Water Chillers and Heaters
Whenever we’re talking about water chillers and heaters it is essentially the same thing. This is all about maintaining an optimum root zone temperature to improve the health and vitality of our grow. Most often than not, this involves chilling but there are cases and environments where heating may be necessary.
A newcomer may be wondering why chilling and heating is even needed anyhow. A water chiller or heater is one of the most vital methods of maintaining optimal root zone temperature. Hydroponic gardens benefit greatly from the oxygen-rich solution temperatures that water chillers and heaters provide.
The optimum root zone temperature is 65-70◦ F.
This temperature range raises dissolved oxygen levels and will boost your plant’s immune response to diseases. When the nutrient solution is too warm dissolved oxygen levels are considerably lowered. This combined with the lower oxygen creates the optimal growing conditions for harmful pathogens.
Lower dissolved oxygen also reduces usable oxygen to the root zone which will result with weak or stunted plants.
Choosing exactly the correct unit
Today’s water chillers and heaters are far more effective and efficient than those of 20 years ago. Chillers and heaters today are not just the glorified, expensive versions of aquarium chillers that they used to be.
The chillers and heaters today are specifically designed for hydroponic gardening and types are better tailored to individual needs. This is really important for the grower who needs to carefully select the right chilling/heater unit better fit for your garden and your conditions.
The grower in Florida has much different performance expectations than the one in Minnesota and this needs to be foremost in your mind when purchasing a chiller or heater. A water heater to the grower in the south isn’t much of a priority but it’s a major issue for the one in the north.
Chillers and heaters work in harmony with the water pumps.
Normally, the very mechanics and friction of pumping and circulating will warm the nutrient solution to a certain extent. When the solution is run through the chiller it runs through coils where the solution is cooled to the set temperature.
The cooled solution is pumped back throughout the entire system at an ideal temperature that will make root stock and your plants, thrive. Likewise, a water heater works on the same principle other than its reversed.
Properly sizing the water chiller or heater required
Thankfully, chilling heating precise and predictable sciences and there is a method that can be followed fairly accurately to properly size a unit to your specific garden.
- Calculate total system volume– reservoir capacity, any bucket system and residual tube solution.
- Run everything in the grow room- this will allow the grow room to max out its temperature.
- Monitor temperature– max out the temperature several times or more and determine the average maximum temperature.
- Cool with ice packs– use ice packs to cool your system as it is running as a temporary method.
After you run the system for an hour, notate the final nutrient solution temperature. Use the formula developed by Kevin Espiritu to determine the specifications-“Total system volume in gallons X 8.34 (the established weight of water) X the starting and ending temperature difference= the minimum BTU per hour needed.”
The BTUs required per hour are the same whether you’re cooling or heating, so this formula works both ways. It is also suggested that a water chiller be purchased that is 20% above the minimum BTUs to compensate for any performance lost during the pumping process.
Additionally, it is strongly recommended that you choose a titanium heat exchanger which prevents minerals from leaching.
Final thought on water chillers and heaters
The area of water chillers and heaters is one that there is at present no set norm in hydroponic gardening. Whether to invest in those on the market is largely left up to the individual grower.
There are those growers who don’t use them at all and others who try DYI methods in which the effectiveness is somewhat in question.
Heating the nutrient solution with a stock tank heater or cooling it down with ice packs may do the job but to what extent? The problem is that these methods are not accurate, and it would seem difficult, if not impossible to maintain a consistent desired temperature using them.
If you’re really in doubt as to whether to use a water chiller or heater the best route is to monitor and record the nutrient solution temperature over the course of time to see where you’re at.
If the solution is staying right within the desirable temperature range than the chances are good that you won’t really need one. But if it is jumping all over the board then don’t take a chance with your crop and invest in one.
Growing, maintaining and harvesting a healthy crop is really the priority and a grower needs to do whatever they can to achieve and improve on that. The relatively low investment in a water chiller or heater is just part of that equation, in our view.