Enhancing Comfort and Efficiency with Perimeter Systems

Architectural photography often highlights the open, airy feeling a space gets from floor-to-ceiling glass. What it doesn’t capture is what all that glass feels like on a cold winter’s day. 

Perimeter systems are the unsung heroes of HVAC design, quietly working to maintain thermal comfort along the vulnerable edges of buildings. These systems combat heat loss or gain through exterior walls and windows, preventing uncomfortable drafts and temperature fluctuations. 

By strategically placing perimeter heating or cooling sources, property developers can optimize energy efficiency and enhance occupant comfort. Choosing the right perimeter system is crucial for achieving optimal supplemental heat. At AirFixture, we design our perimeter systems to meet the needs of each unique project. Creating a comfortable and efficient building environment requires understanding the strengths and weaknesses of different types of HVAC systems.

Importance of Having a Perimeter System

A well-designed perimeter system is essential for several reasons: 

Thermal Comfort: Perimeter systems create an insulated barrier that limits heat loss or gain and helps regulate the temperature of the air circulating throughout a space. In limiting loss and gain, perimeter systems prevent cold drafts and hot spots, ensuring consistent comfort for occupants. 

Energy Efficiency: These systems reduce the overall heating and cooling load, lowering energy consumption and reducing operating costs. As an added plus, they are easily accessible, creating less downtime when performing regular maintenance as compared to traditional overhead heating systems.  

Improved Indoor Air Quality: Some perimeter systems, like trench heaters, can help distribute fresh air and reduce indoor pollutants. 
 

Types of Perimeter Systems

Perimeter systems come in all shapes and sizes, but three major classifications of perimeter systems stand out from the rest.

Trench Heating Units:

Trench heaters are a popular choice for perimeter heating due to their space-saving design flexibility and effective heat distribution. These units are installed in floor, typically hidden from view by floor coverings. They operate by drawing in cool air naturally, heating it, and releasing warm air into the room. Trench heaters can be natural convection or fan-assisted, depending on the desired heating speed and distribution.  

 AirFixture offers trench heating units tailored to fit an individual project’s needs. Our Soho fan-assisted trench heaters can be either electronic or hydronic heating units and can be configured in an underfloor trench, along the wall or ceilings to accommodate design choices. 

• Space-saving: With the multiple configurations available, valuable floor space becomes available, unlike traditional radiators. This is another reason trench heaters are often chosen for retrofits of current systems.  

• Aesthetically pleasing: They can be seamlessly integrated into various interior designs, with endless variations on height, length, paint, etc. 

• Effective heating: They provide targeted heat directly to the perimeter where needed most and create an insulated barrier to protect from heat loss and gain, especially in spaces with large glass walls.  AirFixture trench heaters provide heat at a moderate comfortable temperature and have a zero clearance to combustibles. This means the user can sit a box of Kleenex on top of our high output electric SoHo Trench Heater. 

 Slab Heating Systems (SHS)

Slab heating offers heat distribution for exceptional comfort throughout an entire space, including the perimeter. Warm water or electric cables are installed throughout the slab, gently heating the entire floor surface. Slab heating systems provide even heat distribution and can be used for both heating and cooling.  

Comparison with trench heaters: 

• Installation: Slab heating systems require more extensive installation compared to trench heaters. Insulation under the slab is key to having a system that runs successfully.  

• Heating performance: SHS provides a slower but more even heating experience than trench heaters. The heat isn’t thrown as high, leaving room for heat loss and gain around the perimeter, especially in tall glass exterior buildings. SHS works best in residential installations. 

• Aesthetics: SHS are completely hidden, offering a clean and minimalist look. 

• Functionality: Installing the cables in the slab means that the layout of the space is committed, and you will lose future flexibility. Adding or moving rooms, appliances, etc. will require an experienced contractor and additional costs. 

Chilled Beams

Chilled beams are primarily used for perimeter cooling. They combine convection and radiant cooling to efficiently remove heat from a space. Chilled water circulates through the beams, using less energy than traditional air cooling. Active chilled beams often require integration with other HVAC systems for optimal performance. Passive chilled beams rely solely on natural convection. AirFixture offers both overhead and in-floor chilled beams. 

Comparison with trench heaters: 

• Installation: There is a higher initial cost for installation of chilled beams.  

• Quiet operation: They provide a quiet cooling solution, comparable to a trench heater.  

• Functionality: They can provide both heating and cooling, enabling year-round comfort. However, there is a possibility of condensation, which would require an additional humidity management system. 

What to Consider When Choosing a Perimeter System

With so many options to heat and cool a building perimeter, it may seem hard to choose the right solution for your unique needs. When comparing perimeter systems, we recommend comparing the systems’ efficiency and energy performance, design aesthetic and space considerations, and overall performance and occupancy comfort. 

Efficiency and Energy Performance

• Energy consumption: The cost of energy is always on the rise. Compare which systems require the least amount of energy to work effectively.  

• Efficiency ratings: Look for systems with high energy efficiency ratings to maximize cost savings. Take into account the system’s regular maintenance schedule as well to minimize costs over time.
• Energy-saving features: Consider features like variable speed fans, low water temperatures and advanced controls to optimize energy performance.

Aesthetic and Space Considerations

• Interior design: Choose a perimeter system that complements your building's aesthetic and complements the desired interior design. Some perimeter systems allow for customization to match the interior aesthetics better than others.  

• Space requirements: Evaluate the available space for installation and choose a system that fits your needs. If a raised floor is already planned, a trench heater might be the perfect fit to install for your project. 

• Installation flexibility: Consider the ease of installation and potential impact on room layout. Some perimeter systems can be installed in different forms from under the floor, to hung vertically to fit a wall.  

• Air quality: Consider the impact of each system on indoor air quality, especially for occupants with allergies, sensitivities or specific air quality standards. 

Heating/Cooling Performance

• Comfort levels: Assess the comfort provided by each system, considering factors like temperature distribution, response time and noise levels. 

• Heating/cooling distribution: Your perimeter system should create an environment that limits cold zones, excessive drafts, and varied temperature throughout an open space. 

Finding The Right Fit for Your Project 

Selecting the right perimeter system is essential for creating a comfortable, energy-efficient, and aesthetically pleasing building environment. Trench heaters offer a practical and efficient solution for perimeter heating. At AirFixture, we work directly with our clients to identify their perimeter heating and cooling needs and create a solution within your timeline and budget. To learn more about perimeter heating and cooling and to talk to an AirFixture engineer about your project, contact us today.