Market need

In South Africa’s climate of temperature extremes, cooling of mobile network Base Transceiver Station (BTS) equipment shelters can present a significant challenge.

Traditionally, suppliers have focused on throwing quantity at the problem, simply advising clients to procure more air-conditioning as part of an inefficient solution matrix involving ever more power consumption backed up with generators and uninterruptible power supplies.

But faced with tightening budget constraints, attaining optimal power efficiencies while keeping internal environments within strict electronic equipment operating temperatures must be at the top of the hierarchy of cooling needs.

Presented with this complex set of requirements, Tellumat’s infrastructure solutions team set about looking for a cooling solution operating at the optimal intersect between effectiveness and efficiency.

Technology solution

The Tellumat TK1 Positive Pressure System AHU (air handling unit) is a free air-cooling system specifically designed for cooling the equipment shelters of cellular base station sites operating at increased heat loads and in high average ambient air temperatures. The system is similar to traditional free air-cooling systems, but offers some unique improvements.

– To maximise the use of free cooling, the TK1 monitors ambient air conditions inside and outside the base station shelter and controls the cooling mechanisms (air-conditioners and free air cooling) in order to optimise energy consumption.

– In addition, it controls the airflow path through the shelter – expelling hot air directly from the top of the main heat source using filtered air so not to contaminate the equipment shelter.

Main features

The system consists of the following components:
2. Free-cooling supply box (with air filters).
3. Heat source exhaust relief/outlet.
4. Supply flow grille and heat source cowling for mounting the TK1 on the shelter.
5. Positive Pressure controller (with air-conditioner switches).


There are many possible installation configurations that enable the TK1 to be retro-fitted onto existing equipment shelters with one or more heat sources. It is also suitable for new site builds.


The TK1’s optimal design allows efficiencies of power utilisation while ensuring that the equipment can operate effectively under high operating loads. The result being significantly lower electrical power consumption and therefore a lower cost of operation of the BTS for the mobile network operator.

The monitoring of temperatures and air flow regulation allows the system to keep the internal ambient temperature of the equipment shelter extremely close to the equipment’s specified operating temperature range while using low power free air-cooling, as opposed to running high power consumption air-conditioning systems for extended periods. As a result, mobile network operators can negate the need to have their BTS air-conditioning on around the clock, thereby accruing massive cost savings, a far more positive carbon footprint, and more optimal use of energy.