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Posted 06 August, 2026

Senior Mechanical Design Engineer (Renewable Systems)

OUTSOURCE CONSTRUCTION LTD
City of London, ENG, GB Full Time

Job Description


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Position: Senior Mechanical Design Engineer (Renewable Systems)

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Location: London/ Hybrid

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Salary: £75,000 - £90,000

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We are looking for a specialist Mechanical Design Engineer to lead the transition from fossil fuel combustion to Large-Scale Heat Pump Technology. You will be responsible for the "physics" of the system—ensuring that high-capacity heat pumps are integrated into hydronic circuits that actually deliver on their efficiency promises.

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  • Core Technology Focus1. Air Source Heat Pumps (ASHP)Cascade Systems: Designing multi-unit ASHP arrays for commercial peak loads.
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  • Defrost & Ambient Logic: Managing acoustic mitigation, airflow requirements, and defrost cycle impacts on system continuity.
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  • Bivalent Integration: Designing systems that integrate ASHPs with existing LTHW or backup heat sources.
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  • 2. Ground Source Heat Pumps (GSHP)Array Design: Coordinating borehole heat exchangers (BHE), horizontal loops, and thermal conductivity testing.
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  • Ambient Loops: Designing 5th Generation heat networks and "sharing" energy across multi-user sites.
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  • Passive Cooling: Leveraging ground temperatures for high-efficiency cooling integration.
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  • 3. Hydronic Architecture (The "Engine Room")Low-Temperature Hot Water (LTHW): Designing for Heat Pump efficiency (e.g., 45°C flow / 35°C return).
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  • Buffer & Separation: Precise sizing of buffer vessels and Low-Loss Headers to prevent short-cycling and maintain hydraulic separation.
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  • System Balancing: Specifying PICVs and variable-speed pumping to ensure optimal mass flow rates.
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  • Key Professional DutiesDetailed Modeling: Using IESVE or Hevacomp to ensure heat loss calculations meet BS EN 12831 standards.
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  • BIM Coordination: Utilizing Revit MEP for 3D spatial coordination of complex plant rooms.
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  • Technical Compliance: Ensuring all designs meet CIBSE CP1 (Heat Networks) and MIS 3005 (MCS) standards.
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  • Candidate ProfileTechnical Background: Degree-qualified (BEng/MEng) with a deep understanding of thermodynamics.
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  • Professional Status: CEng or MCIBSE preferred.
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  • Experience: You must have a proven track record of designing ASHP or GSHP systems—not just supervising them, but performing the actual hydronic and thermal calculations.
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