before designing and installing your backup/off grid system).

    In line with sizing your system... your "base" load is critical... A 10 kW - 20 kW genset may consume from 0.5 to 2 gallons an hour -- with zero load.

    A 1,600 watt genset may consume around 1/10 to 1/4 gallon per hour (zero to full load). Run for 1/2 a day to keep fridge cool and lights in evening. 20 gallons of gasoline will keep me "happy" for ~10 days... Plus I have more in the car. Or I can use the 20 gallons in storage (fuel stabilizer + recycle to car once a year) to leave the area, if needed.

    There are also places that sell conversion kits to propane for smaller gensets. Or get a bit larger with propane, natural gas, or small diesel--Again, depending on your needs.

    Add a battery bank + inverter + backup charger and you can have "quiet power" in the evening/night (lights, radio, computer, etc.).

    Not trying to dissuade you from your project--but really trying to get a hold of your power needs (and what you have now) vs your end goals.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    #6
    Re: Sanyo split for cooling a pantry?

    My model of Sanyo, has an 'Auto' mode.
    http://ecorenovator.org/forum/geothermal/683-sanyo-24khs72-ac-hp-diy-install-project.html

    Once you set it to Auto mode, it will switch back and forth between
    cooling and heating, to hold your 70deg setting.

    One thing that I've noticed when using heat mode, if the sun comes in
    and heats up the house, the Sanyo will idle at 30 watts.. While the sun heats up the house.
    If I used Auto, the cooling would come on and try to fight the solar gain.. :roll:

    If your 15x10 room is tight and well insulated (with no windows), it should be very easy to keep at 70F.

    My 24,000 BTUh units only use about 460watts in their normal running mode.
    I would guess, that a 9,000 BTUh Sanyo (or other inverter type 17 SEER or better)
    would maintain 70F using a similar (or less) amount of power.
    Total daily use might average 2 to 3 kWhs.

    My two older model Sanyo systems are rated at 36,000 BTUh (6 tons total) of heating on mild (cool & rainy) days like today.
    (The average today was 53.8 deg F). http://pauland.net/daily.php
    It's really over-kill to have them both running! But, I'll only use about 4.8 kWh today..
    That's about like leaving a 200 watt light on 24 hours..

    My point is, these systems are so efficient, your pantry setup is going to use such a small amount of power,
    the (heat) losses in the PV inverter will not be very important. Due to the small scale of power use..

    Take 10% loss: (Seems like a lot, but it's likely more)..
    If it takes 220 PV watts into the inverter to deliver 200w to the mini-split,
    20watts x 24hours = 0.48 kWh of loss a day..?. At 21.6 cents per KWH, that's 10.3 cents of loss a day..
    Not enough to buy a small bag of peanuts.. :p

    Cheers,
    Rich

    PS:
    Both my Sanyo are using 30 to 60 watts total (it varies) to keep the crankcase oil warm.
    The smaller versions of this vintage Sanyo (18,000 & under) do not have a crankcase heater, so the standby power will likely be 5 or 10 watts.
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #7
    Re: Sanyo split for cooling a pantry?
    A 10 kW - 20 kW genset may consume from 0.5 to 2 gallons an hour -- with zero load.
    ...
    Add a battery bank + inverter + backup charger and you can have "quiet power" in the evening/night (lights, radio, computer, etc.).

    Mike220 - actually figure on about 1.5 gallons an hour at no load on the lower end of Bill's kw range. Lots of advantages to using NG or LPG, but low fuel consumption isn't one of them since the smallest you'll find is 6 kw (unless you convert a gasoline model).

    Genset plus inverter/batter for nightime and mid-day use is how my system operates. By using ultra-cheap high-capacity UPSs I have a huge battery bank with a total system cost of less than half of a similarly sized inverter with a much smaller battery. If you want more info let me know. Oh, and if you have a Prius there's another option (see my signature).
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #8
    Re: Sanyo split for cooling a pantry?

    Well, I agree with most of these points. I see the battery bank as an unseperable part of a solar system. the guy up the street went in to grid tied this year and beat his head on the wall when the power went out for 5 days a few weeks ago.

    What alot of people forget is when the sun is shining, an off grid setup is supplying power directly to the appliances/lights too, as well as charging the batteries, so the hit taken because of the charging of and discharging of the batteries is negated in daylight hours if you are running those appliances in daylight. At night (or in a grid failure event) those batteries are a godsend...:cool:

    So yes a small generator is a great addition. You can buy brand new Honda EU2000i's that run on LP from Central Maine Diesel for instance with a new product warranty to boot. But I really struggle to fault an off grid system if there is grid power in the home too. The losses on one running loads in the daylight hours are very minimal....
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #9
    Re: Sanyo split for cooling a pantry?

    I still think that for a grid home in a diaster a nat gas or LP generator make more sense. The cost and hassle to maintain the battery side for diaster use is just not worth it. In a diaster the fuel cost are a minimal consideration unless you are in diaster mode a high percentage of the time. Of course if a battery system is used then only critical load should be considered, but for a reasonable cost pretty much the grid can be replace completely with a generator, no need separate the critical loads. I know in AZ I would want to have my AC running most of the year.

    If solar is in the mix then a fair amount of harvest is lost in the battery system and those watts make more benefit for the owner in a grid tie system. Line up the money and do thie math, grid tie with battery back up is a losing option once the costs to implement are considered.

    PS this is a prime example of what happens to batteries
    http://forum.solar-electric.com/showthread.php?t=13676
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #10
    Re: Sanyo split for cooling a pantry?

    Yes, if you are home to dig out the genny, fuel it, check the oil, string out the cords, chain it from being stolen, get the earmuffs out and stay close enough to keep it running. All this at the moment the power goes out then a generator is a great solution.

    Otherwise let the power go out and your off grid devices will never know it happened. Devices like a coal stoker to heat your home that will go out in 2 minutes without power, freezers full of food....and you are off on a business trip or a weekend away.

    There is reliable and semi reliable, that choice needs to be made.

    And then there is the cost of that auto genny, transfer switch, fuel (to BB's example 20 gals at $3.5 = $70). That's a battery cost. A battery that will last for several years if well kept.... Moving parts maintenance for the genny's.....the stench.....the sound....

    As much as I love my genny, I loathe it as much...
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #11
    Re: Sanyo split for cooling a pantry?

    $70 worth of gas when I bought it at $3.50 a gallon--I will recycle it one year later at $4.00 per gallon --- a $10 return on my $70 investment. Better than I am doing anywhere else with my money. :cry:

    Also, a $70 6 volt @ 220 AH battery stores around 1,320 WH of energy (6v*220ah). That is somewhere around a 1/6 to 1/3 gallon of gasoline.

    So, in the end, for longer power outages, a person is going to need solar panels, a genset, backup utility power, etc. to recharge the $70 battery.

    Don't get me wrong, having reliable emergency/off grid power that does not rely on a genset and 1-2 weeks of stored fuel is great. But, it does come with a price ($$$) and limitations (generator plus fuel, easy to move in a car/pickup truck. Solar array bolted to home + a bunch of batteries, not so much).

    In any case, for emergency power/off grid use--knowing your power needs, conservation in choice of loads, and planning a system that meets those needs can be a big help in keeping the system small and cost effective.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #12
    Re: Sanyo split for cooling a pantry?

    Right Bill, but the battery will do it again and again and again. Yes solar panels are required to refuel it but those are required even with a grid tied system...still need a grid tie inverter for grid tied too. And that genny ain't free either I'm assuming.

    So the OP states that his grid is very suceptable to outages. "every month" is very suceptable and it should be derived that a long term outage is a distinct possibility in his area because of it. Unless his is willing to suffer the chances of long term outages with out moving from his home I still vote off-grid or atleast a hybrid system.

    How much is a KWH worth when the grid tied system is down? How efficient is producing electricity from a genset?

    Reliability...off-grid support in an on-grid home. In my honest opinion. I know this now having survived through 2 outages in the last couple years that lasted 5 - 7 days each and multiple outages (7?) that would have caused my heat to go out.

    Plus a genset/charger for just in case but I rarely use mine

    As far as I know, my charge controller is atleast %95 efficient and have measured my inverter at 91% to the best of my abilities....that ain't much waste during daylight operation. But I know one thing for dang sure, my off-grid system is far more efficient all night long than any grid tied or genset system is...
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  • System2
    System2 Posts: 6,290 admin
    #13
    Re: Sanyo split for cooling a pantry?

    Wow, thanks for all the opinions and inputs guys. Definately a wealth of information here.

    I originally looked at a grid tied system with a generator as a back up, but came to the concusion that it would have to be gas/diesel and would require constant refueling. Natural gas or propane is not a option with county regulations. (no where to put a decent size tank-which has to be set back from property lines, possable ignition sources and any openings into the house)

    So back to batteries being the primary and a generator being the back up as being the best off grid choice.

    My 1st step will be building the pantry itself and adding the HVAC system. After I complete that project I will be back asking a slew more questions and seeing how much more trouble I can get myself into.

    Again thanks for all the input.
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #14
    Re: Sanyo split for cooling a pantry?

    You get an autostart LP.nat gas one like this with transfer switch 12Kw.
    http://www.northerntool.com/shop/tools/product_200484428_200484428
    $3999
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #15
    Re: Sanyo split for cooling a pantry?

    Just so it does not look like Stevek and I have a fundamental disagreement...

    I agree the batteries are great for backup power and would love to have them for my GT system... But, as always, your needs are what will make the decision for you. Mine (appears to be) a grid that loses power for ~1 hour every two to three years (car into power pole type events).

    And my major power outage will be an earthquake (once every ~100 years or so).

    So, spending money on batteries that I may never use in an emergency for the next 20 years--hard to justify.

    Also, in an earthquake, if the structure is damaged, we have inspectors that are more than happy to red tag and mayors that will arrest owners if they even go into a home to remove personal property. Having an off-grid solar system attached to my home just has too many unknowns/drawbacks to make sense for my situation.

    Earthquakes, while they affect entire regions usually have very spotty damage footprints. Between the ground wave travels and reflections, types of soil, and specific building issues--It does not usually end up with a 100 sq miles of utter destruction--But just a few blocks here and there in the region.

    Also, if you are interested in a small backup generator / battery bank setup, Stevek's thread is a great read. Lots of technical details about what goes into the design:

    Question about battery charger selection with EU2000 generator

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #16
    Re: Sanyo split for cooling a pantry?

    Absolutely no disagreement Bill. As a matter of fact I have purposely stalked your posts over the years before I decided on anything at all. This forum is great in the fact that there are so many knowledgeable people from all across the spectrum of requirements and regions with special needs and desires.

    It's a cool place to call home.

    After I re-read my last post above it did sound tinged with argument and appeared to be addressed to Bill specifically. Not so. Just some strong debate for my choice is all and of course YMMV...:blush:
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #17
    Re: Sanyo split for cooling a pantry?

    Not a problem Steve... We don't do shades of gray here. :p;):D

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • TheBackRoads
    TheBackRoads Solar Expert Posts: 274 ✭✭
    #18
    Re: Sanyo split for cooling a pantry?

    I guess I'm not seeing the purpose of this project. What’s the need to keep an auxiliary pantry at 70 degrees...? I see extra freezers or refrigerators being more practical. Nothing that I store (dry items) in my pantry will go bad at say 80 degrees vs. keeping it at 70... If it was already stated, sorry, it’s been a crazy day...
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #19
    Re: Sanyo split for cooling a pantry?
    solar_dave wrote: »
    I still think that for a grid home in a diaster a nat gas or LP generator make more sense.

    Scratch NG if you are in an earthquake zone, lines can be broken (think about the '89 quake and all the fireballs around the city), or auto-cutoff valves can be triggered. For your day-to-day outages NG is fine, but stick wtih LPG if you want power after "the big one".
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #20
    Re: Sanyo split for cooling a pantry?
    SteveK wrote: »
    What alot of people forget is when the sun is shining, an off grid setup is supplying power directly to the appliances/lights too, as well as charging the batteries, so the hit taken because of the charging of and discharging of the batteries is negated in daylight hours if you are running those appliances in daylight.

    Yes and no. It isn't quite that simple in real-world use but you do have a point.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #21
    Re: Sanyo split for cooling a pantry?
    TheBackRoads wrote: »
    I guess I'm not seeing the purpose of this project. What’s the need to keep an auxiliary pantry at 70 degrees...? I see extra freezers or refrigerators being more practical. Nothing that I store (dry items) in my pantry will go bad at say 80 degrees vs. keeping it at 70... If it was already stated, sorry, it’s been a crazy day...

    I can't speak for the OP but in many instances long term food storage is in practice. Shelf lives of dry goods (wheat, rice, beans) and wet goods too can be extended just by lowering the temp 10F or so. Large temp swings are even more harmful. Basements are used but are pretty uncommon in FL

    We have a pantry in the basement at a fairly constant 55-65F, lucky us.
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  • thenderson4
    thenderson4 Registered Users Posts: 16 ✭✭
    #22
    Re: Sanyo split for cooling a pantry?

    I grin as I read the posts of all of you readers who do not live in a warm/hot HUMID location. I was looking up at the location of each one of you as I read it. When a reader does not understand why you would want to keep your pantry at 70 degrees, perhaps the value missing here is relative humindity. It is not the temperature of 70 that is important, but by keeping the temp at 70, the humidity is kept managable. No molding, dampess, sweating, etc. . . . .

    My friend in the Bahamas whose solar power system I am upgrading even keeps his garage cooled with a split system, only for dampness control.
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  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    #23
    Re: Sanyo split for cooling a pantry?
    thenderson4 wrote: »
    I grin as I read the posts of all of you readers who do not live in a warm/hot HUMID location. I was looking up at the location of each one of you as I read it. When a reader does not understand why you would want to keep your pantry at 70 degrees, perhaps the value missing here is relative humindity. It is not the temperature of 70 that is important, but by keeping the temp at 70, the humidity is kept managable. No molding, dampess, sweating, etc. . . . .

    My friend in the Bahamas whose solar power system I am upgrading even keeps his garage cooled with a split system, only for dampness control.


    My late Father-in-law once made us a pot of coffee, while I was visiting him
    in NewPort Richie. I took one slip and started gagging.
    The newly opened coffee can looked okay, but when I looked at the bottom,
    there was a large hole rusted in it! Inside under the coffee, was this large
    multi-colored mold-like thing growing.. It was the size of a large coffee mug..

    So, I completely understand the reason for protecting your can-goods down there..
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #24
    Re: Sanyo split for cooling a pantry?
    thenderson4 wrote: »
    I grin as I read the posts of all of you readers who do not live in a warm/hot HUMID location. I was looking up at the location of each one of you as I read it. When a reader does not understand why you would want to keep your pantry at 70 degrees, perhaps the value missing here is relative humindity. It is not the temperature of 70 that is important, but by keeping the temp at 70, the humidity is kept managable. No molding, dampess, sweating, etc. . . . .

    My friend in the Bahamas whose solar power system I am upgrading even keeps his garage cooled with a split system, only for dampness control.

    Yes well I thought you could create a dry 80F as well. I was going off of the OP's statement of wanting 70F specifically. I know a dry 80F is possible as well as a dang humid 70F.

    My Mitsubishi mini splits have 4 modes of operation. Heat, Cool, Auto and...Dehumidify. It seems the OP would have spec'd in a dehumidifier?

    The only reason we can keep metal in our basement is because of our heat pump water heater that takes about a gallon to 1.5 gallons out of the air down there per day in the summer. Let me tell you what, a very humid 65F is reality down there. The floors and walls will sweat profusely without the HPWH.

    Maybe a HPWH would be a better choice for the OP?
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  • SteveK
    SteveK Solar Expert Posts: 387 ✭✭
    #25
    Re: Sanyo split for cooling a pantry?

    Rich, that is disgusting....
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  • XRinger
    XRinger Solar Expert Posts: 529 ✭✭✭
    #26
    Re: Sanyo split for cooling a pantry?
    SteveK wrote: »
    Rich, that is disgusting....

    Yeah, it was bad stuff. He said afterwards, 'yeah, that did have an odd odor to it'..

    Even if it's pretty warm (75-80) outdoors, I find the Dehumidify mode on the living
    room Sanyo will not only keep the (whole house) air dry, but that constant condensation action of IDU coil, will cool the house quite a bit..
    Even with the fan running super slow, (can't hear it and can barely feel the breeze)
    it can still make it too chilly in here, at times..

    But, if it's hot out, we just set cooling mode at 22 or 23 C and enjoy.. :cool:

    I wanted this inverter technology for heating, but the cooling is El Supremo.. :D
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  • System2
    System2 Posts: 6,290 admin
    #27
    Re: Sanyo split for cooling a pantry?
    SteveK wrote: »
    Yes well I thought you could create a dry 80F as well. I was going off of the OP's statement of wanting 70F specifically. I know a dry 80F is possible as well as a dang humid 70F.

    My Mitsubishi mini splits have 4 modes of operation. Heat, Cool, Auto and...Dehumidify. It seems the OP would have spec'd in a dehumidifier?

    The only reason we can keep metal in our basement is because of our heat pump water heater that takes about a gallon to 1.5 gallons out of the air down there per day in the summer. Let me tell you what, a very humid 65F is reality down there. The floors and walls will sweat profusely without the HPWH.

    Maybe a HPWH would be a better choice for the OP?

    My bad, I would have assumed that people would realize that when storing most dry and canned foods that low tempatures and humidty is a must. Fluctuations in both do really bad things to foods.

    The wife and I are starting to grow and jar our own veggies so a cool and dry place to store them is going to be required. 70 degrees is actually the upper end of temps needed to keep long term goods. Colder is better but building a walk in cooler/freezer is not going to happen at a reasonable cost.
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