Retrofit cooling solutions: a sustainable approach to year-round indoor climate comfort

Key considerations for retrofitting cooling systems

Retrofitting a cooling solution presents a few unique challenges, including space limitations, existing infrastructure constraints, the building’s insulation level, and cost-effectiveness. So it’s important to carefully evaluate various key factors to ensure you can implement solutions that enhance cooling performance while maintaining sustainability. The key considerations for selecting an appropriate retrofit solution include:

• Energy efficiency: new systems should be energy efficient to minimize operational expenses as well as the building’s carbon footprint.
• Regulatory compliance: stricter energy standards and local building codes call for the adoption of innovative and sustainable solutions.
• Building compatibility: older buildings might require additional modifications, such as extra insulation, for optimal performance of the heating and cooling system. Moreover, the building’s use and occupants’ needs have a strong influence on the choice of the most suitable solution.
• Compatibility with existing systems: when retrofitting cooling, you need to ensure the new solution integrates smoothly with the building’s current infrastructure.
• Efficiency in diverse climates: a cooling solution must be chosen based on how well it performs in different seasonal conditions. A passive cooling system will, for example, most likely be insufficient in a warmer, southern climate.
• Budget: some retrofit solutions require a higher initial investment but, when combined with an efficient energy source, users can enjoy significant energy savings over time. Weigh the upfront costs against the long-term savings to find the best solution that matches the project’s budget.
• Minimal disruption: retrofit projects often take place in occupied buildings, so minimizing disruption is important.

Retrofit cooling solutions

With roughly 2 billion air conditioning units currently in operation worldwide, it’s safe to say that this is one of the most commonly used solutions to integrate cooling in existing buildings.¹ While air conditioning certainly has its benefits, there are also alternative retrofit cooling solutions that can enhance efficiency and sustainability. These include:

1. Underfloor cooling

Underfloor cooling operates by circulating chilled water through a network of pipes embedded beneath the floor surface. It’s generally used in a combined system where underfloor heating is the main functionality and cooling is a support option to create a cooler floor that makes the room feel more comfortable in summer.

So if an underfloor heating system is already integrated in the building, you can easily retrofit it with the right control for cooling. If, on the other hand, such a system is not yet in place, the installation might require floor modifications, which may not be feasible in all retrofit projects. Underfloor heating systems with a low installation height such as our ts14 R or klettjet R renovation system can in this case offer a suitable solution for heating in winter and cooling in summer. This is a dry cooling system, meaning there is no condensation.

Underfloor cooling provides passive cooling by absorbing heat through the floor and lowers the room temperature 3 to 5°C compared to an uncooled room. It works well with a reversible heat pump and operates silently, which makes it ideal for residential spaces and offices. Our in-house calculation experts are happy to help you determine the system’s cooling capacity and offer tailored advice for the application in your project.

Learn more about underfloor cooling

2. Fan-assisted radiators

Fan-assisted radiators operate similarly to traditional panel radiators but are equipped with built-in fans that enhance airflow and create a heat output that is up to 60% higher than a standard radiator. This makes them very suitable for low-temperature heating. The added benefit of a fan-assisted radiator, such as our Ulow E2, is that it also has a dry cooling function that creates a cool breeze in summer in combination with a reversible heat pump so that you can enjoy a pleasant indoor climate year-round.

Whereas an air conditioning unit uses a compressor and refrigerant cycle, a fan-assisted radiator relies on circulating ambient air, meaning it has a lower environmental impact. Of course, you need to consider that a fan-assisted radiator cools passively, and therefore can’t reduce the room temperature as much as an actively cooling air conditioner.

Because of its compact size, a fan-assisted radiator is a good option for renovation projects where the system temperatures drop and old radiators need to be replaced. Moreover, our Ulow E2 has middle, left, and right connections, which is very interesting in case of a retrofit as you don’t have to change the pipe system. This allows you to easily replace older panel radiators without much construction work.

Fan-assisted radiators are particularly suitable for medium to large rooms, so they are most often used in residential properties and small commercial spaces. They’re not suitable for large-scale cooling.

Discover our fan-assisted radiators

3. Fan coil units

Fan coil units are equipped with a heat exchanger (coil) through which hot or chilled water flows. This means the same device can be used for heating as well as active cooling. If you want to use the active cooling function, it’s important to also install a condensate drain and to fit it with a siphon as an odour trap. If condensate-free / dry cooling is implemented, external dew point monitoring is required. The cooling capacity is lower in this case.

A fan coil unit, such as our iVector S2, operates optimally when paired with a reversible heat pump or a combination of a condensing boiler and chiller (cold water generator). Moreover, the iVector S2 can be mounted on the wall, ceiling or floor or even integrated into the wall or ceiling. This installation flexibility is very interesting for retrofitting. The compact design is furthermore ideal for renovation projects with limited space.

Fan coil units are often used in commercial buildings, such as offices and hotels, but they are also ideal for schools, retail and many other commercial premises, where both heating and cooling are needed. More and more frequently fan coil units are being installed in private residences as well.

Learn tips and tricks for installing the iVector S2 fan convector

4. Heat pumps

Heat pumps are a versatile and energy-efficient solution that can provide both heating and cooling in a single system. In winter, they extract heat from the outdoor air or ground. In summer, their operation is reversed and the heat is extracted from the room to facilitate cooling. They are energy-efficient and work with renewable energy sources, which reduces both energy costs and carbon emissions.

Air-to-water heat pumps integrate well with underfloor cooling, fan-assisted radiators, and fan coil units to enhance overall cooling performance in retrofit applications. Although its installation might require space for an external unit, which can be a challenge in urban retrofits, a heat pump is a very interesting option for older buildings needing an energy-efficient cooling solution without major infrastructure changes. However, the building’s insulation does need to meet modern energy standards for the heat pump to operate as efficiently as possible.

The air-to-air heat pumps in our range are also an increasingly popular retrofit cooling solution that offers both energy efficiency and versatility.

A heat pump is suitable for both residential and commercial retrofits and is often used in large-scale renovation projects where long-term energy savings justify the investment.

Read more about combining a heat pump with radiators

Conclusion

As the demand for energy-efficient cooling solutions continues to grow, it’s important to familiarize yourself with the various retrofit options that align with overall sustainability goals. Emitters such as underfloor cooling, fan-assisted radiators, and fan coil units on the one hand, and generators such as heat pumps each offer unique advantages. By selecting the most appropriate solution, HVAC professionals can significantly improve energy efficiency, reduce environmental impact, and enhance indoor comfort in existing buildings.

If you have any questions about this topic or would like tailored advice for a specific retrofit project, please don’t hesitate to reach out to our experts. We are always happy to help and are proud to offer a comprehensive range of products that can be easily combined to create a complete heating and cooling solution.

Sources:
1. https://www.iea.org/energy-system/buildings/space-cooling