Resort Achieves 50% Energy Savings and Ample Guest Comfort With VRF Zoning Technology

Tamarijn Aruba All Inclusive (Tamarijn Aruba), Oranjestad, Aruba, is a resort that attracts discriminating vacationers from around the world. With 236 beachfront guestrooms, the 135,000-square-foot resort boasts an impressive average occupancy rate of 80 percent, with many days fully booked. Still, Tamarijn Aruba faced a situation dreaded in the hotel world: customer complaints. Guests reported a malfunctioning HVAC system, criticizing the air’s quality and moisture. The resort also had to cope with Aruba’s high energy costs. The result was an expensive HVAC system that didn’t meet the goals set for customer satisfaction.

Challenge: To select an HVAC system that would improve guest experience and lower energy costs.

To tackle this problem, an HVAC overhaul replaced the old system in twelve 2,800-square-foot guest buildings with a Variable Refrigerant Flow (VRF) zoning system from Mitsubishi Electric US, Inc. Cooling & Heating Division (Mitsubishi Electric). The system has paid for itself in just three years of energy savings, and the dreaded customer complaints about the HVAC system have turned into a steady stream of compliments.

Henk Swart, Tamarijn Aruba’s chief engineer, described the difficult situation caused by the old HVAC system. “The majority of guests are from the U.S. or Canada; guest expectations and usage of the AC systems are high.” The previous system, PTAC window units, were “aging, and as a result the resort had many issues/guest complaints.”

Patrick Nogera, HVAC sales engineer, Pro-Tec Mechanical Contractors Aruba NV (Pro-Tec), Oranjestad, designed and proposed the new system, and later assisted the mechanics during the installation. Nogera said the top two needs for the new system were guest comfort and cost and energy savings, including both energy use and the upfront installation cost. For the latter, the team analyzed the mean time to repair (MTTR) and mean time between failures (MTBF). “Together with Pro-Tec,” Swart said, “we decided on a certain standardization per building, finding an optimum balance between initial cost, guest impact during renovation and spare part/system availability (MTTR/MTBF analysis).”

“We also wanted to minimize the amount of outdoor units in our landscaping and minimize noise,” said Swart. Nogera explained that “there was not much room for condenser units and aesthetics were an issue.”

Among other factors, the resort was balancing cost, energy savings, guest comfort, aesthetics and noise. Given the number of factors being considered, the team completed a comprehensive test of three different HVAC systems. Nogera said, “Before winning the [VRF] project for all buildings, we first completed a [VRF] installation in one building so energy consumption could be measured. The resort had already done another building with a Mini Chiller system from Multiaqua. Comparing the existing (PTAC) units, Multiaqua and Mitsubishi Electric VRF, Mitsubishi Electric VRF was the winner. It was the best choice.”

“Mitsubishi Electric won the battle with flying colors,” Swart said. “It was a total package: proper design, installation, service and support.” Swart added that the quick delivery cycles were also key: “Being able to have equipment on site within weeks meant that as a resort we could start saving money sooner.”

The installation began and immediately presented a challenging time crunch. The resort needed to stay in operation as much of the time as possible, giving the installers “only three weeks for each building,” said Nogera. The installation fell into a rhythm, though, creating a smooth process. “The installation was also very easy because of the system’s small pipes that had minimal impact on the building,” said Nogera. Swart added that there were “no budget surprises.”

Since installation, it’s been smooth sailing at this beachfront utopia. “Key in our resort is of course guest satisfaction,” said Swart. “Since switching to the Mitsubishi Electric VRF solution, complaints on AC are down to a minimum. In fact, we receive many compliments on the indoor comfort nowadays.” Everything looks good to Nogera, too: “The product has exceeded all expectations. Hotel guests are happy about the comfort and the hotel itself is happy since there are so few issues with the equipment.”

Happiness is also due to the impressive energy savings. “We recorded a savings of 50 percent,” said Swart. “Our average electrical consumption went down from 20 kWh to 10 kWh per guestroom per day due to the VRF solution from Mitsubishi Electric. On split solutions we have seen similar savings (50 percent) when we went from non-inverter R22 splits to Mitsubishi Electric P-Series units.”

Solution: A VRF zoning system from Mitsubishi Electric curbed customer complaints while offering amazing energy savings.

These energy savings are also bringing the resort positive attention from programs like Earth Check, which promote and reward sustainable tourism and research. Swart said, “The energy savings on our AC systems with Mitsubishi Electric greatly contributed to receiving the Earth Check Silver Certificate in 2013.” The resort is currently pursuing 2014 certification.

All of this progress is especially impressive given the harsh marine conditions that the outdoor units face, including a heavy salt build-up. The units come pre-coated for coastal environments offering “an added protection,” said Swart. The rest of the job is completed by the frequent maintenance that the resort and Pro-Tec complete to “protect our investment.” Swart said that any added maintenance cost is “very much worth it because of the performance/comfort and lifecycle extension.”

Perhaps the greatest endorsement for the new HVAC system is the plan for future use. Swart said of their Mitsubishi Electric VRF zoning system, “with upcoming renovations and new builds, we are going to continue on this path. In fact, at present we are developing a new 60-unit apartment building and we have selected the super-efficient M-Series products as our AC of choice for this project.”