Project Overview

Working with Burlington Engineering, MasterTherm delivered a high-efficiency heated-ventilation upgrade by modernising the rooftop ventilation plant to improve both heating and summer comfort for the offices below.

Scope of Works

• 2 × MasterTherm BA60iP inverter heat pumps (≈30 kW units)
• Buffer vessel decoupling source and distribution for stable coil temperatures
• 2 × Atrea Duplex 12000 Roto AHUs with integrated heating (and seasonal cooling) coils
• Full system design, integration, commissioning and controls interface

System Description

The BA60iP units modulate via inverter control, with lead/lag rotation to sustain high COPs and resilience. A buffer vessel ensures stable LTHW to the AHU heating coils while preventing short-cycling.

Each AHU uses a rotary heat-recovery wheel to reclaim exhaust energy. Supply-air temperature is controlled via PID to maintain comfort; frost protection safeguards coils. Where present, the AHU cooling coil is served by the building’s chilled-water plant for summer operation.

Open-protocol integration (Modbus/BACnet) provides BMS visibility, alarms and trending; fans operate on VSDs for low energy and fine control.

Project Results & Benefits

• Reduced carbon intensity through high-efficiency heat-pump heating and heat recovery
• Improved occupant comfort with responsive supply-air temperature control
• Lower maintenance and quieter rooftop plant with inverter technology
• Delivered on time with full commissioning and handover for day-one performance

Technical Highlights

• Rotary heat-recovery wheel typically achieves 75–85% sensible efficiency, cutting ventilation heating load.
• EC/VSD fans with pressure tracking reduce fan energy and noise in partial-load conditions.
• LTHW design temperatures commonly 45/35–50/40 °C for high seasonal efficiency while maintaining comfort.
• Coil selection and control valves sized to maintain stable ΔT and avoid hunting at low load.
• BMS trend logs enable fine tuning of SA temperatures, wheel speeds and pump VFD setpoints.

Energy & Carbon (SEAI)

By combining heat recovery with inverter heat pumps, ventilation heating demand and plant input power are both reduced, translating into meaningful CO₂ savings versus legacy gas-fired AHU coils.

• Supports SEAI public‑sector energy objectives and reporting.

Approach is compatible with SEAI EXEED methodologies (M&V, lifecycle focus).