Questions & Answers

Radiation is one of the three ways heat propagates. To give a practical example, if we move from a shaded area to a sunny one, we immediately feel a greater sensation of heat, even though the air temperature remains unchanged. This is because the sensation of heat comes from direct exposure to solar rays and not from the air temperature. This natural propagation of heat is called radiation.

Radiation is electromagnetic energy in the infrared range which, unlike conduction and convection, has the advantage of propagating through a vacuum; this energy, instead of being absorbed by the air, is absorbed by the surface of solid bodies. This means there is no energy loss into the environment.

Radiant heat directly affects solid bodies and does not waste energy in the air. Below is a quick comparison between a hot air heating system and a radiant system in environments with medium and high ceilings.

We have a wide range of products that, depending on the required technical solutions, produce radiation using various energy sources: methane gas and LPG (G20, G25, G30, G31), diesel, hot water, superheated water, steam, and electricity.

The main elements to take into consideration are:

  • The type of fuel or energy source potentially available for the radiant system (gas, water, electricity, etc.);
  • The total area to be heated and whether zone heating is required;
  • The height at which the radiant system can be installed;
  • The amount of air exchange present in the environment;
  • The degree of insulation of the building;
  • Required internal comfort temperature and average external temperature during the cold season.

Based on these main data points and other elements to be verified case by case, our technical offices will develop a tailor-made project, identifying the most suitable solution for specific needs.

Depending on the type of system, there are different minimum and maximum installation heights. Generally speaking, with our radiant systems, we can implement installations with heights from 2.5 m up to over 35 m.

Advantages of radiant ceilings with copper piping and aluminum diffusers compared to the now outdated technology using small-diameter plastic capillary tubes:

  • The quality, reliability, and durability of the exchanger consisting of a copper tube (usually Ø 12 mm) with an aluminum diffuser are objectively superior compared to the plastic capillary tubes (polyethylene or polybutylene) with an internal Ø of 4 to max 6 mm used in other systems. The radiant circuits can operate at pressures up to 5 bar.
  • Activation yield with Ø 12 copper tubes and aluminum diffusers is normally 40-50% higher than panels with Ø 8 or Ø 10 mm PE or PB tubes; therefore, the thermal units operate at a lower temperature in cooling and a higher temperature in heating, with better efficiency and consequent savings on management costs that can reach up to 30%. Alternatively, the % of active ceiling surface with copper tubes can be reduced compared to plastic tubes for the same thermal performance, with considerable economic advantages on the price of the radiant ceiling.
  • Activation yield with Ø 12 copper tubes and aluminum diffusers is normally 40-50% higher than panels with Ø 8 or Ø 10 mm plastic tubes; therefore, the refrigeration machines operate at a higher temperature, with better efficiency and consequent savings on management costs of 30%. Alternatively, the % of active ceiling surface with copper tubes can be reduced compared to plastic tubes for the same thermal performance, with considerable economic advantages on the price of the radiant ceiling.
  • Speed of assembly: assembly times are normally 50% lower compared to plasterboard panels with plastic capillary tubes.
  • By using Ø 12 mm copper tubes, longer circuits can be created compared to circuits with Ø 8 or Ø 10 mm capillary tubes, resulting in the simplification of hydraulic circuits: for a typical room, a solenoid valve with one flow and one return is sufficient, whereas capillary tube panels require multi-way manifolds (3/4/5 way flow/return) with consequent higher costs due to: more distribution piping, more water junction points, and more labor for installation.
  • Zero maintenance: in ceilings with copper piping, chemical treatments of the fluid are not necessary. Conversely, it is mandatory for panels with plastic tubes; chemical treatment with polyamines or oxygen inhibitor additives must be constantly monitored over time with specific instruments to verify that the additive percentage complies with the manufacturer’s instructions. With every addition of thermal fluid, the additive (always of the same type and company) must be integrated because at very low concentrations it can become corrosive, or if too high, it can crystallize. As with antifreeze additives, it will also be necessary to drain and refill the thermal fluid over time. These operations require specialized labor with very high management costs.
  • In the PLAFORAD ceiling, it is possible to fully recover the active modules if modifications and/or renovations of the false ceiling become necessary.
  • Lower pressure drops of the carrier fluid (water) circulating inside the copper tubes (12 mm diameter versus 6 mm diameter of the plastic tubes) and consequent significant energy savings. An electricity consumption saving of 60% is estimated.
  • Greater rigidity and resistance to stress; with adequate hanging, a false ceiling with anti-seismic performance can be easily created.

For over a year, the Q-RAD Consortium has been working on a draft standard for the qualification of radiant system installers. This is a quality mark aimed at certifying the professionalism of installation technicians and guaranteeing reliability to the end customer. The draft standard provides for two levels of training: installer and supervisor. With this survey, the Q-RAD Consortium, which brings together the main Italian companies in the radiant sector, asks its audience to express their opinion on the choice of logo to be attached to the qualification certificate.
This refers to the “Finanziaria 2017” portal for interventions completed in 2017.
If interested, send an email to mk@fraccaro.it

You can find information regarding environmental labeling of packaging at the following link: Environmental Labeling

There is no single answer to this question, and there are several aspects to take into consideration.

A warehouse is not like a home; it has different needs to ensure internal comfort. An industrial warehouse often has a considerable height, extraction systems are present, and doors are opened repeatedly to move material. An industrial warehouse is often used for 8 hours a day, 5 days a week. Given these premises, the best solution for heating an industrial warehouse is the use of radiant strips.

For the same size of the environment to be heated, heating with radiant strips will have lower consumption compared to heating with hot air because the heat is distributed more efficiently. Hot air inside the warehouse tends to rise, creating heat stratification; to reach the comfort temperature at the level of the people, the temperature will be much higher in the upper part of the warehouse. Furthermore, radiant strips allow for zone heating, thus heating only the occupied areas, whereas with hot air, it will always be necessary to heat the entire warehouse. Radiant strips also have a very fast response time from when they are turned on to when the heat is felt, so it is enough to program them to turn on just a few minutes before the start of the shift.

In warehouses where high-flow extraction systems are present, it is preferable to use a radiant heating system.

Radiant strips, by heating through radiation, “suffer” less from the effect of extraction systems. Similarly, in environments where doors are opened repeatedly, the use of radiant strips limits the dispersion that would otherwise be created using a hot air heating system.

That is only partially true.

Hot air goes upwards because it is lighter than cold air, which creates convective currents.

With radiant strips, however, we do not heat the air; we heat through radiation.

Radiation naturally moves from a warmer surface toward a colder surface; in this case, the surface of the radiant strips is very hot, and therefore the heat will go toward the colder area, so

The heat from the radiant strips does not go upwards because they are enclosed within an insulated shell that limits heat dispersion toward the unused parts of the warehouse.

Furthermore, our strips undergo a special treatment that makes them red on the exposed part; the red color, in addition to making them more visually appealing, allows the strip to radiate heat better; the upper part of the strip, on the other hand, is not treated specifically to limit upward radiation.

Radiant strips consist of a burner module and the radiant strips themselves.

The burner, powered by gas or another fuel, is installed outside the warehouse (on the wall or roof); in this way, the combustion and the gas remain outside the warehouse.

Inside the burner module, we find the burner, where gas combustion occurs on the flow side, and an extractor on the return side.

Inside the warehouse are the radiant strips, which are the heat distribution terminals.

Radiant strips are essentially a spiraled tube—which is why they are called strips—inside which the carrier fluid, namely the gas combustion, flows. The combustion gases circulate thanks to the vacuum created by the fan located inside the burner module.

The radiant strips are then positioned inside a module which serves both to reduce upward convective dispersion and as a support for hanging the strip from the ceiling.

There is no maximum height for the installation of radiant strips.

There is a minimum installation height required by current regulations, which stipulates that there must be at least 4 meters from the floor to the surface of the radiant strip.

From 4 meters upwards, it is possible to install radiant strips. The higher the warehouse, the greater the advantages of using radiant strips compared to using hot air.

The mandatory minimum distance that must exist between the walking surface (the floor) and the lower edge of the appliance’s radiant circuit is 4 meters.

The main regulatory reference is the Ministerial Decree of April 28, 2005 (which updated the previous Ministerial Decree of July 23, 2001).

Radiant strips can be powered by methane gas, liquid propane gas (LPG), diesel, biomethane, or hydrogen mixtures.

Radiant strips can be applied in many types of industrial environments and beyond.

In some cases, however, radiant strips cannot be installed due to fire prevention regulations.

In that case, if we want to keep radiation as the heating method, we can propose a solution with water or steam radiant panels.

Radiant panels are metal panels for heating large environments and consist of steel tubes: inside which hot water or steam flows.

Radiant plate: A sheet metal that wraps around the tubes and heats up by contact, then transmitting the heat downwards by radiation.

Upper insulation: A rock wool mat placed above the tubes to prevent heat from dispersing toward the roof instead of toward the people.

If you are thinking of a padel court, a bowling green, a gym, or any type of indoor court.

Radiant strips are the excellent solution for heating environments like gyms; the advantages that make radiant strips the optimal solution for industrial environments also make them excellent for sports use.

The absence of air movement maintains a comfortable environment even for athletes without moving dust or making noise.

Furthermore, thanks to their response speed and the possibility of zone heating, radiant strips allow for the optimization of heating use by heating the courts only when they are occupied.

No, radiant strips are an excellent solution for heating but they cannot provide cooling.

For cooling, there are other equally efficient solutions: hybrid radiant strips or by combining radiant strips with evaporative coolers.

Hybrid radiant strips are the hybrid evolution of radiant strips to meet legal obligations on renewables without sacrificing the comfort and advantages of the radiant system.

A hybrid system is not a single piece of machinery, but a factory-made system of three components working together:

The Gas Radiant Strip: A circuit of steel tubes suspended from the ceiling that burn gas and heat by radiation (like the sun).

The Heat Pump (Air-to-Air): An external unit that exploits the thermal energy of the air and transforms it into heat using electricity, possibly produced by the photovoltaic system.

Intelligent Control Unit: The “conductor” of the system that coordinates in real time which of the two sources to use based on the external temperature and the desired internal temperature.

During harsh winters when the external temperature drops below 7°C, the heat pump loses efficiency. In this phase, the gas radiant strip intervenes, ensuring immediate heating of the warehouse.

In mid-seasons when the external temperature is not too harsh, the heat pump works at maximum efficiency. The system introduces hot air into the warehouse via dedicated terminals. If the temperature is not enough, the gas strip intervenes only to provide a quick “boost.”

In summer, the heat pump enters cooling mode; this is the great advantage compared to traditional strips. The heat pump reverses the cycle and introduces fresh, dehumidified air, making the warehouse comfortable even in July and August.

The use of methane is a sustainable choice, particularly if it involves replacing an old hot air heating system.

Radiant strips, thanks to their heating efficiency, represent an excellent decarbonization solution, reducing fuel consumption; in addition to a reduction in the bill, emissions into the atmosphere are also reduced.

You will certainly be happy with your choice.

A radiant strip system compared to a hot air system allows for a reduction in consumption of at least 20%; the higher the warehouse, the greater the reduction in consumption.

Furthermore, the radiant strip gives you the choice of where and whether to heat; if there are warehouse areas or areas not occupied by operators in the warehouse, you can easily decide not to heat that zone.

Radiant systems vs traditional systems

Comparison of environment conditioning solutions

Girad system vs convection heating system

Industrial heating with Girad condensing radiant strips

  • Immediate heating and absence of convective currents
  • No upward stratification
  • Excellent environmental comfort across the entire heated surface
  • Heats only where needed
  • Guaranteed energy savings
Girad

Industrial heating with traditional hot air or underfloor systems

  • Continuous movement of large quantities of air masses with consequent suspension of dust and unhealthy premises
  • Upward stratification with poor system efficiency
    and high management costs
  • Waste of energy

Plaforad system vs traditional heating system

Plaforad radiant ceiling cooling

Plaforad radiant ceiling heating

  • The best thermal comfort
  • Great energy savings thanks to water temperatures
    of 30-35°C in heating and 15-18°C in cooling
  • No upward stratification
  • Reduced air exchange, no annoying drafts
  • Use of renewable energy
  • No maintenance
Plaforad

Cooling with traditional systems

Heating with traditional systems

  • Upward stratification with poor system efficiency
  • High management costs
  • Waste of energy