CoolBots- How most small farms power their walk-in coolers

Storm Cloud Rolling Over the Farm, Summer 2026

Traditional refrigeration (walk-in coolers, upright shop units with doors, home refrigerators, etc.) uses an electromechanical process that includes a compressor, condenser, expansion valve, and evaporator with a working fluid (refrigerant) to move heat out of the insulated box/refrigerator.  Refrigerant is a fluid that has typically relied on hydroflourocarbons to work its magic- these have negative impacts on earth's ozone layer.   Although many advances have been made in this realm- including tighter EPA regulations that have spurred the development of alternatives that have less negative impacts- the installation, operation, and maintenance of these systems are very expensive and oftentimes out of reach for small farms... You know, just about 86% of all farms in the US!

In 1999, farmers in upstate New York (Kate & Ron Khosla- yes, sounds like coleslaw) were looking for an alternative to traditional refrigeration for their farm, since it is so expensive to install and even more expensive to repair.  And let me tell you, as someone who worked in the grocery industry for over a decade, refrigeration is extremely expensive to maintain and repair!   At one of the stores I used to run, we spent $3,500 a month just on our refrigeration contract to handle any basic maintenance and upkeep.  And the units broke down more often than you would imagine, requiring even more $$ for emergency repairs, double time for off-hours work, expensive parts that often had to be ordered, and trip charges for multiple visits to fix one problem (trip charges were usually at minimum $100 per visit).  So in a nutshell, traditional refrigeration is expensive and out of reach for the majority of farmers in the US.   

 Ron Khosla teamed up with a friend from Cornell U. and invented what is known as the CoolBot- a piece of equipment that applies sensors and probes to a regular air conditioner unit, tricking it into running at a much lower temperature which can provide temps from 35-41 degrees.  It was an amazing invention that launched in 2006 and revolutionized the world of refrigeration, making it affordable for many farmers around the world -including us many years later!   As a note, the refrigerants in A/C units have progressed slightly and are not ozone-depletors, but are considered super-polluters as their warming effects on the climate are hundreds to thousands times higher than CO2.   And for the CoolBots- you can't use just any old A/C unit- there are certain brands with specific BTU's to match your walk-in cooler size.  So oftentimes it does require a bit of leg work to hunt these units down.  I remember one time about 5 years ago when ours broke down in the middle of an oppressively humid heat wave and we drove all over trying to secure the exact right match for our needs.   Often, when you find the model you need, it's not the same size as the old one and requires clever carpentry to retrofit it into the space the old unit occupied.   So it can be a huge deal when the unit goes bad!     

Humidity does a number on these units, which are oftentimes working beyond their capacity to deliver safe food holding temperatures.  And honestly when we started farming back in 2014, we had little-to-no issues for quite a few years as weather conditions were much more stable and predictable.     Sure we had heat waves, but not the kind of frequent tropical-like oppressive humidity that has become much more common since 2021.  Adam and I actually call 2021 the tipping point with regards to climate change (but that is a topic for another day).   That was the year it got extremely humid in mid to late June, and didn't quit until almost August.  That July it rained for 3 weeks straight, delivering almost 28" of rain to our farm and flooding out farms all across CT (not ours, as our soil-health practices were delivering better infiltration rates that made us more resilient).  That was the year that rain forecasts started to look like snow forecasts ...in the inches.  We lost an entire grove of quince trees in 2021 that succumbed to bacterial issues spawned by humid conditions (some of you might remember the Membrillo Quince Paste we used to make and sell).  And even though we weren't under water, wet humid conditions certainly impacted many crops leading to many losses for us and so many others.

So, although the CoolBot revolutionized the world of refrigeration for farms all over the world, current shifts in the climate and frequent patterns of super humid conditions really impact ours and many other's ability to operate our walk-in coolers.   We are still working on an issue caused by the humid conditions of early August to one of our walk-in coolers, but luckily we have only had a few brief super-humid periods lately which has clarified what the problem is and what we need to do to fix it.  Yes, we have 2 walk-in coolers because our original cooler we built 12 years ago just isn't large enough to support the increased appetite you all have for Unbound Glory veggies!!!