Trench heating systems normally deliver warm air by using ventilation ducts that are mounted on ceilings. However, this is not very efficient, since warm air rises above cold air by natural convection. As a result, a conventional HVAC system needs additional fan power to achieve effective heating for the lower portion of indoor spaces. 

Trench heating is an innovative solution, which eliminates some limitations of conventional heating systems thanks to a floor installation:

• Heat is delivered from trenches in the floor instead of ceiling-mounted ducts, taking advantage of the natural movement of air. Since warm air rises by itself, it is distributed effectively through indoor spaces, saving fan power in the process.
• On the other hand, natural convection represents an obstacle when warm air is being delivered from above. 
• The natural movement of warm air also improves comfort, compared with traditional HVAC systems that force warm air downwards with fans.

This heating method also offers aesthetic advantages and design flexibility. Since there are no radiators mounted on walls, architects and interior designers can forget about their visual impact. In particular, this is an advantage in modern designs that use windows going from the floor to the ceiling. Since the heating element is embedded in the floor, the only visible part is a grille, which can match the colors of the floor and surrounding elements.

How Does Trench Heating Work?

The basic principle of trench heating is taking advantage of natural convection: since warm air rises by itself, it makes sense to release it from the lower portion of a room. However, these systems can also include a fan to increase air circulation when needed.

• The MDL Verano Trench Heater delivers space heating by using only natural convection, and this saves the electricity consumption associated with fans.
• The MDL Verano Trench Fan Coil is an example of a fan-assisted product. The fan uses an electronically commutated motor or ECM, which adjusts speed from 0% to 100% as needed. An ECM can achieve electricity savings up to 75% compared with a conventional single-speed fan motor.
• Both heating systems have the option of wooden, aluminum or stainless steel grilles, offering flexibility for different types of architecture or interior design concepts. 

With the increasing popularity of curtain walls in modern architecture, MDL Solutions developed the MDL Verano Façade Convector. This heater has a housing that attaches to the mullions of curtain walls, simplifying its installation. Like the trench fan coil, this is a fan-assisted product that uses an EC motor for energy efficiency.

Advantages of Trench Heaters: Energy Efficiency

Trench heating delivers warm air more effectively, since it is released at floor level and distributed mostly by natural convection. Conventional space heaters cannot deliver warm air with the same effectiveness, requiring fan power and additional hot water circulation. To meet the heating needs of a given indoor space, a trench heater consumes less energy.

Trench fan coils come with motors and fans, which means they can increase air circulation for additional heating. However, they can also operate with only natural convection. On the other hand, a ceiling-mounted heating system must use the fan permanently, or otherwise the warm air will simply accumulate near the ceiling, while the lower portion of the room gets cold.

Advantages of Trench Heaters: Comfort and Indoor Air Quality

By eliminating dependence on forced air movement, trench heating improves indoor air quality and comfort.  When conventional HVAC systems use fans to force warm air downwards, there is a negative impact on comfort. The airflow required for effective heating can cause turbulence and air drafts, and there may also be cold spots because warm air is not distributed evenly.

Indoor air turbulence and drafts also have a negative impact on health, since they can spread particles like dust and mold spores. In particular, individuals who suffer from allergies or asthma are very susceptible to a drafty indoor environment.

Since trench heaters do not depend on fans, they can operate silently. On the other hand, a ceiling-mounted system can be very noisy on a cold winter day, since fans must run at full power to blow a large volume of warm air downwards. This noise can cause discomfort, and also distraction in business settings.

MDL Solutions offers trench heaters in both configurations, using only natural convection or assisted by high-efficiency ECM fans. Contact us to know more about the heating options for your building, and save energy while improving comfort.