# Presentation: 151886

## CNN Center

**John Hester**
**Turner Properties, Inc.**

## CNN Center

**Built in 1975**
**1,583,000 square feet on 18 floors**
**Five structures joined by a common atrium**
**Multiple building uses**
**hotel, five cable networks, retail & food court, computer/data center, & office space**
**Building operated 7 days a week, 24 hours a day**

## CNN CenterPre-1994 Cooling Equipment

**Main plant - three 1200 ton centrifugal chillers **
**with 0.9 kw/ton efficiency, R-500 refrigerant, installed in 1975**
**Secondary plant - two 300 ton centrifugal chillers **
**cool the CNN Tower, 0.65 kW/ton efficiency, R-11 refrigerant, installed in 1986**
**Five cooling towers installed in 1975**
**Constant volume air distribution system**
**older areas (circa 1975) multi-zone units**
**newer areas (circa 1983) use VAV boxes**

## CNN CenterOriginal Building Envelope & Lighting

**R-10 walls, with R-5 to R-10 roof**
**Mostly double-glazed, bronze tinted windows with aluminum frames**
**Primarily 40 Watt fluorescent light fixtures with T-12 lamps and electronic ballasts**
**Some incandescent down-light fixtures**
**Motion detectors added in 1993**

## CNN CenterProject Scenario

**HVAC systems being maintained and upgraded over time**
**Expansion of facility decided on in late 1995**
**addition of two new networks and a new studio**
**two of the original 1200 ton chillers replaced in 1994 with 1500 ton chillers**
**need to replace third chiller & upgrade capacity**

## CNN CenterProject Challenges

**Wanted operational flexibility**
**Wanted to capitalize on real-time pricing benefits**
**Needed emergency cooling & electrical generation**
**Building must be kept operational 24 hours a day throughout all retrofit work**
**Need to serve new network loads**

## CNN Center System Solutions

**Three new chillers, two electrical & one gas-engine driven**
**One new cooling tower added**
**Back-up electrical generator added**
**Chilled water piping balancing**
**Air handler units converted & upgraded to direct digital controls**
**Lighting load reductions made**

## CNN CenterNew Chiller Plant

**Two York 1500 ton electrical centrifugal chillers**
**added in 1994, 0.6 kW/ton efficiency, R-22 refrigerant**
**One York/Caterpillar 1800 ton gas-engine-driven chiller**
**added in 1996, 2.03 COP, R-134a refrigerant**
**New cooling tower added for redundancy**
**Secondary chiller plant **
**now used as backup for CNN studios & data center**
**emergency electrical generators installed**

## CNN CenterChiller Piping

**Constant volume primary piping system **
**small plant piped to more critical studio & network loads**
**dedicated chilled water pumps for each chiller**
**Unbalanced chiller loads discovered**
**flow test and analysis revealed piping wasn’t large enough for north part of building**
**increased pipe sizes saved having to run backup plant to meet loads**

## CNN CenterOther HVAC Improvements

**Air handler units being upgraded **
**variable air volume diffusers  **
**variable speed drive controls**
**Pneumatic controls being replaced with direct digital controls**
**Hotel hot water **
**future ability to preheat through plate heat exchanger with the gas-driven chiller’s jacket**
**new shell & tube heat exchanger for instantaneous hot water from building steam **

## CNN CenterLighting Improvements

**T-12 lighting fixtures de-lamped from 4 to 2 lamps per fixture**
**Electronic ballasts added**
**Incandescent down-lights replaced with fluorescent PL fixtures**
**Motion sensors previously installed in offices**

## RTP rates are two-part tariffs
first part is standard bill based on the Customer Baseline Load (CBL)
second part charges the prevailing real-time price for energy use above the CBL
refund at real-time prices if under the CBL
CBL charges are usually higher than real-time prices
Gas chiller allows for a lower CBL
Competition led to cost savings on both electric and gas operation

**RTP rates are two-part tariffs**
**first part is standard bill based on the Customer Baseline Load (CBL)**
**second part charges the prevailing real-time price for energy use above the CBL**
**refund at real-time prices if under the CBL**
**CBL charges are usually higher than real-time prices**
**Gas chiller allows for a lower CBL**
**Competition led to cost savings on both electric and gas operation**

## CNN CenterElectric Energy Use Comparison

## CNN CenterIntegrated Economics

**Cooling tower & lighting measure savings unknown**
**Lower payback measures help reduce overall payback**

## CNN CenterProject Results

**Operational flexibility provided by the gas chiller**
**Reliable backup systems provided**
**Higher efficiencies of new chillers provides substantial savings**
**Loads being met thoughout existing building and expansion**
**Energy and utility bill savings**