Sheraton Hotel Athlone has taken a bold step in sustainability by implementing a state-of-the-art simultaneous heating and cooling system. This innovative energy solution uses advanced heat pump technology to recover and repurpose waste energy—providing year-round comfort, reducing operational costs, and dramatically lowering the hotel’s carbon footprint.

Project Overview

The project involved the full replacement and redesign of the hotel’s traditional heating and cooling plant. Central to the upgrade is a simultaneous heating and cooling loop powered by MasterTherm AQ90i inverter heat pumps, combined with a high-temperature water-to-water heat pump plant.

Instead of wasting heat during cooling, this system captures and reuses it—converting it into high-grade heat for domestic hot water (DHW) and space heating throughout the building.

Scope of Works

• Installation of 8 × AQ90i MasterTherm air-to-water heat pumps for simultaneous heating and cooling
• Integration of a water-to-water high-temperature heat pump plant room using rejected heat as a free energy source
• Installation of 5 × AQ75ZHX high-temp MasterTherm heat pumps to raise water temperature to 70°C
• LPHW (Low Pressure Hot Water) distribution throughout the hotel for heating
• Smart control and automation via integrated PLC and BMS platform

Heat Pump System Overview

• Simultaneous Heating & Cooling Loop
• 8 × AQ90i Inverter Air-to-Water Heat Pumps
• Deliver simultaneous heating and cooling to various hotel zones
• Heat rejected during cooling is captured and reused, rather than vented
• Inverter compressors respond dynamically to demand for maximum efficiency
• Heat Recovery to High-Temperature Heating
• 5 × AQ75ZHX Water-to-Water Heat Pumps
• Use the recovered low-grade heat as a thermal source
• Elevate water temperature to 70°C
• Serve LPHW distribution systems for:
• Space heating
• Domestic hot water preheat and storage
• Integration with fan coils or AHUs where required
• Intelligent Control & Monitoring
• All systems are managed via a fully integrated MasterTherm PLC-based control platform, allowing:
• Simultaneous load balancing between heating and cooling demands
• Real-time energy optimisation and setpoint control
• Live monitoring, fault alerts, and system analytics
• Seamless integration with the hotel’s Building Management System (BMS)

Project Results & Benefits

• This highly efficient and intelligent system delivers transformative performance and sustainability outcomes.
• Zero-Energy Waste Design
• Cooling energy is never lost—heat is reclaimed and repurposed
• Virtually eliminates the inefficiencies of traditional separate systems
• High-Efficiency Domestic Hot Water & Heating
• Water is heated up to 70°C using recovered heat
• Provides reliable space heating and DHW even during peak demand
• Carbon Emissions Reduction
• Major reduction in fossil fuel usage and CO₂ output
• Aligns with national and EU sustainability targets
• Guest Comfort & Climate Control
• Consistent, quiet operation with zoned temperature control
• Simultaneous heating and cooling provides flexible indoor comfort
• Operational Savings & Reliability
• Lower energy bills from efficient heat reuse
• Modular system design simplifies maintenance and future upgrades

Tech Notes & Smart Control

• AQ90i simultaneous heat‑cool recovers ‘waste’ condenser energy and feeds AQ75ZHX high‑temp plant—minimising chiller/boiler run hours.
• Cascaded control balances LPHW and DHW preheat/storage while avoiding conflicting loads.
• BMS-linked PLC provides load sharing, fault isolation, and tariff-aware scheduling (where enabled).

Guest Experience & Operations

• Uniform comfort across meeting spaces even with mixed calls for heating and cooling.
• ‘Zero-energy-waste’ loop supports quiet operation and lower plant room temperatures.

Energy & Carbon (SEAI)

• Switching from fossil-fired plant to high-efficiency heat pumps reduces on‑site combustion (Scope 1) and cuts overall CO₂ per guest‑night.
• Heat recovery (where fitted) further lowers electrical input per kWh of useful heat or DHW.
• Aligned with SEAI guidance for decarbonising hospitality; suitable for EXEED‑style M&V and public‑sector style reporting where applicable.
• Benefits grow as the Irish electricity grid continues to decarbonise, improving the carbon intensity of delivered heat over time.