In indoor base transceiver station (BTS) site, air conditioner contributes towards substantial portion of total site energy requirement.  This energy can be conserved by converting an indoor site to outdoor site i.e. by removing the air conditioner from the site while continuing to keep the BTS inside the shelter. To make this possible, a free cooling unit (FCU) needs to be installed for removing the shelter heat instead of cooling by air conditioner

A twin fan having cumulative 2000 CFM solution is designed for indoor to outdoor BTS conversion site. This solution is suitable for keeping the shelter within +5 C over ambient temperature range. Following changes to existing site will be required to carry out this solution:

• Removal of existing air conditioner
• Installation of FCU inlet and outlets
• Cabinet for transmission rack/3G/4G/Synchronous Digital Hierarchy equipment
• Fans fail alarm for each fan

Benefits:

• Reduction of energy cost
• Non movement of BTS and hence non involvement of active equipment providers team
• No downtime required
• Faster indoor to outdoor conversion rate

In India with grid deficiency, FCU acts like a thermal storage device supporting green energy efficiency thus by reducing usage of diesel gensets and hence reduction in carbon foot prints by building green future.

(Contributed by B. Madhu Babu, Head Electrical Design, Bharti Infratel Limited)