Evolution of Vehicle Heaters
Postado por Adelle Webber em
German Engineered PTC Fan Heater
A PTC fan heater uses a PTC, positive temperature coefficient heating element to produce heat distributed by a built-in fan to transfer the heat generated to a targeted air space effectively. This is the state-of-the-art method for heating vehicle passenger compartments.
DBK USA distributes these German-manufactured devices for US, Canadian, and South American customers.
The positive temperature coefficient refers to the relationship between temperature and resistance of the PTC ceramic heating elements. Resistance of the element increases as the temperature increases. This relationship automatically regulates the amount of heat provided by the device.
These attributes help make the PTC heaters safer and more efficient than conventional resistive heating devices that require temperature sensing and control circuits to maintain temperatures.
PTC heating elements are readily available for manufactured heating devices. Ensure you have the highest quality PTC fan heaters by utilizing German-manufactured DBK Cirrus Series Devices designed for commercial use.
Before purchasing a heater, ensure it has a device or component UL listing or certification. These German-manufactured heaters from DBK USA have both CE and UL markings on the external surface of the device. These devices are recognized as components with the following markings.
The first internal combustion heater was patented in 1893
This was when automobiles were just becoming the preferred mode of transportation in the United States. Initially, automobiles weren’t enclosed, creating a need for very warm clothing to keep the driver and passengers warm during the winter. It was a while before auto manufacturers began enclosing the vehicles with doors, roofs, and windows for passenger comfort.
A decade or more before aftermarket products became available to capture the engine's heat and exhaust gases to be piped into the passenger compartments for warmth. These early products also piped in obnoxious fumes and odors.
In 1929 Ford introduced a built-in heater option and, by 1933, providing an integrated system for heating. This was the first system to capture heat from the engine’s coolant system. By 1937 systems allowed the driver to regulate the airflow and temperature of the system.
It wasn’t until the 1950s that standard heaters became commonplace in all vehicles. Until the past decade, waiting for the engine to warm up before heat was generated was a common annoyance in northern climates.
Around the same time, manufacturers began embedding electrical elements into the glass of vehicles for rapid defrosting of window fog and ice. This still didn’t solve the problem of passenger comfort while waiting for the engine coolant to warm up sufficiently.
You no longer need to wait for combustible engine heating.
An age-old dilemma is waiting for engine heat to warm the cab, cockpit, train car, or automobile interior during the winter. How often have you kept wearing coats and gloves waiting for the passenger department of your car or cab to heat?
Electric seats, steering wheels, and window heating elements help, but they can be expensive additions to many vehicles and impractical for others. Even a brand new (EV) electric vehicle needs a supplemental heating system.
One of the most often used, most reliable, and safe solutions for instant heating of vehicles is a 12/24 volt PTC fan heater. These powerful devices supply direct heat under the coldest conditions. Why a fan heater? It isn't enough to create heat. The heat has to get to the area of the vehicle needing the heat. The fan provides that transportation for the heated air.
How do these heaters create heat?
PTC heating elements create heat by current flowing through the resistive solid-state ceramic disk. The electrical current produces heat when there is resistance to current flow. Higher resistance to current produces more heat.
The typical resistive element lightbulb invented by Thomas Edison produces heat and light when the resistance of current flow through the element inside the vacuum of the glass bulb. The same phenomenon occurs when current flows through resistive wiring designed to produce heat.
The difference between resistive wiring and PTC ceramic heating elements is that there is no combustion, no need for a vacuum, and the heat generated won't cause a fire. Instead, the ceramic surface heats and the heat transfer material surrounding the elements transfer the heat to other surfaces.
In the case of a fan heater, an additional fan moves the heat away from the element faster and directs it to the specific area requiring heating.
Fast heating with PTC ceramic element?
PTC heating is fast heating because initially, there is a high inrush of current heating up the element and its components quickly. The high inrush current is due to lower resistance in the piece at low temperatures.
Once the temperature increases, the device's resistance also increases, decreasing the current flow through the device. Conventional resistive heaters have a fixed resistance and current, which requires a minimum warm-up time to reach maximum heating temperature.
Why use a fan with PTC heating elements?
A built-in fan effectively decreases the delivery time for the heat to reach to space to be heated. The air passing over through heat transfer fins pulls the heat from the fins into the moving air. The heated air stream moves to heat away from the heating elements into the adjoining space.
This process allows more heat to be generated from the relatively small ceramic disks and transferred to air or surfaces to be heated. The rate of heating decreases as the temperature increases.
The DBK Cirrus series of PTC fan heaters have a separate fan circuit for safety and efficiency. However, since the heating circuit current changes with the temperature and resistance of the PTC heating element, it isn't practical to vary the current through the fan motor similarly.
The separate fan circuit allows air circulation regardless of the temperature of the heating device.
PTC heaters can operate on DC or AC voltage and current and fan built into the heating devices. The fan and the PTC heating elements are isolated from the devices' voltage power. Finger guards are an option to protect fingers from contacting the fan propellers.
How many watts does a PTC fan heater produce?
PTC fan heaters have a high watt density output, meaning they put out a lot of heat for their size. The amount of watts you need depends on many factors. For example, how considerable is the compartment to be heated, and the distance from the heating element? Of course, there will be heat losses dependent on the insulation of the ductwork and the compartment.
It is best to consult with an experienced thermal engineer for recommendations—Call 1-864-607-9047 to speak with one of DBK's experts.
How are the PTC fan heaters connected?
PTC fan heaters should come prewired with a separate fan circuit. An independent fan circuit helps circulate air when the heating element isn't energized. An individual on/off switch for the fan and the heating element is required.
The heating element circuit needs to be sized for high inrush current in that when the solid-state ceramic disk is cold, its resistance is low, and the current will be at the max. See chart for typical max inrush current at connected voltages.
Both the heater and the fan can run on AC or DC voltages. Most combustible engine electrical systems use DC voltages, but new EV systems have AC voltages.
The 12/24 volt Cirrus units can be mounted with a DIN rail clip. Talk with our engineers about other mounting options.
A DBK USA thermal engineering specialist can answer any questions about your application for a PTC fan heater or shop directly online for PTC Fan Heaters.