Frequently Asked Questions

Common Topics


+ You have got to be kidding. No way it will be as efficient as a "real refrigeration unit."


Our original efficiency claims were based on an earlier study done by University of Georgia on cooler efficiency (that study has nothing to do with CoolBot it was just looking at where the energy use is in Walk-In's and they found that it was not the compressor as much as the fans). If you just think about the number of fans operating in a standard reefer unit (4-6 that are on ALL the time inside and an extra 1-2 outside) vs. the number in operation in a window a/c unit (there's just one and it doesn't have to be running all the time if you are in 'Energy Saver' mode) there's an immediate reduction in electricity use right there that is very significant. Obviously in both cases we are running similar sized compressors (in fact we up-size the compressors for CoolBot installations so there is actually somewhat of an energy penalty if you JUST looked at compressor use) but the penalty is very small and the savings from the fans is HUGE, so there is an obvious net gain).

Several customers that had "conventional" walk-in units and replaced them with a CoolBot in the same physical box report a significant drop in their electric consumption. You can find this by googling around - one guy reports that he ditched his old walk-in compressor, TRIPLED the size of his cooler, and is running the same electric bill. The problem is that all these (wonderfully positive!) reports have their cooler electricity mixed in with their other electrical usage so it doesn't really give us an exact percentage number - just that "things are much better."

We've only had a few people report in where they could actually tell us how much they saved. The savings are HUGE (like 60%+ energy) savings but... the units that the CoolBot replaced were really old and probably not made or running very efficiently, so we look GREAT in comparison, but what if you compared us to a modern new compressor -- can it really be that much more efficient?

NYSERDA, (the NY State Energy Research and Development Authority) contracted for an independent analysis to see just how much more efficient the CoolBot is than a standard cooler. We were hopeful that FINALLY we would get an exact answer to this question.

The 35 page NYSERDA study confirms that the CoolBot works great and does not stress out the air conditioner or push it into unacceptable use cycles or pressures (which is another question that we get asked a lot) so that was nice. And... the end result of the summary is that the YES! CoolBot is more efficient than a conventional walk-in cooler. HOWEVER, this study was NOT done with a real walk-in cooler and a real CoolBot-air conditioner!! It was done with a modeling program on a whole-house air conditioner that uses a different compressor type and two fan motors (instead of one), so... it's not really as useful as we would have liked (we wanted them to just measure watts spent on two comparable coolers).

I know we shouldn't be complaining, but... even though we "won", we didn't win by much at all and it was only because of fan cycling. We don't feel like it's a fair study because the comparison was with a whole house air conditioner with a different style of compressor and multiple fan motors - change any of those factors and our own calculations are back to us being 25% more efficient at minimum compared to conventional modern walk-in units. Still, we are really grateful for this study, and we agree they carried it out in an independent and logical way. But... we're still waiting for someone to do a real-world side-by-side comparison!!

+ Is the CoolBot just a thermostat? Does the CoolBot include a thermostat?

The CoolBot is NOT just a thermostat! Check out the short "How It Works" section. And yes, the CoolBot does include a digital thermostat so you can set it to run at whatever temperature you want (down to 32 degrees).

+ Does the CoolBot REALLY run down to 32 degrees without freezing up?

We cover this at length in the "Who should NOT buy a CoolBot" portion of the website, but to summarize: A CoolBot system will NEVER freeze up, BUT it can not always be able to get you down to 32 degrees! If your door is being opened and closed a lot, 32 degrees is impossible (for us) to reach!! This is a problem with the physics of the small fan and transfer surface area in air conditioners. A conventional walk-in cooler compressor can do it, but a CoolBot can NOT!

Really, anything below 36F becomes difficult for the CoolBot to reach if fresh hot material is being put in the cooler and it's being opened and closed more than once every 10 minutes. We have hundreds of customers happily using CoolBots at 33-34 degrees, but it works because they open the doors only a few times a day. (Bars and pubs for example with secondary coolers or keg coolers that might be plumbed in). It's super easy for the CoolBot to cool down to 38 degrees and even 36-37 are not hard with normal use (but again, it's a stretch if you are opening and closing the door more often than every 10 minutes.)

+I NEED HEAT IN THE WINTER. I need to cool my room, but I am running into the winter and if it gets TOO cold outside, I need to be able to HEAT the room also. Does the CoolBot take care of this? Also, I noticed that there are air conditioners advertised that cool AND heat. Is that a better choice for me?

Okay, to answer your winter, cold question: What we do on our farm (we also require heating in the winter) is buy a little $12 space heater (not a radiant heater, only use one of one of the ones that *blows* hot air - that's important!) They are like $10-12 from Target or Walmart.

We plug it into a pass-through thermostat (you can buy them at This is the one I like: DuroStatâ„¢ Portable Waterproof Prewired Thermostat Item# CR2045... it's about $52.00. Make sure you choose one that can be set for BELOW 40 degrees F!

There are cheaper ones (for $34) but then you have to wire them yourself (which is actually really easy... we just cut an extension cord in half and screwed it in and then caulked the holes)... which I'm not recommending because I'm not an electrician.

And another product that some of our customers have used (and is very popular among the micro-brew folks, and there are even videos about wiring it up and it's well under $20 is this one (I have not personally used this, so I can't provide a review or any tech support, but people seem to love it and it's cheap!)

Whatever you choose. We set the CoolBot 5-7 degrees warmer than the heater (so they don't overlap and fight with each other).

The little space heater barely has to run to keep the room warm. It does NOT dry out the air (I think because it runs for so little time...just a few minutes per hour in total).

Usually in the winter, the amount of moisture in the air is so small that we don't have trouble with ice forming in the back evaporator pans of the air conditioners but it IS something to be aware of and watch for. For example, we had a farmer call one winter after a stretch of weather where it was warm and foggy-moist and then the temperatures CRASHED down... He woke up the next morning to clack-clack-clacketing because his fan was hitting the ice that formed over night! It had never happened before. He was so afraid the fan would be cracked but fortunately it was fine. He used a hair dryer to melt the ice and drilled a hole in the bottom of the evaporator fan for "next time" there was a stretch of weather like that, and I think that was a good idea. We talked about adding a a strip of "heat tape" (like you wrap around water pipes to keep from freezing) but in his case it didn't turn out to be necessary.

We don't recommend the "heating and cooling" air conditioners because they are so much more expensive than normal air conditioners. ALSO (the ones I've seen so far) aren't even automatic!!! So you have to set it to cool mode or heat mode... which is bad if you live in a place that has cold NIGHTS and warmer DAYS.

+I see the CoolBot is usually mounted next to the air conditioner, could I put it outside?

You can, but you really should NOT. If there is a troubleshooting issue, you have to have the CoolBot and air conditioner right next to each other.

If it's an issue of wanting to know the temperature from outside, there are pretty cheap ($19) wireless temperature sensors you can get from Amazon -- we've regularly seen them on sale for $12 from WalMart/Home Depot, and more expensive ones ($80) you can monitor on a smartphone or online.

Also: CoolBots can't be in direct sun, so if you still decide to mount it outside, you'd have to protect from that as well.

+Do you ship CoolBots internationally?

Yes! CoolBots ALL ship with international power supplies so they run on all voltages with no transformer needed. CoolBots can display in either C or F.

While window A/Cs are common most in the US, many users internationally prefer to buy "Split" or "Mini-Split" air conditioners. The CoolBot works great on split-type air conditioners and they are more energy efficient.

The CoolBot works perfectly with ALL known mini-split air conditioners. If you are concerned about how the CoolBot will run with a particular brand of air conditioner, please provide a web-link to the manufacturer including the model number, BTU's, and preferably a picture or link to the manufacturers brochure online and we can check it out. So far there have been NO mini-splits that do not work perfectly with the CoolBot.

Please email us if we can answer any other questions about international shipping!

+Can you connect me to someone using a CoolBot in my area?

When we first started CoolBot in 2006 we were really active about connecting people, but it's been 8 years now and we have over 18,000 installations so there are multiple people near you in every state using a CoolBot and we don't share customer names anymore for privacy and management reasons.

HOWEVER: We have a large testimonials page where people have posted about their experiences using CoolBots on:

  • Farms
  • Florists
  • Breweries - home brew and we add at least one new commercial micro-brewery every week!
  • Wineries
  • Hunting [google around for multiple forums discussing how great the CoolBot is]
  • Commercial/USDA Inspected Meat processing operations
  • Mobile Applications including trailers, vans, small box trucks and commercial fishing and oyster boats
  • Mortuaries
  • and more!

We also have links to online and print articles about the CoolBot on our NEWS Page.

Finally, we're also actively recommended by multiple land grand colleges and the USAID program in coolers large and small. In fact quite a few universities as well as NASA's SATOP program have contributed plans and support to CoolBot including some financial cost-share programs for small farmers who want to buy CoolBots to save money.

+Is it possible to power my cooler off the grid? Are there alternative power options?

Yes! There are options and we have people using solar power, the issue is, it's expensive because of the inverters and batteries. (The inverter is the thing that converts the electricity from the solar powered dc to the standard air conditioner ac power.) The a/c can do it, but the cost of batteries makes it five times the amount of a standard grid set-up.

For folks who are using solar power, the key is keeping the cooler as small and tight as possible.

Other options could be to run them on extension cords out in the field, or generators while waiting for battery technology to get cheaper. Our extension cord was 600 ft. on the farm! Not that that is ideal, but it's possible!

We're happy to help with any specific information for any one who wants to do it.

+Is it possible to extend a sensor?

Sure! There are a couple options:

  1. Buy an extender from RadioShack (the smaller the better, some of them have caused false error codes periodically, others have worked fine...also, make sure it fits in the store, some of them look like they should work, but then they don't... it's weird.)
  2. You can just splice in a little more "stranded wire" using very light gauge wire and wire nuts. Anything even as small as 24 gauge wire is probably fine for just 3 feet.

    Strangely: the higher the number, the smaller the wire diameter. You can go bigger... but you shouldn't go "smaller" than 24... so smaller would be 26, or 28... that would NOT be good.... But you can go BIGGER than 24... and bigger would be anything that is (ironically) a SMALLER number than 24 gauge! At HomeDepot 16 gauge wire costs maybe... 10 cents a foot? Numbers SMALLER than 16 (which means higher numbers) are even cheaper!

Stranded wire can be bought from HomeDepot, RadioShack, you could use speaker wire you have lying around... automotive wire... ANYTHING. Just cut the sensor wire in half and splice it in and you'll be set!

We don't void the warranty on the CoolBot for cutting up sensor cables.

We do void the warranty on the sensor cable that you cut, obviously... but it doesn't hurt anything as long as they are nice connections.

Air Conditioner

+ What size air conditioner should I buy?

We have a sizing and brand recommendation chart available on our A/C Size and Brand Recommendations Page but to figure this out for sure, it depends on a lot of factors.

Click here to fill out our form and we will get back to you with the best size for your cooler.

+ Will the CoolBot reduce the lifespan of my air conditioner compared to running it in a house?

Absolutely NOT! It seems too good to be true, but not if you think about it!

In our house in Southern NY, we have an air conditioner in the living room set to 70 degrees which we turn on when outside temperatures hit 80 (because the sun is streaming through our west-facing windows it gets hotter inside!) That's only a 10 degree temperature differential, but the air conditioner compressor is running 80-90% of the time because cold air is constantly spilling into the hall and the other rooms of the house and the heat gain through the windows is a lot. It cycles off sometimes, but a few minutes later it cycles right back on again (because there is no insulation or doors to keep that cold in place.)

Contrast this with our CoolBot Cooler, which is set to 38F degrees and it is regularly 90F out here. That's a 52 degree temperature differential! WOW! But the CoolBot controlled air conditioner runs only about 10 minutes of every hour. The reason is that the room is small (11x17 inside), TIGHT and well insulated! There is no leakage, or heat gain from windows! Now... obviously when we load up a couple tons of field-hot watermelons... the air conditioner is running like it does in our house. Same when we have to open the door a lot to load in new produce. But once things cool down again (which is fast), it goes back to the 10 minutes per hour holding run time.

+ Would the thermostatic control on the air conditioner be operational and accurate when the CoolBot device is installed?

No. It doesn't need to be because the CoolBot has it's own digital thermostat with dual temperature sensors. You just use that instead of the thermostat on your a/c unit. The CoolBot thermostat can be set to from 32-60F degrees (see above note that 32-35F degrees is hard to achieve unless you've oversized the air conditioner and aren't opening the door a lot).

+Can I run in Energy Saver Mode?

You can definitely change to Energy Saver mode on the air conditioner. There are things to consider...

UPSIDES of running Energy Saver Mode:

  • Saves Electricity
  • The fan turns off when the compressor turns off
  • (It will cycle on even without the compressor every 3 minutes for 30 seconds or so to circulate air in the room)


  • The room recovers from door openings more slowly
  • It cools down field-hot produce more slowly -- depends on how much you are loading up... some people don't notice or don't care... if you load up a lot of stuff, you should switch you settings back to "d1" (see below for instructions) and out of "Energy Saver" but if it's just a small amount... maybe it doesn't matter

If you do decide to put it on Energy Saver, you need to change the HEATER Delay setting up to "d3" from the default of "d1".

To do that, do the following:

  1. Use the RIGHT arrow to go into "heater" mode (the light under "heater" will be on, and "F" will be in the display if you are in the US, "C" if you are elsewhere)
  2. Press the CHECK MARK button 3 times (or until you see "d1" blinking in the display)
  3. Press the right arrow to change to "d3"
  4. Press the Check mark... that's it! The display reverts back to normal in 20 seconds.
+I saw that you recommend 12,000 BTU for an 8x8 room, could I upsize 1 or 2 or 3 levels (to 15,000, 18,000 or 24,000 BTU's)?

YES! Absolutely! (You shouldn't if you only want to be at warmer temperatures like 46F or above). For normal refrigeration temperatures, besides cooling down WAY faster and being able to get colder than 37/38F if you want, you'll actually SAVE MONEY in the long run even though you coughed up more cash for a larger air conditioner up front.

For example, our recommendation for an 8x8 room is 12,000 BTU's...

  • If you bumped up ONE or TWO levels you'd be at 15,000 BTU's or 18,000 BTU's. In both cases, you get MORE surface area to transfer cold, so you can run in Energy Saver mode most of the time (it's best to run in standard mode an hour before and after loading up). That will easily save you $15/month, which over a couple years will have more than paid for the extra cost of the air conditioner. 15,000 BTU's is good, and 18,000 BTU's is even better.
  • If you wanted to go up THREE levels to 24,000 BTU's you wouldn't save more money in electricity, but you could drop the temperature even FASTER and could go even colder.

ALSO: 18,000 and 24,000 BTU air conditioners both run on 220 volts. That means you have less amps running on each leg of your power cord, so you can do longer runs with smaller gauge wire and your compressor runs more smoothly.

+ Can I use a multi-zone split system?

Yes! You can. There are a couple folks using multi-zone mini split systems with the CoolBot.

We just need to be sure the outdoor compressor is able to accommodate the BTU needs for all zones. For example, if your walk in cooler needed an 18,000 BTU unit, and there were 3 other units that handled 8,000 BTU each, then we would need an outdoor compressor that was able to handle 42,000 BTUs.

+ Should I get the highest SEER or EER? What about an Inverter Vs. Non-Inverter?

Don't bother getting an a/c with the highest SEER or EER.

Just get an a/c with 13 SEERS and you will be set.

Inverter's are listed at 20-24 which is awesome and amazing for air conditioners being used to cool you house to 65-70. They are so much more efficient and save energy and are good for the environment.

In CoolBot systems, this does not apply. For what we are doing, at these lower temperatures the benefits do not carry over. The CoolBot is so efficient that there is not a noticeable difference.

We just did a comparison for someone in Mexico with the help of a neat program made by University of California for measuring electricity use and I was so surprised to see that the actual dollars saved between the inverter and non-inverter model are so small that it doesn't pay for the extra expense of the inverter model for 15+ years.

It's not that the inverter model isn't more efficient, it's that the cost of the running this per month is already so low that what looks like a really significant PERCENTAGE is actually very small in dollars per month. Not only that, but the way we cycle things on and off while we do make use of the efficiencies of the inverter technology somewhat, it's not as awesome as it could be because of the nature of what we are trying to do in terms of temperature goals.


+Can I use the CoolBot and an air conditioner in a mobile application? Truck, trailer, boat?

Yes! We have over 1000 mobile applications running CoolBots, on trucks, vans, box trucks, slide-in units in the back of pick-up trucks, boats and trailers. We've learned a lot over 9 years of mobile applications. Here's the GOOD, the BAD and then Critical "technique".


  1. We were worried about the window type air conditioners not holding up to running over the road but they are running great, and the first ones went in in 2007. We even have boat application with people crashing through waves on commercial fishing and oyster boats and STILL no problem -- the same units have been running for years!
  2. When people insulate well (a lot of them don't in mobile applications). It works great -- this is a big issue for us. People are trying to save every inch in their vehicles, so they often don't insulate well, or they don't insulate the floor of the vehicle and COLD SINKS... so then we have trouble until they insulate them correctly. See techniques, below.
  3. We are super cheap and robust compared to other mobile cooling solutions.
  4. You can run off the alternator on your vehicle IF you buy a 12,000 BTU air conditioner or smaller and an inverter (which can limit the size of your application or how cold you can get. For spaces up to 8x6 that are VERY well insulated, you should be able to hold 38F.) Otherwise it makes more sense to use a generator. More on this in the "BAD" section -- and inverter information in the "HOW TO" section.


  1. A lot of people want to use RV air conditioners which we don't love for the following reasons:
    1. They are REALLY expensive per BTU -- especially when you try to find one with a digital display. Dometic makes the original "BRISK" RV air conditioner which is digital... they have a sleeker looking one that is more expensive called the "Penguin" that's actually NOT as good for this application. So get the cheaper one (it's bigger on top which gives us more surface area to play with).
    2. They are annoying to set up, because you are working over your head and up in a hole AND you can't see what you are doing... so it's hard to put our FIN sensor into place correctly and worse yet, if it falls our or ices over... you won't know unless you look with a mirror and flashlight.
    3. Because of the VERY limited area that they are sucking and blowing out of (14x14) there is a BTU-transfer penalty of almost 30%... so... you buy a 15,000 BTU unit, but it only puts out 10-11,000 BTU's of cold! Which makes them even more ridiculously overpriced.
    4. For all these reasons... even in vans, it's not so easy to get below 40F with an RV air conditioner.... In smaller spaces... maybe, yes... but... it's just weirdly harder than with a window unit which is of course SUPER easy to work with.
  2. NC State has really detailed instructions on how to build a mobile cooler (the Pak N' Cool) with a CoolBot including mounting a window air conditioner in the side of a trailer... other people do this on vans and trucks as well (using window units). RV units are NOT as common. To learn more, click here to read about Mobile Cooler Construction
  3. We are not a great choice for people that need big mobile spaces cooler (like big box trucks) that run while they are driving because it's too expensive to run off your alternator and an inverter with bigger than a 12,000 BTU air conditioner. The people running larger trailers (we have people running 20 foot trailers on CoolBots) generally run on GENERATORS and then 24,000 BTU air conditioner.


  • For mobile applications we only recommend POLYISOCYANURATE rigid foam insulation OR spray foam (or a combination)
  • This is available in Lowes and Home Depot -- so it's super easy to get! It's kind of yellowish slightly... NOT the bright white stuff. That's EPS. That's bad. Polyisocynaurate has the highest r value per inch. Shoot for at least R 20 if you are going down to 38F it has foil on one side. The foil has to always face the "hot" side.

  • Don't bother with Radiantec(or other brands) bubble foil insulation if you are doing the foil with polyisocyanurate. It's extraneous
  • DO use Urethane spray foam like "Great Stuff"... NOT the latex version... that way you can cut the pieces and then catch the gaps with the Great Stuff. NC State's article an video demonstrates this really well.
  • Some people hire a spray foam installer to spray insulation in. Sometimes they tell you that they have amazing r-values per inch. They have just under r7 at BEST. so... make sure they do at least 3 inches if you go that route.
  • You can use spray ADHESIVE/glue to hold rigid foam insulation in place... We use "3M high strength 90" adhesive which is freaky strong and available at Home Depot and Lowes and probably Amazon.
  • Don't forget to insulate the floor! Cold sinks.
  • If you want to run off your alternator and an inverter, you have to use an air conditioner that is 12,000 BTU's or less. That's fine for even smaller trucks. If you go bigger than that, even on larger vehicles, you have to UPSIZE your alternator (expensive) and upsize your inverter into non-commodity inverters that are tons more money. 12,000 BTU's can limit how cold your space is... Many people that have big box trucks or trailers instead switch to generators.
  • We really like the TRIPPLITE heavy duty inverters. They are a bit more expensive than some other brands, but we think they are terrific. You can buy them in many places... here's a link to Amazon: TRIPPLITE heavy duty inverter
  • In general you want an inverter that can surge to *at least* THREE TIMES the running watts that are listed on the air conditioner box (or the sticker on the side of the air conditioner). Other cheaper inverters definitely work for people. This one is just a bit more "heavy duty" which is nice if you'll be running it for a long time.
  • If the generator and A/C are too closely matched, and there is barely enough power for the initial surge, you can get a hard start capacitor. We recently had a florist in Tampa report back on his experience and he said it worked great, was easy to install and highly recommended being certain you are connecting the wires to the compressor and not the fan. Follow the wires back if you have to. Once installed he said it was running just fine. His unit was picked up from a local home repair store for just over 20 dollars.

For more information on mobile coolers, check out our page.

+Will this work cooling meat?

Yes! We now have thousands of meat folks including over 100 small commercial meat processing facilities using CoolBots. Most of our meat folks are a few hunters who got together and invested in one. Obviously you have to size the a/c unit to the size of your walk-in cooler box as per our chart AND you have a walk-in cooler built to industry standard specifications (4" of styrofoam insulation in walls/floor/ceiling.) If you meet those requirements, the CoolBot will keep whatever your want (produce, flowers, meat, prepared food, dead bodies in mortuaries) at whatever you set it at down to 33 degrees F.

What the CoolBot can NOT do is:

  • Keep things frozen
  • Keep things cold when you have a substandard cooler or too small of an air conditioner.

I think because our units are so inexpensive, a surprising number of people try to approach the rest of the structure in an inexpensive way, too, so they build coolers with standard fiberglas-house insulation or even just use it to try to cool an uninsulated storage room. It won't work! The fiberglass actually DOES work for awhile, but outside humidity condenses in the walls making the insulation sag and filling it with mold and mildew. So... use the thousands of dollars you save buying a CoolBot to insulate your cooler with styrofoam insulation (it's not THAT expensive!) We sell to a lot of hunters and hunting camps as well as people who make hamburgers and other meat-containing prepared foods and they have been very happy with the performance of the CoolBot.

For more information on coolers for hunters and meat processors, check out our page: Hunters and Meat Processors

+ Will this work to cool my flowers?

Yes! Thousands of florists use the CoolBots to keep their flowers cool, and we're recommended by the American Society of Cut Flower Growers (and we were tweeted about as an option by a company in Europe with 9700 affiliated florists called Euroflorist.).

You don't have to, but we suggest upsizing from our chart for a couple of reasons:

  1. Most florists prefer to run at a lower fan speed because it means less wind on the flowers. In order to run at a lower fan speed, you want to increase the surface area you are transferring the cold from, so that means upsizing by one level.
  2. Often florists use display coolers with windows and they are VERY lossy, so consider sizing up (a second level!) if you are running with glass doors or display windows.

The cost of upsizing is just tens of dollars and you will have this for many, many years.

Note: MOST all the florists are running in high fan mode without a problem because air conditioners already blow less hard than conventional walk-in coolers. One woman did make a deflector (just out of cardboard) because she had a small cooler and she wanted the air to go just up towards the ceiling (it was blowing RIGHT ON the flowers on the shelf across from it otherwise). That worked great. If you are building from scratch, though, consider the placement of your a/c unit when you install it so that it is blowing in a safer direction without the deflector (again, it worked perfectly). You always want to blow the LONG way down the room if it's a rectangle.

We also get asked sometimes if the air conditioner will dry out the flowers.

It will NOT so long as you aren't blowing RIGHT on the flowers. Thanks to the wonders of physics, the relative humidity in a CoolBot controlled room will be PERFECT for cut flowers whether you are in Arizona or Louisiana. (In AZ, the relative humidity will be HIGHER inside the cooler than outside, as appropriate for flowers, in LA, the humidity will be LOWER inside the cooler than outside, as appropriate for flowers!) We didn't plan it this way, it just works! Yay physics!

Sometimes people don't believe us, and ask if they CAN use humidifiers in their rooms with the cut flowers. Sure! It won't effect the CoolBot or the air conditioner at all. *But you don't need it* and the fact that it encourages and facilitates disease in the cold room means you really shouldn't. If you want to do some quick spritzing on especially sensitive flowers that seem to be getting a bit more air flower than others, then go ahead. Otherwise, it's not necessary.

For more information on use of the CoolBot for your flower cooler, see our page: Flowers

+Is the CoolBot NSF approved? Will the CoolBot work in a restaurant applications? Commercial Kitchens?

There aren't any NSF certified air conditioners, so no one that has air conditioners in their commercial kitchens have them NSF certified. There are NSF certified walk-in cooler PANELS. You can check with your local department to find out if that's necessary.

We are running in thousands of inspected commercial kitchens and inspected meat processing operations with no problem. Many people also build their own coolers and use FRP panels on the inside, for example: or whatever is stocked locally in your area. Even Home Depot and Lowes seem to have them now.

In the last year we've only had a few calls from people who had trouble with local inspectors and CoolBots, and we were able to work them out.

One was from an inspector who was NOT concerned that the air conditioner was not NSF certified (because she allowed air conditioners in the commercial kitchen already) but she was concerned our *CoolBot controller* was not NSF certified. Our controller is legally classified as a thermostat and there are no NSF certified thermostats that either of us had ever heard of and of course she was allowed to allow people to have thermostats (and even smart programmable thermostats) installed in kitchen spaces.

She loved the idea of the restaurant saving money, and our break-down rates are so much lower than conventional coolers, so we're way more food safe, PLUS we use much less electricity downstream.

The other case was something silly, the inspector asked for some "proof that we worked" and we pointed them towards the UC Davis/USAID flyer as an independent source of information.

Customers have reported their health inspectors visited them more often in the beginning with spot inspections to see that it was actually holding temperature, but we work great, so it's never a problem!

Obviously the best thing to do is ask your local inspector ahead of time. We have 14,000+ units out there, thousands in commercial kitchens We'd be happy to speak with a local inspector who is concerned or questioning the idea.

ALL THIS BEING SAID: Please read our section entitled Who Should NOT Use a CoolBot.

+What temperature should I store my product at?

Here is a list of common products stored in CoolBots and general sense of their temperature needs.

  • Mixed vegetable and fruit storage: 37-43F. We have a long article on post harvest care for your fruits and veggies We keep our spring and fall crops at 37/38F and summer crops (not including tomatoes) at 41/42F.
  • Flowers: Most people are doing 41F because it's safe for all mixed flowers. Some people want to do in the 30's, which is ideal for some varieties but MIGHT cause cold-damage to more sensitive varieties. Either check your varieties or choose 41F to be safe. The CoolBot can be set to whatever you need.
  • Cheese Cave: 50-55F (depends on the cheese)
  • USDA Inspected Storage for Meat/ Hunter Coolers: Needs to be under 40, we recommend 37/38F so you have a buffer. Some people feel they need to be at 35/36 to have more of a buffer. That is unnecessary and costs a HUGE amount of money in electricity.
  • Wine: 55-57F
  • Beer making/ Keg Storage: Depends! Too much info to include in this short list. The CoolBot can do everything you need to do.
+Will the CoolBot work to keep my wine room cold?

Yes! The CoolBot is a great option for people wanting to keep their wine cold.

50-60F is no problem for the CoolBot. With consistent temperature and humidity we can keep your wine in the perfect conditions.

For more information on wine rooms, check out our page: Wine Room

+Can I use the CoolBot to make my bedroom cooler at night?

Yes and No....

For most of you asking this question, the answer is No -- If you wish your room were 60F (or above) but your air conditioner alone can't get your room that cold, then the CoolBot will not help you at all because it doesn't add BTU's to what your a/c unit can put out. You need a bigger air conditioner NOT a CoolBot.

However, for various reasons, some people need to sleep COLDER than 60F, and in that case, yes, we can help as long as you have enough BTU's to cover it.

Things such as:

  • Gaps Around the Door: If your bedroom door has a big gap under it, that makes a HUGE difference in how cold you can go (cold sinks to the floor and then runs out the door).
  • Gaps Around Windows: Very, very, very small gaps (like 1/4" by 10") can impact how cold you can get the room to be by several degrees (not to mention the difference in electricity consumption).
  • Single Pane or Double Pane Windows? Glass is also a conductor of heat/cold, so people with multiple windows (most bedrooms!) or worse, older single paned windows vs. insulated double glass can't get as cold unless they somehow cover the windows.
  • Top Floor or Bottom Floor? Whether you are on the top floor or the bottom floor can make a difference in your final temperature. Most residential construction has no insulation between the first and second floor and again, cold sinks.

All those things, plus your target temperature effect the total electricity consumption and the size of the air conditioner we would recommend.

As an example, for a modern 10x15 bedroom with good windows on the second floor if you wanted to be in the...

  • Upper 40's: you would need a 24,000 BTU air conditioner. There are MINI-SPLIT air conditioners that are extremely quiet, literally a whisper even as they put out a full 24,000 BTU's. The CoolBot works well with those. Window units are louder, but obviously they work, too and are much cheaper and easier to pop in a window. This size a/c unit requires 220 volts.
  • Low-mid 50's: you could be set with a 15,000-18,000 BTU a/c and making sure to at least throw a towel in front of the door to stop the air from leaking out through the bottom.

If you are on the ground floor and have LESS windows (or are willing to put something over them, like a thin layer of insulation, then you can get away with a much smaller air conditioner (or you can get colder).


+Where I live has very humid weather conditions, can I use a CoolBot?

Yes! The CoolBot/Air Conditioner combination has no trouble running in high humidity conditions -- inside and/or outside the cooler.

We have customers in the bayous of Louisiana, the jungles of S. America, India, equatorial Africa and even down in Papua New Guinea, all running with no problem in 100% humidity outside their coolers.

And we have a number of people who generally want super-high humidity INSIDE their coolers: florists and cheese-makers for example. Still no problem!

+ Does the air conditioner dry out the air? What will be the humidity level in the cooler?

Humidity is going to be the same on both conventional cooling systems and a CoolBot system. You'll probably naturally end up in the 80-90% range, plus or minus that. If it's really packed, you'll be on the higher end, if you're pretty empty, you'll be on the lower end.

If you need more you'll have to use a humidifier, and there is no conflict with running a humidifier and a CoolBot. Simple/cheap vapor humidifiers can even come with humidistats now on Amazon.

If you need lower humidity, you'll have to use a dehumidifier -- which means you'll have to account for the extra heat that the dehumidifier puts out (which just means upsizing the air conditioner a little)

Even in Arizona people end up in that 80-90% humidity level. Outside it might be 25% RH, but when they open the door, and that hot (apparently dry) air cools comes rushing into the room and cools down by 50-60 degrees... that exact same air that OUTSIDE shows up as a RH of 25%, will now measure at 80-90% inside the cooler (colder air can hold much less moisture, so the humidity levels go way up.) Physics is phun.

+I need to keep my product at a higher humidity than 90%, can the CoolBot work in these conditions?

Yes, it will definitely work with higher humidity.

Florists, flower growers and cheese-makers seem especially happy with the CoolBot.

We are often told that the CoolBot allows for more humidity in the air which keeps the flowers better. We're pretty sure this is just an illusion. The flowers are happier, yes, but it's just because you have so much less air blowing around the room with one fan instead of four, so they aren't getting blown on and dried out that way as much.

For florists and cheese-makers that need to keep a lot of humidity in the room, it has been our experience that using a larger than recommended air conditioner is a good idea. The larger air conditioner means the compressor runs less often keeping more humidity in the room.

If you undersize your air conditioner from our recommendations (as lots of people do to save money) it runs more often. You will probably reach your desired temperature BUT the air in your room is CONSTANTLY running over the cold fins and moisture is (constantly) condensing out.

In a correctly sized system the air conditioner compressor is generally running less than 25% of the time (although the circulator fan might be running, but that doesn't cause dehumidification). Bigger systems might be running only 1/6th of the time with very little dehumidification.

+ I am a vegetable and fruit farmer, will the humidity conditions be ok for my produce?

Yes! The CoolBot maintains the perfect RH for veggies and fruits. There is a mis-conception that air conditioners constantly dry out the air, but that's only true to a certain extent. You'll reach a steady state range between 80-90% humidity in produce coolers automatically, Not even 1% of people add any humidity to the produce coolers, and I really wish they wouldn't.

You can, of course, add a vapor humidifier with a humidistat into the cooler. It will NOT effect the function of the CoolBot or air conditioner. But for food safety and also to minimize disease pressure in your produce it's better to think about humidity control on a "micro-climate" level.

Use proper storage containers: for example using mostly closed crates for things that need higher humidity and more open crates for things that want lower humidity. For berries, use clamshell boxes.

You don't have to spend a lot of money to do it: On our farm, we mostly only had open sided/open topped crates, but then we just used plastic to line crates or lay over the top of open topped crates and that worked fine.

+ I am using my CoolBot system for seed storage, will I be able to have the proper humidity levels?

Yes, but you MIGHT need extra dehumidification. We do lots and lots of seed storage facilities all over the world, and they all want to keep the combined humidity and temperature in F under a total value of "100".

To achieve this, there are a few options:

  1. Try different temperature settings. You may find that storing at 42F gives you a steady-state of 50% relative humidity, so that's a total of 92... but if you drop the temperature down to 35F you end up with a relative humidity of 70%. So try different temperatures and see where you end up. Our experience has been the right number for most people (who don't want to use any external dehumidification controls) is going to be somewhere between 40-50F.
  2. Keep the room sealed TIGHT. Make sure all gaps and cracks are caulked or spray foamed to prevent warm air from entering. Make sure the gasket around the door keeps a tight seal. Replace if it is cracked. Warm air carries LOTS of moisture that raises the humidity level in the room once in cools down, even small cracks are constantly bringing in a flood of moisture.
  3. Minimize door entries. If you have a commercial seed storage facility with a lot of traffic, add PVC door flaps to reduce warm air entry.
  4. Use chemical desiccants:

    Sodium Chloride: it's steady state keeps a relative humidity of 72% at best, so that's not actually helpful for seed storage folks.

    Calcium Chloride. This has been the solution for a few people in developing countries where electricity is sketchy. While the quantity effects the amount of humidity that is removed proportionately, the calcium chloride is able to remove twice its weight in moisture and can bring rooms down to 30% and can apparently be dried and re-used.

  5. Use a mechanical dehumidifier. It needs to be one that says it works in basements.
  6. In a very small cooler (that I think was leaky) someone told us they used a couple lightbulbs to add heat to the room which made the air conditioner work a bit harder which pulled more humidity out of the room... I think it's more likely that they sealed the cooler up better at the same time they added the lightbulbs, but... still the principle does seem sound....
+I butcher animals/ am making a Hunting Cooler: will the CoolBot maintain the right humidity for me?

Yes! You don't need to plan on adding either a humidifier or dehumidifier. Some folks have a concern that the air conditioner will dry out the meat too much, but it's not true, the humidity in the room ends up at a "steady state" that's around 75-85% relative humidity that's great for meat, even doing sausage curing.

That being said: We have a FEW people (literally just a small handful out of thousands) that want more or less humidity.

To ADD humidity:

Use a vapor humidifier with a humidistat (you can buy them on amazon, they are not expensive). You can also buy "in-line" humidistats. I don't think a single meat processing person has had to do this (some veggie people have.)

To REDUCE Humidity:

  1. Check for gaps and cracks where air might be coming in from the outside -- warmer outside air carries more moisture and that moisture condenses on cold surfaces (like your meat and the walls). If you have a lot of condensation, then look for gaps and cracks, especially around the doors --replace leaky gaskets. It also saves electricity.
  2. Reduce the number of door openings. Same principle as above: the more fresh air that comes in, the more humidity comes with it. *In busy commercial meat processing coolers where reducing traffic in and out of the cooler is not possible, install PVC strip curtains to reduce the amount of air transfer.
  3. You can use a mechanical dehumidifier, make sure to buy one that is rated for "basement use". These are available on Amazon as well.
  4. You can use Chemical Desiccants. Simple Rock salt will pull humidity down to about 70%, Calcium Chloride (depending on the amount you use) can actually pull humidity down to around 30%! Both can be dried and re-used apparently. These are more solutions for people doing seed storage, I'm not aware of any meat processors that have every done this.
  5. In a very small cooler (that I think was leaky) someone told us they used a couple lightbulbs to add heat to the room which made the air conditioner work a bit harder which pulled more humidity out of the room... I think it's more likely that they sealed the cooler up better at the same time they added the lightbulbs, but... still the principle does seem sound....

For more information on coolers for meat, check out our page


Cooler Construction

+ What if I have a walk in that has no outside walls? Could I set a room a/c in the ceiling vertically and have it blow down?

Unfortunately... no... you can't mount a/c unit's in a side-ways orientation on the ceiling, you'd have to build a sort of alcove on top... and that doesn't seem worth the trouble. You COULD use a "split a/c unit" but they are much more expensive than standard window a/c units and most require professional installation, so... it would seem like it makes more sense to stick with what you have.

Another (seeming) option is one of the "portable a/c" units which use something that looks like a drier hose to vent the hot air out. We've had several people try these and they do NOT work, so don't waste your time.

We've had some warehouses (and more than a few restaurants) mount the a/c units so they are blowing into the restaurant. This is great when it's cold out, but the extra heat that you throw into the place during the summer isn't so great! You have to double the size of the a/c cooling the room - so it's not just uncomfortable it's not a good decision from the perspective of "responsible energy use".

+Can I put a drain in my cooler?

There is a physics principle that is named after someone with a weird sounding name that basically boils down to air moving through ANY hole (like a drain!) exponentially faster as the temperature differential between one side and the other of the pipe increases. The end result is, depressingly, you can warm a cooler up by 5 degrees with just 3 square inches of hole, so if you MUST have a drain, make sure you have an air tight seal for it, and keep it as small as possible. There's not enough water in a cooler to even keep the little s trap filled.

Most people do not need drains, and if there is detritus on the cooler it can quickly clog the drain.

There are drips of water that condense on the ceiling and walls of the cooler. This is because warm air from outside condenses on the cold inner walls when you open the door, but this isn't a huge amount of water... never enough to even use a mop, much less enough to spill into a drain.

We used to take the hose into our farm coolers to spritz all the veggies but we now know this is not recommended because of food safety concerns. Even then it just made the floor wet, it wasn't enough to warrant a drain.

The only people maybe needing drains are folks who do meat processing and regularly spray down the cooler. Otherwise... It's more trouble than it's worth.

The Bottom Line:

There isn't enough water accumulating to necessitate it and putting one in would just compromise the integrity of the cooler. The only thing the drain will really be letting leak out is cold air.

+Could I cool two rooms with 1 a/c by putting a partition in the middle and having one room be cooler than the other?

This is a common question from the veg-farming community. People start with one CoolBot cooler, then they love it but they wish they could have two spaces at two different temperatures (broccoli, kale, lettuce, etc likes to be really cold... but things like peppers, eggplants, squash, cukes, basil gets damaged at those temperatures (or worse, the damage show up 24 hours after you pull them out from really cold coolers). You can pick a compromise temperature (42F is actually what we ship the CoolBots out at) and that works reasonably well, but depending on your total sales, you can see a 1 year payback on costs by adding a cooler maintained at a higher temperature. We'll try to do an entirely different article on payback periods on a second cooler at a future date.

For now, the question is, can you maintain separate temperatures with ONE air conditioner in two rooms, just with a partition.

Short answer: Some have tried... no one is thrilled. Keep your expectations low and it sort of works.

Here's what we've learned:

  1. Temperatures want to equalize, so if you try it just with plastic cooler flaps, you can't maintain very much of a temperature differential between the two rooms over night when no one is opening the door. The back "colder" room that you set at 36 and the front "warmer" room that you wanted to be at 46 will both end up around 41F (maybe it will be 40 in the back, and 42 in the front). Not so impressive. During the day, though, the back DEFINITELY stays cooler than the front if you have a lot of door openings.
  2. To make it better: you can use a solid door between the coolers. You can experiment with gap size under the door to get spillage from one room to the next. Going up by 1/4 of an inch at a time is as much as you would want to play with. You won't get perfect control at in the warmer room without the air conditioner. Your temperature up front will depend a lot on the AMBIENT temperature and how often you close the door (since there is no active control... just the gap under the door). Still it's better than just with flaps between the rooms!
  3. Start with the same solid door idea, but with a very small gap underneath it... add a separate tiny 4" power duct on a thermostat between the two rooms. The downside here is that you will have better control at maintaining the warmer "spill over" room, but... since you are stealing cold air from the original room, on very hot days, or days when you are doing a lot of loading, you will probably see the a/c struggling a bit to keep your first room cold enough. You need to carefully size the BACK air conditioner to account for both rooms.

Bottom line:

For the trouble it takes to do this well, it's not a great idea.We recommend having two coolers with two separate air conditioners.

Having two coolers with 2 separate air conditioners also offers safety-in-reduncancy.

We have over 14,000 units running now, and the number of failures in the 8 years that we've been doing this is VERY small, however that doesn't matter if you are one of the statistical few that has a problem. Having a second cooler you can use as a back-up in an emergency feels AWESOME if something bad ever happens (and if you are looking at setting things to run over decades, it's just a matter of time before something bad does happen). If you maintain a couple thousand dollars worth of produce in the cooler, having that backup pays off IMMEDIATELY.

If you have the coolers at two different sizes, it's also helpful in terms of energy savings to use the smaller one when you can get away with it vs. just the larger one, or both.

+ Can I use one CoolBot for two A/Cs?

A single CoolBot can't control 2 air conditioners, even if they are RIGHT next to each other, they freeze up at different rates so we actually need two "brains" to respond differently, so it is best to have one CoolBot per air conditioner.

+ Can I build my cooler in my basement? Is it okay to vent a window air conditioner into a basement? Can I vent into a storage room?

Yes as long as you have some ventilation into the space.

We have a lot of basement cooler people now -- many of the people who do home wine cellars put them in their basements. That's super easy. Restaurants doing secondary coolers (that don't get opened as much) and keg coolers in bars are all common examples of commercial basement coolers.

A few concerns about venting into an interior room...

  • Heat Buildup. This depends on how often you open the door *and* how cold you want the cooler to be. For wine cellar folks, it's not even noticeable. Wine cellar folks can get away with a cooler in a basement with no ventilation and not even notice most times. Even for restaurant folks it's surprisingly little. You should have two windows "a couple inches more than cracked open" for cross ventilation and you'll be fine even in the summer if it's a secondary cooler at 38F or above. Colder than that or more opening -- then still a couple windows is fine, but in the heat of summer, open them up more.
  • For folks that have just a single window it will be warmer, but it's still not horrible. I visited someone's cooler where the backside was venting into a storage room that was 8x14 with just a single opening and while I didn't like the noise of the air conditioner on my head (we were in there for a long time) it never actually got very hot --hotter than outside, but not bad at all (but he said he didn't open the door even one time per hour.)

  • Water dripping out the back of the air conditioner. For most people this is irrelevant. Put a bucket underneath just in case, but probably you will never have to empty it. Or maybe once a month if you live in a humid area. The water that drips out the back comes from the more moisture-laden air that comes in every time you open the door. It condenses on the fins, then is channeled to the back, and if ENOUGH water is collected it will drip out the back (otherwise it just evaporates).
  • In a residential air conditioner, you get a LOT of condensate drip-drip-dripping out the backside because people are constantly coming in and out, and doors are rarely closed. But in an air conditioner used in a cooler, it's small and sealed up so you get very little water condensing -- it evaporates before it can drip out. Even a restaurant in Georgia that was worried about it wrote recently to say that he only has to empty it ever couple weeks even in summer. (It's a secondary cooler in his basement, not the primary)

  • Gas fumes out the back of air conditioners. There are NO fumes whatsoever on the back of the air conditioner. It's a completely sealed system, so all that is produced is heat. You will feel some air, but it's just from the fan that is blowing air over the warm fins.

Although we have people that have the backside of the air conditioner into a sealed space with NO windows, I don't think that's a good idea. I'm writing so positively about how little water and heat is produced, and that's true, but "very little" is not the same as "nothing". You should be able to open up at least one window, or have a door that's getting periodically opened to vent the heat out unless you are wine-cellar user.

Also, think about the noise the back side of the air conditioner makes. I wouldn't want it in my living space.

Note: For people in garages with no windows, an easy option could be to add a couple VENTS instead of a window. Search on the internet for something 18 in. x 24 in. rectangle gable vent.

+How important is it to have a floor in our cooler?

Please see our section on what works and doesn't work. Floors are important for people cooling below 45 degrees because cold sinks and the ground always stays warm. By skipping the floor you've created an endlessly hungry "cold sink" that is sucking money out of your pocket in the form of electricity. The CoolBot will WORK without a floor, but it's going to cost you. Below 40 degrees if you are going to skip the floor you should size up a level on the a/c unit. For hunters only running the CoolBots in the fall... it's not going to pay to put in a floor because you don't run that many months of the year, but everyone else should (below 40.)

For people installing CoolBots on trailers you MUST have a 4" thick insulated floor or the CoolBot will never be able to keep up with the cold you are dumping down the highway.

Standard insulation is 4" thick styrofoam on walls, floor and ceiling.

Just as important as the floor is that you use tape, caulk or spray foam to seal up every edge and corner in your cooler. Even a 1/4"x2" hole dumps an ENORMOUS amount of cold (and your electricity $) into the environment.

+My wall is super thick, can I still use a window unit?

Yes! Our walls were 11 inches thick and we used a window unit no problem. If your wall is more thick than your a/c is long you have some options:

  1. Mini-Split: Doesn't matter how thick your wall is. It's just a 3 inch hole to pass a couple tubes through. The evaporator hangs on the inner wall, and the compressor sits on a plastic or concrete pad outside (or hangs on the wall... or you can put it on a flat roof). They are super quiet. Everyone in Europe uses them. We think they are great, but they are a bit expensive here. Search for mini-splits we work with all brands except Panasonic is TOO annoying to bother with, and FUJITSU... while it is a terrific brand, makes it's really hard to access one of their sensors, but every other choice out there is really easy and quick to set up.
  2. "Thru-wall" air conditioner. Bad choice, they are more expensive and for some inexplicable reason they break down more than window units by the exact same manufacturer. Often times, you have to special order them. But these definitely work if you don't care about money or reliability :-)
  3. Standard window unit, but make your hole WIDER by 4-9 inches on either side of the air conditioner, and then put the air conditioner in the center of it.

Get the air conditioner first so you can see for yourself (and in case something is different on your unit) but NORMALLY:

Let's say the air conditioner is 15 inches high and 20 inches wide. There are vent holes on the left and right back side of the air conditioner. So you'd cut a hole in your wall that is 15 inches tall by 28"-38" wide. The air conditioner is basically "inset" into the wall but air can still get to the vent holes! Simple!

It's a good idea to go bigger than the air conditioner anyway (vertically and horizontally) in case you ever want to change and the next model is bigger.

The bigger the unit, the more surface area for cold transfer so the slower you can run the fan so the more EFFICIENT the unit will be.

+ My room is 20x20... can I still use a CoolBot?

Yes. But you have to install multiple CoolBots. Our biggest installation so far is 60x40 with high ceilings. It's a watermelon farm so they are doing a lot more mass than most people (but they don't need to get it as cold). We saved the guy tens of thousands of dollars.

Someone also did a 40x40 installation for meat storage for the "Boar's Head" brand saving over $25,000 in installation costs alone (not to mention ongoing electricity savings).

20x20 installations are very common for us and require the purchase of two or three CoolBots and 2-3 a/c units (depending on temperature and use and tons of product coming in if it needs to be cooled). We're still much cheaper AND then you can program some of the units to only kick on at peak loading. There is also safety in redundancy - multiple units means that even if one unit goes down you still have others running so you don't lose everything! STATISTICALLY speaking we are tracking very low failure rates, but that's not much comfort if you are one of the people that has a problem.

+ How do I build by cooler into a pre-existing room in my house?

The best and easiest would be to probably just leave the drywall and then add rigid foam insulation on top. The idea is that with rigid foam insulation, there won't be a cold backside so condensation won't gather.

If there was already insulation (fiberglass batt) inside the existing walls that you were building against, we could put 2-3 inches of rigid foam on them. That would be enough to bump us up to an R value of 24 and prevent moisture damage from occurring in the drywall and batt insulation.

Be sure to seal the insulation tight. Use caulk and spray foam on every gap, crack, or seam to prevent air from leaking through..

+ Can I build a duct system for the heat exhaust? For the cold air?

We highly recommend against building any sort of duct work around the system.

On the backside, where the heat is exhausted, we need to have that area free and clear so the a/c can "breathe". If there is any sort of obstruction, it will cause the compressor to overheat and eventually die a premature death. Allow a 2 foot radius around the unit to be clear and be sure it is in a place where the heat can be ventilated. If it is indoors, make sure there is a window or door that is open.

On the cold side, we have had many people try and it really just doesn't work. Often times the cold air bounces back into the fins causing our fin sensor to be tripped and shut off the compressor early, or it could cause ice ups. Even the neatest, cleanest, most professional jobs have not had satisfactory results.

Avoid boxing the a/c system in on either side for the best results.