Telecom cooling failures spike every Indian summer. Learn why DC air conditioners and heat exchangers fail, and how to prevent costly BTS shelter downtime
Each May, the same phone call is received: a BTS has failed, the BTS site engineer has suspected a power problem, and after driving two hours to the tower, the actual problem is heat! Not a blackout. Not a hardware issue. All that was done was to warm up a place that the enclosure was never meant to withstand.
This is something we’ve seen happen in India over the years for outdoor cooling cabinets and indoor telecom cooling enclosures for operators and EPCs, and it’s been happening pretty much every year. Cooling failures are not accidental, they occur in line with time of year, location and often a few avoidable design decisions made long before summer.
Why Telecom Cooling Failures Spike Every Summer
Many of India’s telecom infrastructure equipment were never designed for the ambient temperature of 45°C. As outdoor air temperatures rise into the 40s, the air entering the cabinet or shelter is also hot before it ever gets into the cabinet or shelter touching the equipment that will create heat within the cabinet or shelter. A cooling system that is acceptable for the winter and monsoon seasons may not do as well during the summer. This difference is where failure occurs.
Here are some reasons repeatedly occurring on such sites:
- Undersized or mismatched DC air conditioners: The cooling unit needs to be a DC air conditioner, not an AC unit converted to operate on DC power, because most telecom cooling sites operate on -48V DC power supply. If a DC air conditioner cabinet is designed for an average condition instead of peak summer load, it has to run all the time, short cycles, and will wear out sooner — just when you need it most.
- ICT rack density outpacing airflow design: As more equipments are added to the same space, such as RF units, ICT rack space, batteries for backup systems, heat load per shelter continues to rise, while the cooling system is installed at commissioning and typically does not increase in size with it.
- Dust and filter neglect: As with Indian heat, summers also bring dust. A dirty filter on a DC air conditioner or heat exchanger isn’t a problem of just making it less efficient, it could also cause the unit to go into thermal cutout during the hottest time of the day.
- Choosing the wrong cooling method for the site: Not all sites require the same solution, and it is common and costly to have a heat exchanger installed in a site where a sealed DC air conditioner was actually required or a sealed DC air conditioner installed in a site where heat exchange was actually required.
The Real Cost of a Cooling Failure
A cooling failure doesn’t always walk on its own. A temperature alarm can quickly turn into a hard equipment shutdown — in a remote, unmanned location, “within hours” may turn to “within a day” before a technician can get there. If the company providing the telecom infrastructure has an SLA (Service Level Agreement) with strict downtime requirements, then there is a direct cost of the downtime, as well as the accelerated wear on all equipment inside the enclosure due to the heat event. One of the quickest methods to reduce the life spans of RF equipment, batteries and power supplies is repeated thermal cycling – hot, cool, hot again.
DC Air Conditioners vs Heat Exchangers: Choosing the Right Telecom Cooling Method
This is one concern that we are regularly asked by procurement and design teams, and unfortunately, it’s not a yes/no preference, but rather depends on the site.
For high heat load sites, humid and dusty environments, and when cooling is essential, a DC air conditioner is the best solution — such as BTS shelters or dense ICT rack deployments in humid and dusty environments.
A heat exchanger is a more passive or semi-passive approach that works well when the heat load is not as great, and the outside ambient temperature is not constantly extreme. Heat exchangers do not have moving parts or compressors, which could result in reduced maintenance throughout the life of the site, but are not a replacement for active cooling when ambient temperature and internal heat loads exceed a certain point. There are various types of heat exchangers that are appropriate to various enclosure sizes and heat loads, and the selection of the wrong heat exchanger is as expensive as not cooling at all.
In practice, the most effective sites are those that combine the two telecom cooling solutions: heat exchangers to provide basic thermal management plus an industrial air conditioner or a DC air conditioner sized for the actual peak loads of summer, rather than the average loads.
How to Prevent Cooling Failures Before They Happen
There are several common factors which make the sites get through the summer different:
- Size for peak load, not average load. Don’t design the DC air conditioner or industrial ac around the average hot day of the season, design it around the hottest day that it will realistically be exposed to.
- Build in redundancy on critical sites: For a site with no redundant cooling system, a single point of cooling failure is a risk multiplier – having dual-fan or dual-unit systems pay off the first time one unit fails.
- Maintain filtration on a fixed schedule: In India, dust intrusion is a known phenomenon – make maintenance of filters a regular practice, not a crisis management.
- Work with a heat exchanger manufacturer and/or a DC air conditioner supplier who is aware of the working conditions in India — it is very different from the working conditions in temperate zones.
- Reassess cooling capacity whenever rack density changes: If the load on the ICT rack has increased since commissioning, the original cooling design assumptions are likely to no longer be valid.
What to Look for in a Telecom Cooling Solutions Partner
Cooling is not a first class design consideration at every telecom manufacturer, as mismatches tend to occur when it is attached to the enclosure and rack layout after they have been finalised. Whether the telecom cooling cabinet is deployed in an outdoor shelter, or a shelter is built as a standalone, at Byteworx, thermal management is designed from the ground up.
When shopping for telecom cooling solutions partners in India, the difference between a reliable partner and the rest isn’t so much the spec sheet, but whether the cooling was designed to address the specific site’s heat load, dust exposure and duty cycle or was simply selected from a generic telecom products list. We’ve incorporated this site-specific concept in each and every enclosure we ship and have the same level of manufacturing standards as already trusted by Airtel and Jio and 500+ clients deployments.
Conclusion
Heat is not an unpredictable risk for Indian telecom cooling sites — it’s an annual certainty and each cooling failure we’ve experienced above relates to a design or maintenance decision that was made long before summer arrived. These are all basics and not advanced strategies, and all these will make the difference between sites that make it through the season and those that don’t: Size your DC air conditioner for peak load rather than average load; Make sure that the right heat exchanger is used for the site; Build in redundancy; Plan ahead for dust and filter maintenance.
When your team is considering implementing new cooling, scaling up an existing site, or just isn’t sure the current setup will be up to the challenge of this summer’s heat, it’s important to have a second opinion before you make that decision. Contact Byteworx team to discuss your site’s telecom cooling needs.