The Maisotsenko Cycle - Basic
A Basic View of the Maisotsenko Cycle
The following basic description of the Maisotsenko Cycle is meant for all readers. A detailed scientific description and a conceptual description are also available on this website for readers who have a deeper understanding of thermodynamics.
Steps to Understanding the Maisotsenko Cycle:
1. Review dry bulb, wet bulb and dew point temperature terms.
2. Learn what a heat exchanger is.
3. Understand how an evaporative or swamp cooler works.
4. Understand the indirect evaporative process.
5. Make the jump to understanding the Maisotsenko Cycle.
Dry Bulb Temperature
The dry bulb temperature is the air temperature measured using a standard
thermometer. It is the temperature reported in daily weather forecasts and is
sometimes referred to as the ambient air temperature.
Wet Bulb Temperature
The wet bulb temperature also uses a standard thermometer; however, a wet piece
of cloth covers the bulb of the thermometer. As air passes over the wet cloth,
the water in the cloth evaporates, drawing heat out of the thermometer.
If the air is very humid (moist), only a small amount of moisture will evaporate
from the cloth. This means the wet bulb temperature will only be a little lower than
the dry bulb temperature.
Conversely, if the humidity of the air is low (dry), the moisture will evaporate
from the cloth quickly. This means that the wet bulb temperature will be much
lower than the dry bulb temperature.
If it is raining or there is heavy fog, the air is saturated, and the dry bulb
temperature will be equal to the wet bulb temperature.
Dew Point Temperature
The dew point temperature is the air temperature where the moisture in the air
begins to condense or change from a vapor to a liquid. In order for a surface
to collect dew out of the air (like a glass of ice water or blade of grass),
the temperature of that surface must be at or below the dew point temperature. The dew
point temperature is always the coldest of the three temperatures.
Heat Exchangers
A heat exchanger is a widely used device that transfers heat from one fluid
(liquid or gas) to another. The fluids do not come into contact with one
another.
A commonly understood heat exchanger is the radiator in a car. In this example,
hot fluid from the engine flows inside tubes in the radiator. Air is passed over
the outside of the tubes and cools the hot fluid without coming into contact
with the fluid.
Other less obvious examples of heat exchangers are refrigerators and air
conditioners. These examples transfer heat when a fluid (refrigerant), changes from a
liquid to a vapor in the evaporator, and then from a vapor to a liquid in a
condenser.
Direct Evaporative Cooling
Evaporative coolers are popular in dry regions of the world. Water runs over an absorbent material like wood fiber, and then outside air is blown
through those fibers. Moisture is added to the air, and the air feels colder.
This process is similar to your body sweating, and being cooled by moisture
(sweat) being evaporated.
In humid regions evaporative coolers do not work well for human comfort cooling because the air is
close to saturated (nearly as moist as
it can be). Consequently, adding moisture will not significantly lower the temperature of the air. Similarly, when your body sweats on hot, humid days, you do
not feel cooler because the moisture on your skin does not evaporate off very
quickly.
Evaporative coolers add
moisture to the air by
blowing air through a
wetted surface.
An evaporative cooler can get to within 70 percent to 95 percent of the outside air’s wet bulb
temperature.
Indirect Evaporative Air Cooling
You don’t hear much about indirect evaporative air coolers because the little
bit of added cooling has not been worth the added cost of manufacturing.
The concept of indirect evaporative air cooling is to cool using the principles of
evaporation in a heat exchanger. The exchanger prevents moisture from being added to the product
air stream (the air that is going into the building).
Cross section sketch
shows an indirect
evaporative cooler.
In theory, the product
air stream should be able to almost reach the wet bulb temperature without
adding any water to the final product output. In practice, however, the effectiveness of
these types of coolers is reported to approach 54 percent of the incoming air wet bulb
temperature. This is largely due to limitations of geometry and manufacturing.
The Maisotsenko Cycle
The Maisotsenko Cycle uses the same wet and dry channels as described in the
above indirect evaporative cooler but with a much different geometry and airflow
creating a new thermodynamic cycle. It works by incrementally cooling and
saturating working air, and benefiting from that cooling on the next increment.
This two-dimensional, simplified diagram of the Maisotsenko Cycle, shows how air is incrementally cooled by the continuous exhaust of heat followed by additional cooling.
This cycle allows any
fluid (gas or
liquid) to be cooled below the wet bulb and within a few degrees of the dew point
temperature of the incoming working air. In addition, no moisture is added to
the product fluid stream.
The tremendous benefits of the Maisotsenko Cycle are being used by people around the world today. Idalex's manufacturing company, Coolerado, is selling coolers worldwide as the Coolerado Cooler.
An independent testing laboratory tested the Coolerado Cooler which uses the
Maisotsenko Cycle. The results show that the product air is up to 22 percent below the
wet bulb temperature, and to within 85 percent of the dew point temperature.
Stop the Presses!
This last paragraph will forever change the way textbooks are now written. The
Coolerado Cooler using the Maisotsenko Cycle has achieved real (NOT theoretical)
temperatures below the wet bulb and approaching the dew point. Some
recently published works deemed this impossible.
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