Standard water baths often have a temperature range from ambient +5°C to somewhere between 80 and 100°C. While this range is satisfactory to most users it doesn't allow for a water bath at near ambient temperatures. To maintain your water bath at near ambient temperatures you will need a setup that is capable of both heating and cooling. Water baths such as the JULABO or PolyScience refrigerated and heating circulating baths can do both but are quite expensive. Instead you can combine units that are capable of heating or cooling. The combination of PolyScience's 13 L Refrigerated Open Tank Bath with an LX Immersion Circulator is the least expensive option to create a near-ambient (or even refrigerated) open tank bath.
PolyScience 13 L Refrigerated Open Tank Bath and LX Immersion Circulator.