The GOHL-HEGER product line features the following:


Cooling Tower Types


The DT cooling tower is used where chillers require large quantities of water. In industry the cooling water from air compressors, diesel engines and generators can be re-cooled and recirculated. The use of a cooling towers for re-cooling water is based on the high evaporation temperature of water. By using a heat ex-changer, up to 98% of water can be saved.

The application of a cooling tower for water re-cooling is based on the high vaporization (latent) heat of water. Through the application of a re-cooling unit some appreciable water saving of up to 98% can be achieved. Space-saving design, easy assembly easy maintenance and operations plus an extensive array of accessories make the DT cooling tower an unbeatable choice. DT Cooling Tower01sf Requirements:
  • no high demand on the quality of the cooling water
  • initial costs more important than maintenance costs
  • low cooling water temperatures (approx. 5K above wet-bulb temperature)
Areas of use:
  • in the open
  • on top floors
  • in rooms with high ceilingsGohl Heger Highly Efficient Cooling red 001
Your benefit:
  • uncomplicated system / easy maintenance
  • small dimensions / space-saving design
  • low noise level
  • low weight
  • low consumption of electricity
  • low investment costs
  • simple installation
  • extensive range of accessories


With the Cooling Tower DT XL GOHL-HEGER has designed a Tower with a higher cooling capacity (15% more) with the same floor space requirements.this is great when there is limited space to place the coolers.


The side-stream cooling tower is used where large amounts of water are required for refrigeration machines (same as vapor tower), but where the installation conditions, for reasons of space, only allow a lateral connection of the air duct system, i.e. in the mezzanine, basement or rooms with low ceilings. Horizontal ducting, exhaust air deflectors are integrated in the device - no incidence of debris entering the cooler from above

Cooling tower with closed circuit–type VK–Evaporative Cooler

The water that needs to be cooled flows via an inlet into a heat-exchanger coil system (primary circuit). The water for cooling, is wetting the heat-exchanger coil system, evaporates and cools the coils (secondary circuit).

In situations where clean, non-deposit forming or corrosive fluid is required for your cooling needs, Closed Circuit Coolers provide optimal performance.

The VK Evaporative Cooler comes in a comparative compact design.

The units can be installed outdoors without requiring a large installation area. With the appropriate precautions (antifreeze), year-round operations are no problem.


  • used if there are high requirements to the cooling medium
  • no corrosion in the closed primary circuit
  • very low water outlet temperatures reachable through evaporation
  • hybrid / dry-cooling operation possible
  • low complexity and very solid system performance
  • low noise level because of closed construction
  • low energy consumption
  • very economic and efficient way to cool
  • water quality in accordance with VDI 3803 without limitation applicable
  • easy accessibility for maintenance due to design of the units
  • outside or inside installation of the units (inside installation of the units with corresponding ducts possible)
  • additional reduction of noise level possible (silencers)
  • winter-operation also possible without antifreeze (glycol)
VK Closed Cirquit Cooling Tower Schematic01SF
Axial Evap Tower01sf


The axial cooling tower VAP is applied where large amounts of water are required for refrigeration machines and / or low cooling water temperatures need to be reached. There are no high standards for water quality. In the Industry the cooling water of air compressors, diesel engines and generators, e.g. rolling stock, lubricating oils and cooling emulsions, etc. can be re-cooled and reused the application of a VAP cooling tower for water re-cooling is based on the high evaporation (latent) heat of water. Through the application of a re-cooling unit some appreciable water saving of up to 98% can be achieved. Efficiency, simple assembly, corrosion resistance and the extremely lightweight design make the VAP the ideal cooler for
  • high re-cooling performance
  • limited installation spaces
  • limited roof loads (static of buildings)


  • Very small installation surface
  • Very low water outlet temperatures Smallest weight of all re-coolers with equal cooling capacity
  • Easy maintenance
  • Easy accessibility for maintenance, large access area
  • can be completely disassembled for cleaning
  • Direct drive motors (better efficiency and no more V-belts or gearboxes)
  • Least expensive and most efficient kind of re-cooling
  • Uncomplicated and robust system
  • Very low acquisition cost
  • Low electric power consumption
  • Water quality according to VDI 3803 applicable without limitations
  • Sound reduction possible by use or silencers
3 different models from 900 KW to 2050 KW are available
Hybrid cooler04

Hybrid Cooler with several patents registered by GOHL-HEGER

The HYBRID Cooler is a WET & DRY Cooler combination. It combines the advantages of the Wet & Dry Cooler without the disadvantages of both and makes one great product for cooling.

A HYBRID Cooler works at:
  • high temperatures as an evaporative cooler
  • medium temperatures as an evaporative & convection cooler
  • low temperatures as a pure convection cooler
The wetting / humidifying of the heat-exchanger can in effect bring the temperature below that of the surrounding air. This is due to the evaporation of the water on the surface of the heat-exchanger.
This makes it possible to cool the medium below the surrounding air temperature which in turn helps with the investment cost/benefit calculations.


The HYBRID Cooler HK is a patented Process developed by GOHL-HEGER
WET & DRY Cooler combinations are environmentally friendly due to the fact that they save up to 75% water compared with evaporative cooling alone. The process is controlled only by the cooling need of the medium.
The HYBRID Cooler has more demand on cooling water quality.

The advantage is a lower cooling medium temperature and:

  • No Legionella risk
  • No Water in the basin
  • Low operating cost
  • Low water consumption
  • Modern, environmentally friendly refrigeration system
  • Closed cooling tower
  • Low cooling water temperature
  • Small (fresh) water demand
  • No deposits or corrosion in the cooling circuit
  • Low maintenance
  • Highly winter safe
  • No plume formation


  • No water treatment required

  • No chemicals needed

  • No water spray in airflowTopaz Cooler01

  • Elimination of Legionella Risk - no bacteriological growth !

  • Very low water consumption (savings to 70 %)

  • Permanent magnet motors (efficiency better IE3)

  • Low operating costs

  • Easy maintenance due to vertical H shape of the tube coils

  • full access through a central door

Our TOPAZ Adiabatic Cooler is a combination of a dry cooler with an adiabatic pre-cooling section.
This pre-cooling section lowers the ambient air temperature by evaporating water.
The water is passed over cooling / humidifying pads, specially designed for this purpose.
The fluid is cooled in the dry tube coil by ambient air flow.
The ambient air is drawn through the coils by fans mounted centrally on top of the Cooler Unit; the humidifying pads located in front of the coils are dry when wet bulb temperature is below 23 deg C (73.4 deg F).
The Wet/Dry set point is around 23 deg C (73.4 deg F) in continental climate for a fluid outlet temperature of 27 deg C (80.6 deg F)
This saves a lot of water from day to night and all the days when the temperature is below 23 deg C (73.4 deg F)
The fan speed is controlled by VFD depending on heat load to maintain the fluid outlet temperature.
The warm air is evacuated upwards.
When cooling in dry mode is not effective and the ambient temperature reaches a predetermined set point, the pads are saturated with water from the sump.
The ambient air is cooled by evaporation while passing through the pads. This pre-cooled air then passes through the tube coils and cools the fluid.
The water which has not been evaporated on the pads is collected in a stainless steel collection sump.
The collected water is re-circulated in the process and distributed over the pads again.
The water savings are significant and no water treatment is required.
No chemicals needed !
There is no bacteriological risk associated with this cooler (no Legionella etc.)
Winter Operation
The primary cycle is filled with a 35% Ethylene Glycol mixture with a freezing point of -21.8 deg C (-7.24 deg F).
At temperatures lower +12 deg C (53.6 deg F) the humidification system is emptied and the replenishment valve closes automatically.
The TOPAZ range is robust due to its design and choice of materials, and specially developed for both industrial and urban environments.
TRENDS in WATER RATE INCREASES 1993 - 2007 based on US Region

TOPAZ Advantage

  • No water treatment required
  • No water spray in airflow
  • Elimination of Legionella risk
  • No dirt deposition in heatexchanger
  • Eurovent certified tube coils
  • Very low water consumption
  • Permanent magnet motors (efficiency better ie3)
  • Low operating costs
  • Easy maintenance due to vertical H shape of the tube coils
  • Full access through the central door

Our TOPAZ Coolers can help you buck the trend... (Cost & Benefit)


The pre-cooling circuit is activated when the fluid outlet temperature is higher than the set point. This wet / dry set point is around 23 °C (73.4 °F) in a continental climate, for a fluid outlet temperature of 27 °C (80.6 °F)


go to our Cost & Benefit page to see the savings

Cost & Benefit has to be calculated over the course of a year (and the life cycle of the tower) and is a simple comparison of:

  • Water Consumption m3 (ft3)
  • Power Consumption KW (Hp)
  • Water Treatment Expenses (chemicals, maintenance etc)
with this in mind we need to compare the different cooling options (open, closed, hybrid, adiabatic) to come up with a comparison between the systems based on: (follow us down the page to explore...)

Cost Benefit – different Cooling Tower designs to Topaz Cooler

If the past is any lesson, the rates will probably increase 3 – 6% annually…that also means that water / energy cost can double or quadruple within the life time of our towers… (15-20 plus years)

The one open factor in all of this is the raise of Water and Energy costs.

Water rate Increases 1993 - 2007 US region

GOHL-HEGER Evaporative Cooling Towers01 455 x 350