February 10, 2017


Bumper Crop: C02 in the Garden

Nothing makes the indoor gardener happier than a large, healthy crop—beautiful green leaves, healthy and colorful fruits and vegetables, heavy and aromatic flowers.  But no matter what you are growing, the limiting factors to crop health and overall production are the same:  nutrient, climate, lighting, pest control.  Every plant has different requirements for optimum health, but these four factors can make or break a harvest in any gardening scenario.

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Creative Control: Out of the Box Cooling Solutions for the Summer Garden

Summer brings with it so many wonderful things. Lake and beach time, fireworks and barbecue, sun and…heat. Summer can present quite a challenge for most indoor gardens, as the skyrocketing outdoor temperatures affect the temperature in the garden significantly. 

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Water Culture Systems in the Greenhouse

One of the joys of greenhouse gardening is the options it provides us in how we choose to garden.  They types and numbers of plants that will thrive in a greenhouse environment are nearly endless, as are the gardening methods we can use.

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In Control: A guide to achieving the perfect climate

As every gardener knows, hydroponic and indoor farming can present a number of challenges.  Cycle after cycle, it seems that there are always obstacles that have to be overcome.  Every harvest, we challenge ourselves to do better next time.  Regardless of the hurdles, we keep at it, and eventually we usually get it right.

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Total Control: Choosing the Right Cooling System

So you've decided to build a new garden.  Oh, the choices you have to make!  What kind of reflectors, bulbs, ballasts?  How many plants will fit in the space?  Do you want to use a hydroponic system or traditional dirt methods?

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Hydro Innovations, Expert in Heat Control

Hydro Innovations is a young, dynamic company started and owned by an experienced indoor gardener. As our name implies, we believe that there are a lot of "thinking out of the box" innovations that can be made to improve indoor gardening, primarily in the area of heat control, which is...

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Can water absorb heat better than most substances?

Water is a one-of-a-kind substance for many reasons. An obvious one is its unique ability to absorb heat. Water is able to absorb heat - without increasing much in temperature - better than many substances This is because for water to increase in temperature, water molecules must be made to move faster within the water; this requires...

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Grow All Summer: Water-Cooling Explained

A water-cooled system is a complete cooling package that can have several components. It generally consists of water lines connected from a chilled reservoir or fresh water source to various heat exchangers, water-cooled lighting vessels, ballast cooling enclosures and/or CO2 generators...

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Chillout : Water Chillers Explained

Let`s start with chiller basics - what is a water chiller and why would a person want one? A water chiller does just what its name implies - it cools water. Chillers are used in indoor gardening for a wide range of applications including nutrient cooling and watercooled equipment such as CO2 generators, dehumidifiers, air conditioning...

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Design: WC Room

This is an 8 light system that can be used with any size bulb. Water is pumped from the reservoir and pressurizes the supply manifold which pushes water through the Ice Box heat exchangers and any other water-cooled equipment that you are using. Air is passed over the Ice Boxes which warms the water before returning back to the reservoir via...

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Circuit: Water Chiller Refrigerant Circuit

Water Chiller Refrigerant Circuit.

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Cooling Towers and Dry Coolers

With the launch of the Surna Reflector, there will be a few new terms popping up around here. These include Cooling Towers and Dry Coolers. Due to the high-heat of the bulb, the Surna Reflector can be effectively cooled using Cooling Towers and Dry Coolers during most of the year in most regions.


Let’s start with a quick explanation of how refrigeration typically works. Typically, refrigerant flows through a compressor, which raises the pressure and temperature of the refrigerant in vapor form.  The refrigerant vapor then cools and condenses into a liquid. Then the liquid refrigerant is allowed to expand and this expansion drops the temperature below its starting temperature. Remember, the process of cooling actually involves removing heat, not adding cool. This process is called the vapor-compression refrigeration cycle. To learn more read this article.

However, with Cooling Towers and Dry Coolers, a compressor is not necessary to reject heat. Instead, fans are used to move air over a heat exchanger, creating a more efficient means of providing cooling.

Cooling Towers

Cooling Towers use evaporation to provide cooling. But don’t worry, the cooling tower is located outside and will not add extra humidity to your grow room. Cooling Towers are commonly used to cool nuclear power plants, so you know they are capable of processing large amounts of heat.

In a Cooling Tower, hot water is sprayed on a medium in order to spread it out. From there, outside air, which is cooler than the water, mixes with the water and causes evaporation. For a better explanation, watch this video

Because of the evaporation, Cooling Towers require continuous water refills to maintain an appropriate water level.

Dry Coolers

The main difference between Dry Coolers and Cooling Towers is that Dry Coolers do not require water. Instead, air is blown over a heat exchanger in order to remove the heat from the liquid in the system.

Dry Bulb vs Wet Bulb

In order for Cooling Towers and Dry Coolers to work, the temperature of the water in the system needs to be hotter than the air temperature. However, air temperature has two parts: Dry Bulb temperature and Wet Bulb temperature.

Dry Bulb temperature is the temperature thermometers read. This is the temperature referred to when talking about how hot it is outside.

Wet Bulb temperature, on the other hand, is the temperature a thermometer would read if it was wet and had air moving over it. Wet Bulb temperature is affected by the humidity in the air and will always be lower than the Dry Bulb temperature.

Cooling Towers work as long as the Wet Bulb temperature is lower than the temperature of the liquid running through it. When talking about cooling a Surna Reflector, the water to be cooled clocks in around 120 degrees F. So the wet-bulb temperature only needs to be around 85 degrees F (or lower) in order to work properly – a condition that is achievable in most of the country throughout the year.

Dry Coolers work off the Dry Bulb temperature, meaning the outdoor temperature needs to be lower than what Cooling Towers require for effective heat transfer. As such, Dry Coolers are not as effective year-round as Cooling Towers.

However, Dry Coolers are easier to maintain because the water is not exposed to air (closed loop) and they do not require water testing . Cooling Towers are susceptible to degradation through fouling (getting clogged up), scaling (water-deposit build-ups) corrosion (gradual breakdown due to the environment), and require testing for the prevention of Legionnaire’s disease.

Overall, depending on the climate in which you live, Dry Coolers and Cooling Towers can provide an efficient way to cool your garden, especially in combination with Surna Reflectors.

Brandy Keen
Brandy Keen


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