Building technologies are advancing every day. From smart glass that automatically dims to decrease heat gain from the sun during the day to rainwater collection and recycling, building owners have the unique opportunity to retroactively update their buildings to better fit their unique needs.
One of the most popular places to start when upgrading building systems is the heating unit. Today, one of the leading types of perimeter heating systems is called trench heating. Trench heaters, also known as baseboard heaters, finned tube radiators or recessed trench heaters, can help building owners increase occupant comfort while maximizing their energy efficiency and leaving a blank canvas for tenant improvement projects down the road.
For most of recent history, commercial buildings were heated with large central hot water boilers. These boilers produced really hot water about 180°F. That hot water was piped around the buildings to convective heaters (sometimes called radiators) that heated the spaces without using any fan power. That worked well because of the high temperature, but these old boilers were energy hogs. Many or most of these old systems have been replaced with new high-efficiency boilers that produce 120-140°F hot water. Now the existing perimeter finned tube or radiators put out about half as much heat into the room. Not only is capacity a problem, but the heat doesn’t get well distributed into the room. Fan-powered convectors will deliver 4-5 times the heat as the same convector without a fan. The air is delivered at a pleasant warm temperature (80-95°F) as compared to older systems delivering 160-180°F air that quickly rises to the ceiling.
How Trench Heaters Work
Trench heaters are a heating system that uses hot water, electric coils, or steam to discharge heated air into a space. These systems are installed in trenches that are dug into an existing floor or formed trenches when a new building is constructed. An easy solution for retrofitting buildings, they can also be installed vertically on the walls or even hung from the ceiling. The electric current, hot water, or steam is circulated through the trench heaters, and the fans blow the air across the perimeter space of the building. Because the trench heaters are typically installed along the perimeter, the heaters act as insulators for the rest of the building’s interior, reducing climate control loss. Trench heaters are especially ideal for atriums, high rises, and other spaces that utilize floor-to-ceiling glazing.
Short-term benefits of trench heating
- Occupant comfort: Trench heating consistently recirculates heated air into a room, creating a blanket of insulation that helps the room’s air distribution system stay consistent and minimize hot or cold spots.
- Reduced noise pollution: Trench heating systems are very quiet compared to larger overhead fans or finned tube radiators.
- The grilles can be walked over immediately after installation, accelerating a project’s process.
Long-term benefits of trench heating
- Energy savings: Trench heating is an efficient way to heat a building as the heat is distributed evenly along the perimeter space. Trench heaters also take advantage of low-temperature ground source heat pumps, allowing for better use of utility-provided water. These considerations can lead to significant savings on energy costs over time. According to a 2022 JLL report, buildings with considerable retrofits on MEP equipment experience 30% - 40% energy savings and logistics centers with similar retrofits experience 20% - 25% energy savings.
- Trench heaters can operate as stand-alone systems, or in addition to other HVAC systems.
- Reduced maintenance costs: Trench heating systems are very low maintenance. This means that there is less wear and tear on the system, which can lead to longer lifespans. It also lowers the amount of maintenance touchpoints that interrupt tenants’ leased areas. The main cleaning required can be accomplished by using a vacuum to suck up the accumulated dust.
- Increased property value: Trench heating is highly sought after by many buyers, due to its adaptability and aesthetic.
Using a trench heating system
The user interface of a trench heating system in a commercial real estate building is typically a simple thermostat that can be programmed to maintain a desired temperature. The system works very quickly to respond to changes in the temperature setting, typically within minutes. This makes trench heating a very efficient and comfortable way to heat commercial spaces.
The thermostat may also have additional smart features, such as the ability to control the fan speed or to set different temperatures for different areas of the building. The system can also be integrated with a building management system to provide centralized control and monitoring.
What to consider when switching to trench heating
If you are considering switching to trench heating for your existing building, here are some tips on how to evaluate the heating needs of your current building and assess your existing traditional heating system:
- If you are experiencing ineffective indoor climate control with abnormal humidity levels, hot and cold spots or draft zones, it may be time to consider trench heating as an alternative.
- If your building already has raised access flooring, trench heaters can quickly and easily be installed along the perimeter of the building without any major construction costs.
- Trench heaters are exceptionally effective at controlling temperatures along the exterior of buildings with large walls of glass windows. They are perfect for use in atriums, vestibules, large lobbies and wall-to-wall window coverage in office spaces.
- Gather information about your building's climate and energy usage. This includes the average temperature range in your area, the size of your building and your current energy bills.
- Inspect your existing heating system. Look for signs of wear and tear, such as leaks, rust or cracks.
- Define your budget and your long-term energy goals. How much are you willing to spend on a new heating system? What are your goals for energy efficiency and comfort?
- Partner with a reputable manufacturer: At AirFixture, we have decades of experience providing our clients with the latest heating and cooling technology from trench heating to underfloor air distribution systems. We work directly with building owners, developers, architects and engineers to deliver a unique solution for your building.
Once you have gathered this information, you can start to evaluate your heating needs and assess your existing system. This will help you determine if your current system is meeting your needs and if it is worth investing in a new system.
If you are just getting started, here are some easy questions you can ask yourself to assess your heating needs:
- Does your building use perimeter floor-mounted convectors?
- Does your building feature floor-to-ceiling glass windows?
- How comfortable is your building in the winter?
- Are there any cold spots in your building?
- What is the age of your current heating system?
- Has your boiler been updated to a more modern, efficient boiler?
How are trench heaters installed?
Trench heater installation is a simple process, but it is important to have a qualified contractor do the work. The contractor will need to cut the trenches, install the trench heaters, and connect the trench heaters to electric power, hot water, or steam system.
Trench heaters are installed in just a few steps in a commercial real estate building:
- Cut the trenches: The trenches are cut into the concrete, about 8 inches wide and 4 inches deep. The trenches are dug along the building’s interior perimeter. If the space already has raised access floors, this step is completely skipped, reducing installation time and cost.
- Place the trench heaters in the trenches: The trench heaters simply slide into the trenches along the building’s perimeter.
- Connect the trench heaters to the electric, hot water, or steam system: The trench heaters are connected to the electric or hot water or steam system using insulated pipes to prevent heat loss.
- Completing the aesthetic: With a seemingly endless catalog of options including color and pattern, designers can choose the grilles to match the building’s aesthetic.
Custom Options
The trench heating industry is rapidly growing as developers continue to see the advantages of the system. At AirFixture, we have the unique ability to customize our SoHo Trench Heaters to fit the exact needs of your space. Working directly with project architects and engineers, we develop trench heaters of all sizes and manufacture our products in-house to ensure they are made to exact specifications. Our trench heaters can be installed in many different configurations. From traditional raised access flooring and specially dug trenches to ceiling suspended and recessed in-wall installation, trench heaters can be discretely installed in any space. We apply the same custom options to our grilles. Fitting any curves, corners and odd measurements in any of our many color options, our custom trench heating solutions make installation easy.
Assessing trench heating capabilities
The many advantages of trench heating make it an enticing option as an alternative to traditional overhead HVAC systems, but not every building is equipped to accommodate a new heating system. You may be asking yourself, “is my building a good fit for trench heating?” We've put together a short list of key indicators that your building might be a good fit for converting to trench heating.
- Building size: Trench heating is cost effective for all building types and sizes but is especially effective for large open areas and space with glass walling.
- Building layout: AirFixture’s trench heating options are not one-size-fits-all and we offer custom sizes and dimensions. We work directly with the client and partner architects and engineers to design trench heating systems for unique buildings.
- Flooring: Trench heating can be installed in all floor types and is easily adaptable to raised access flooring. Trench heaters easily integrate with existing flooring, regardless of material.
- Climate: Trench heating is a good option for buildings in any climate.
- Your current heating system: If your current heating system is inefficient or outdated, trench heating is an easy way to improve efficiency and comfort.
If your current overhead heating system just isn’t cutting it, it might be time to consider your alternatives. Trench heating is a cost-effective, long-term solution for your commercial building’s unique needs. At AirFixture we offer decades of experience providing direct client collaboration to create a custom trench heating solution. If you are interested in converting your commercial building to trench heating, contact us today to learn more.