How Internally or Externally Positioned AHUs Deliver Efficient Heating Without Extensive Ducting
Air Handling Units (AHUs) play a critical role in modern commercial and industrial HVAC systems. While traditionally associated with ventilation and cooling, AHUs are increasingly used as primary heat delivery systems, particularly when paired with temporary boilers, heat pump chillers, or district heating connections.
At Ideal Heat Solutions, we deploy AHUs as part of engineered temporary and planned HVAC solutions across hospitals, commercial buildings, industrial sites, and complex live environments. Whether installed internally or externally, AHUs offer a highly flexible alternative to large, ducted heating systems — delivering controlled heat efficiently, with minimal disruption and faster installation.
This article explores how AHUs work, how they can be positioned within a building or externally, and why they are often a more efficient and practical solution than traditional ducting or radiator-based heating — particularly during refurbishments, outages, and low-carbon transitions.
What Is an Air Handling Unit (AHU)?
An Air Handling Unit is a mechanical system designed to condition and distribute warm or cold air within a building.
When combined with a temporary boiler or heat pump, they offer a standalone heating solution.
This makes AHUs especially suitable for temporary heating projects, phased refurbishments, and sites where internal plant space is limited.
Using AHUs for Heating — Not Just Ventilation
While AHUs are commonly associated with fresh air and ventilation, their ability to deliver heat is often underestimated.
When supplied with hot water from a temporary boiler or heat pump system, AHUs can function as highly effective space heating units, delivering warm air evenly and efficiently across large areas.
Because air has a fast response time compared to water-based emitters, AHUs are particularly effective where:
- Fast heat-up is required
- Internal temperatures must be tightly controlled
- Occupancy varies throughout the day
This makes them ideal for healthcare facilities, education buildings, logistics warehouses, film studios, workshops and industrial units.
Internal vs External AHU Positioning
One of the key advantages of AHUs is their flexibility in positioning. At Ideal Heat Solutions, AHUs are routinely installed either inside the building or externally, depending on site constraints and project requirements.
Internally Positioned AHUs
Internal AHU installations allow heating and ventilation to be delivered directly within the occupied space, significantly reducing the need for long duct runs.
This approach offers several benefits:
- Faster installation with minimal structural disruption
- Reduced ducting losses
- Improved thermal efficiency
- Easier access for maintenance and adjustment
- Better control over air distribution and comfort
Internally positioned AHUs are commonly used in:
- Large warehouses
- Distribution Centres
- Film Studios
By placing the AHU close to the point of use, heat is delivered more efficiently and with greater control.
Externally Positioned AHUs
Externally positioned AHUs are typically used where internal space is restricted or where plant separation is required.
External AHUs can be:
- Roof-mounted
- Positioned at ground level
- Installed within temporary enclosures or weatherproof housings
When combined with external boilers or heat pump chillers, this configuration creates a self-contained heating and air delivery system that can be connected into the building with minimal internal impact.
External AHUs are particularly effective for:
- Construction and refurbishment projects
- Temporary heating for live buildings
- Industrial environments
- Emergency heating deployments
With short duct penetrations into the building, this approach avoids the complexity of full ducted systems while maintaining excellent performance.
Pairing AHUs with Temporary Boilers
AHUs integrate seamlessly with temporary boiler hire solutions, forming a robust heating system without the need for permanent plant.
At Ideal Heat Solutions, AHUs are commonly paired with:
- Slimline condensing boilers
- Packaged boiler plant rooms
- Low-temperature heating systems
- Plate heat exchangers for system separation
This configuration allows heat to be generated externally and delivered internally via AHUs, maintaining comfort and compliance during:
- Plant room refurbishments
- Emergency breakdowns
- Capacity shortfalls
- Seasonal demand increases
Because AHUs distribute heat via air rather than water emitters, they can maintain consistent temperatures even when system loads fluctuate.
AHUs and Heat Pump Chillers
As heat pump technology becomes more prevalent, AHUs are increasingly used as the ideal heat emitter for low-temperature heating systems.
Heat pump chillers operate most efficiently at lower flow temperatures than traditional boilers. AHUs are well suited to this because:
- Large coil surface areas maximise heat transfer
- Air-based delivery compensates for lower water temperatures
- Variable fan control enables precise comfort management
When paired with heat pump chillers, AHUs can deliver:
- Highly efficient heating
- Reduced carbon emissions
- Compliance with sustainability targets
- Future-ready HVAC infrastructure
This makes AHUs a key component in decarbonisation strategies across commercial and public sector buildings.
Energy Efficiency and Performance
AHUs can deliver excellent efficiency when correctly specified and installed.
Key performance benefits include:
- Quick heat-up times
- Even temperature distribution
- Reduced reliance on high-temperature water
- Compatibility with modern controls and BMS systems
At Ideal Heat Solutions, AHUs are integrated with control strategies that allow:
- Zoned temperature control
- Demand-based airflow
- Integration with Trend BMS or Trane Connect
- Remote monitoring and optimisation
This ensures systems operate efficiently throughout the hire period, reducing energy consumption and operating costs.
Applications Across Commercial and Industrial Sectors
AHUs are used across a wide range of sectors where flexibility, speed, and reliability are critical.
Common applications include:
- Hospitals and healthcare facilities
- Universities and schools
- Commercial offices
- Industrial manufacturing sites
- Warehouses and logistics hubs
- Temporary buildings and modular spaces
In each case, AHUs provide a practical way to deliver heating and ventilation without reliance on permanent infrastructure.
Compliance, Safety, and Operational Reliability
Heating and ventilation systems must meet strict safety and compliance requirements — particularly in occupied and critical environments.
Ideal Heat Solutions ensures all AHU deployments are:
- Designed by experienced HVAC engineers
- Installed by qualified professionals
- Fully commissioned and tested
- Integrated with appropriate controls
- Supported with 24/7 technical assistance
Whether installed internally or externally, AHUs are selected and configured to meet building regulations, workplace safety standards, and sector-specific requirements.
Why Choose Ideal Heat Solutions for AHU Hire?
At Ideal Heat Solutions, AHUs are not supplied as standalone units — they form part of a fully engineered heating and air delivery solution.
Clients choose us because we provide:
- Expert system design
- Flexible internal or external AHU positioning
- Seamless integration with boilers or heat pumps
- Quick mobilisation for emergencies and planned works
- Nationwide coverage with local engineering support
Our approach ensures AHUs deliver reliable, efficient heating without unnecessary complexity.
Conclusion
Air Handling Units offer a highly flexible, efficient, and practical solution for delivering heating in commercial and industrial buildings. Whether installed internally to minimise ducting or externally as part of a temporary energy centre, AHUs provide fast response, excellent comfort control, and compatibility with both boilers and heat pump systems.
As buildings evolve and heating strategies move toward lower-carbon solutions, AHUs are becoming an essential part of modern HVAC design.
If you require temporary heating, ventilation, or a fully engineered AHU solution, Ideal Heat Solutions can design and deliver a system tailored to your building, your timeline, and your operational requirements.
Frequently Asked Questions: Air Handling Units (AHUs)
What is an Air Handling Unit (AHU)?
An Air Handling Unit (AHU) is a HVAC system used to circulate, filter, heat and sometimes cool air within a building. When paired with a boiler or heat pump, AHUs can act as a primary heat delivery system, supplying warm air efficiently across commercial and industrial spaces.
Can AHUs be used for heating as well as ventilation?
Yes. AHUs are highly effective for heating when connected to a hot water source such as a temporary boiler or heat pump chiller. Heated air is delivered directly into the space, allowing fast heat-up times and even temperature distribution.
Are AHUs more efficient than traditional radiators or ducted systems?
In many applications, yes. AHUs can be more efficient because they:
- Deliver heat quickly via air rather than relying on slow thermal mass
- Operate effectively at lower water temperatures
- Require less extensive ducting when positioned close to the space
This makes them particularly suitable for temporary heating, refurbishments, and low-carbon systems.
Can AHUs be installed internally as well as externally?
AHUs can be installed either internally or externally depending on site constraints. Internal AHUs reduce ducting and heat losses, while external AHUs are ideal where internal plant space is limited or where a temporary energy centre is required.
Do AHUs work with heat pump heating systems?
Yes. AHUs are especially well suited to heat pump systems because they perform efficiently with low flow temperatures. Large coil surface areas and controlled airflow allow AHUs to deliver comfortable heating without the high temperatures required by traditional radiator systems.
Are AHUs suitable for temporary heating projects?
Absolutely. AHUs are widely used in temporary and planned heating applications, including plant room refurbishments, emergency outages, and phased construction projects. They can be deployed quickly and integrated with temporary boilers or heat pumps.
What types of buildings use AHUs?
AHUs are commonly used in:
- Hospitals and healthcare facilities
- Universities and schools
- Industrial and logistics buildings
- Temporary and modular structures
They are particularly effective in large or open-plan spaces where consistent air distribution is required.
Does Ideal Heat Solutions provide full AHU system design and installation?
Yes. Ideal Heat Solutions supplies AHUs as part of a fully engineered solution, including system design, boiler or heat pump integration, controls, commissioning and ongoing technical support. Systems can be tailored for short-term hire or longer-term projects.
To learn more or book a free site survey, contact Ideal Heat Solutions today.
📞 CALL US: 0808 3014 183
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