Do All Telecom Enclosures Require Enclosure Air Conditioners?


Do All Telecom Enclosures Require Enclosure Air Conditioners?

The almost insatiable demand for high-speed internet has led to a situation where the number of telecom enclosures needed to meet these requirements is growing almost exponentially.

Although modern telecom equipment is robust, the power requirements of high-speed data communication equipment are such that the power density inside telecom enclosures is increasing at a rapid rate. Consequently, the use of enclosure air conditioners to cool telecom equipment is becoming almost standard practice.

Telecom Enclosure Needs

Because most telecom equipment operates at 48 volt DC, incoming AC power must be converted to DC. So in addition to the need to keep communication equipment cool, the additional heat load of the rectifiers and power supplies must be taken into consideration. It is also common to provide battery backup to power critical equipment through utility outages.

Most enclosures will be operated in accordance with the GR-3108-Core class 1 specification that specifies a maximum enclosure temperature of 104°F and a minimum of 41°F. This temperature range is not conducive to long battery life. The optimum temperature for lead acid based batteries is 77°F. This is an important consideration because battery life is halved for every 15°F temperature increase above 77°F. This means that it is essential to control the enclosure temperature as close to 77°F as is possible, and except for large enclosures where different temperature zones are practical, this becomes the target temperature for the telecom enclosure.

Ambient Temperatures

Many telecom enclosures are located outdoors and subject to the effects of solar radiation and natural ambient temperature variation. Because of this, the internal temperature of an outdoor telecom enclosure will vary over a wide range, a situation that is not ideal. It is far better to control the enclosure temperature over a narrow range around the battery optimum temperature and, in most instances, the most effective solution is enclosure air conditioning. It is also wise to prevent the enclosure temperature from falling too low as this is also detrimental to the standby batteries. To avoid this, enclosure air conditioners can be fitted with optional heating systems to ensure the enclosure temperature is kept closer to its optimum operating temperature.

Dirt and Dust

The other enemy of telecom equipment is dirt and dust. This requirement means that telecom enclosures located in dusty areas should be provided with enclosures that are sealed against dirt. This then imposes a requirement for a closed loop cooling solution that can only be met by air conditioning or air to air heat exchangers.

Harsh Weather

Telecom equipment is vulnerable to damage if allowed to get wet. In locations that are subject to high winds, rain, sleet and snow, special precautions need to be taken to ensure that windblown water does not enter the enclosure.  Although it is possible to use a weatherproof ventilated enclosure, such systems are far from ideal, and the most effective way to seal an outdoor enclosure is to use a sealed NEMA Type 4 enclosure. As with dirt and dust, a closed loop cooling solution is required for telecom enclosures that are subject to harsh weather.

Alternative Cooling Solutions

There are three primary enclosure cooling solutions that can be used. These are forced or natural ventilation, heat exchangers and air conditioning. The simplest, but least effective solution is forced or natural ventilation because the enclosure temperature will always be several degrees higher than the ambient air temperature. This in turn is invariably higher than the optimum standby battery temperature.

The next best alternative is a closed loop air to air heat exchanger. The closed loop cooling means the enclosure will be sealed, preventing the ingress of dirt and dust. However, air to air heat exchangers, like fans, remove heat, they do not actively cool, so an air to air heat exchanger is only viable if the enclosure is in a location with a moderate ambient temperature range.

The most practical and universal solution suitable for high heat loads, tough ambient conditions and high ambient temperatures is an enclosure air conditioner. Enclosure air conditioners are available to suit different enclosure sizes with a wide range of cooling capacities. Of particular interest are the 48 volt DC air conditioners that can operate directly off the standby batteries. With these models, enclosure cooling does not suffer during power outages and the overall system efficiency is higher.

Making the Right Choice

It’s vital that telecom equipment is provided with adequate cooling to ensure that the recommended enclosure temperature is not exceeded. Equally, it is essential to keep the temperature of standby batteries as close to 77°F as possible. In most circumstances, the most appropriate cooling solution is an enclosure air conditioner due to its ability to maintain a controlled temperature under all conditions. For further information on Thermal Edge telecom enclosure cooling solutions, contact our Sales Team and find out how our air conditioners will give you peace of mind.