Utah State University, USA
The most expensive component of a growth chamber is the cooling system. When the compressor fails, replacement can cost $2,000 to $3,000. The age of a growth chamber or the availability of funding may make replacement of the compressor impractical. Such a growth chamber is the ideal candidate for conversion to water-cooling. While the chamber will not be capable of cooling to near freezing temperatures, a fully functional chamber can be up and running for a few hundred dollars, and it will serve fully 90% of experiments commonly done in growth chambers.
Hay, Alec and Bugbee, Bruce, "Cooling with Water: An Economical Alternative for Plant Growth Chambers" (2008). Controlled Environments. Paper 8.