Location: Cadiz, Spain

ASHRAE Weather File Type: 3C (Warm-Marine Mediterranean)

HVAC System: VRF System

Rating System: LEED v4 Renovation

Certification Level: Platinum

Project Description

• A resort in Spain wanted to refurbish/renovate their building in line with the latest green building standards and hence targeted the LEED Silver certification.
• In line with this requirement, the project had targeted a minimum of 10 credit points as per the EA: Optimize Energy Performance Credit.
• The challenge was to secure at least 24% energy savings vs the ASHRAE 90.1-2010 base case.
• “Since the building’s envelope was already fixed, optimizing this was not an option.
• Hence, the following became the areas of focus:
• Upgrading Lighting Fixtures & Including Lighting Controls
• Retrofitting the Air-Conditioning system

Energy Conservation Measures Identified

• Energy Efficient LED Lighting with Occupancy Sensors
• VRF systems with a cooling COP of 3.6 and a heating COP of 4.7.
• AHUs that have VAV (Variable Air Volume) fans

Energy Simulation

Since no changes were made to the existing envelope, the U-Values for the baseline envelope and the proposed case envelope were modelled exactly the same. In order to optimize the energy savings, the operating schedule, the equipment and lighting operational fractions were taken into consideration. Furthermore, the VRF performance curves were also taken in such a way that they replicate how the COP varies with the cooling load and also the ambient temperature.

Results

The project was able to achieve around 34% energy savings versus the ASHRAE 90.1-2010 base case and hence achieved 14 LEED credit points.