Block heater

Heaters are used to heat the passenger compartment of vehicles of all types, without relying on the heat output of the running engine. They are generally operated directly from the tank to the fuel of the respective vehicle and can either heat the air of the interior or be integrated through the cooling water circuit of the vehicle in the heating circuit.

Manufacturer of fuel-operated heaters, for example, Eberspacher, Webasto or Truma.

In addition, the heating can also be electrically; This works due to the system, where a network connection ( an outlet ) is provided.

Manufacturer of electric heaters are eg Calix, Defa or knight.

• 2.1 timer
• 2.2 Remote Control 2.2.1 GSM Remote Controls
• 2.2.2 Radio Remote Control

Technology

A parking heater works like a boiler in a residential home heating. In a burner fuel is burned; exhaust their heat through the vessel wall into the surrounding medium (water or air). The operation of an oil burner can not be transferred to a heater, as this, a high pressure pump for the fuel would be necessary. The combustion air blower blows the air tangentially into the combustion chamber. This creates a vortex of air is formed similar to a tornado. A small part of the air is branched off into a secondary chamber. This is a space surrounded by metal gauze glow plug.

The chamber is preheated via the glow plug, controlled the fan at minimum. As soon as the temperature of the chamber is sufficient, fuel is pumped. This ignites and the flame passes through a channel in the actual combustion chamber ( in the main air stream ). Once the flame has stabilized ( the combustion chamber is hot enough ), the glow plug is turned off. The fuel is then evaporated in the auxiliary chamber and enters gas into the combustion chamber where it ignites (see a jet engine combustion chamber ). This construction has the advantage of not requiring any high-pressure pump for the atomization of the fuel, as is necessary for example in oil burners. The disadvantage is that the metal gauze ( "Burner fleece " ) is susceptible to contamination by residues in the fuel. Especially diesel heaters can easily coke. The continuously burning flame allows an almost ideal combustion with very low emissions. As with heating burners and the combustion generated similar to a jet engine, a relatively loud noise. Heaters are therefore usually at silencers, which should be used.

Until temperatures down to -40 ° C, the burner starts fine; after about 30 seconds it delivers its full power 4-6 kW, with even bus heaters up to 35 kW in the cooling water ( or - depending on model - 2.5 to 5 kilowatts directly into the air of the interior).

The fuel required for combustion is promoted to a first variant of a separate, be incorporated fuel pump to the heater. The disadvantage of this possibility was that this fuel pump has often troublesome. Therefore, a second variant was developed that incorporates the heater directly into the return line of the fuel circuit of the vehicle. These heaters have a small private fuel storage tank; as an additional pump is dispensable. Vehicles that do not have a fuel return line, also the heater is in the lead (petrol or diesel line management) can integrate. If the auxiliary tank runs empty the heater is not (the engine does run again until after use; continuous operation is not possible).

Each heater satisfies various security requirements; Operational safety is always given. Models with its own fuel containers have the advantage that in case of any disturbance limited fuel is available (the device does not turn itself off when a fault occurs, the operation ends when the fuel supply is exhausted ).

Long service life may result from deposits from the fuel problems. Therefore, to heaters, even in the warm seasons are taken once a month for at least 20 minutes in operation. Diesel equipment must not be operated with biodiesel ( RME), because this leads to a lot of smoke. RME also leads in the long term to combustion chamber deposits ( coking); For this purpose, the content of 5 to 7% contained in the diesel sufficient. Newer models have modified combustion chambers, which should prevent this.

Electric heaters use different solutions. There are water heater that can be looped as a fuel-driven heater in the coolant circuit, and variants are in which, instead of the freeze plugs in the engine immersion heaters similar coils used. The latter system was combined with a fan heater in the interior. You saved thereby the otherwise necessary water pump and electrical wiring for the fan on the car heater. Quite often heaters are used only in the interior, as they require only small changes itself (socket, wiring) on the vehicle. Here, however, is not heated, the coolant circuit of the engine. These heaters are specifically designed for this purpose, fan heaters for household purposes have high outlet temperatures and creates a fire hazard.

Air heating

The air heater level based [LH ] is usually installed in the cabin interior and to heat directly the cabin air which is sucked in by a fan. The response is almost without delay, since the internal flame is not only have to heat a water circuit. Modern devices are very quiet and are preferably used to hold, for example, truck drivers' cabs in the state (overnight) at a comfortable temperature level.

To reduce the risk of the occupants, strives to maintain a strict separation of the combustion air and cabin air circulation.

Water heating

The water-based stand heater [ WH ] are more compact and can be mounted virtually anywhere in the engine compartment and under the vehicle. Therefore, their domain is the passenger car, the interior does not allow additional internals. The very compact design (see picture) also allows internals in the engine compartment or behind the bumper of subcompact and micro cars.

WH is the heat generated from the burner to the cooling water of the vehicle. A (additional) electric circulation pump ensures the distribution of heat even with the engine off. Also, the indoor fan is activated, everything works as usual in the heating mode. For devices with high power, the energy produced by the combustion is discharged only via wasserumflossene heat exchanger by design.

Compared to the LH result from the indirect heating via the heating water several disadvantages:

• The start-up or integration period after power is usually several minutes, especially when the engine is to be preheated.
• The efficiency decreases because the water cycle is most often poorly insulated.

These disadvantages can be avoided if the WH directly and exclusively supplies the heating heat exchanger without mitzuerwärmen the engine (so-called island circuit).

The WH has compared to LH but also some important advantages:

• A preheated engine starts in cold weather to lighter and more onerous because the already cold by the less powerful car battery considerably less.
• The preheated engine suffers the mechanically stressful cold start only over a shorter period, as it quickly passes after starting the engine to operating temperature.
• In comparison to the less cold start fuel is preheated by the engine requires, significantly reducing both pollutant emissions and cost.
• For short periods ( eg railway gate ) of the internal combustion engine can be switched off without the heating of the vehicle therefore exposes. The electric water pump provides for this case is simply stored in the residual engine heat to the vehicle heater.
• Depending on the model, the heaters are switched on ventilation operation, in order to bring the interior temperature of a vehicle parked in the sun in the vicinity of the outside temperature.

Operation

A parking heater can be selectively activated by a timer or a remote control. Newer models allow the interrogation of the temperature of the vehicle interior and the switching on and off the auxiliary heating system via mobile phone.

Timer

There are two types of control switches: In one type, the switch-on time of the heating is set on the other hand, the expected departure time.

In the former, so the driver must estimate how long the heater according to experience needed to bring the car to a comfortable temperature. At last the heater is determined by a temperature sensor, the estimated heating time and become self- sufficient activated before the scheduled departure moment.

Meanwhile, there are also remote- operated switches of the second kind (see below)

Radio remote control

With the remote control, there are two main types can be distinguished according to the used transmission equipment: GSM and conventional wireless technology.

GSM remote control

The cell phone remote control works normally via SMS. This has the disadvantage that an additional SIM card is installed in the associated module in the vehicle, which is connected itself with pre-paid cards with regular fees. The necessary SMS usually cost telephone charges. As an advantage, the principle unlimited coverage is to be considered: In principle, can be such a heater from anywhere in the world to enable.

Some manufacturers extend an existing mobile phone, making it possible to offer this function particularly inexpensive. In any case, care should be taken that it is not permitted within the EU and some other countries to use electric car accessories without approval, otherwise the approval of the vehicle is switched off ( see e-mark).

Sometimes there are also GSM remote controls for heaters that have a voice chip. The heating is called and lists the various options. However, is not answered by voice, but by the multi- frequency dialing the phone.

With an old kit ( stowed under the dashboard ), a simple phone and a prepaid card you can build with some electronics experience a GSM control himself. The ( radio ) to mute output ( active low ) to the handsfree must be connected to the immediate start contact the operator module of the heater ( also in most cases, active low ). So that each can be turned on or off for each call input the heater arise without further costs. Alternatively, the mobile lighting be used as a trigger signal. For example, if one of the LEDs, an optocoupler connected (possibly with series resistor), this can turn the mass signal when lighting the display by an incoming call, which can start the heater via operating module as in the variant with the speakerphone. In this solution, ( old phone, SIM card, charging cable, optical couplers ) also are no ongoing fees.

Wireless remote control

The commonly built alternative is a conventional remote control, depending on the geographical situation has ranges from about 300 to 500 meters. Under optimal conditions, a range of 1000 m is reached.

In the field of remote controls, there are two principles: with and without feedback.

Without feedback ( also unidirectional) means that is not displayed on the remote control if the radio command was received. This method is still the standard.

With feedback ( bidirectional) means that in the remote control in addition a receiver is integrated in the vehicle and a transmitter which confirms receipt of the message. Remote controls with feedback usually allow a time delay analogous to the settings on the timer. For new bi-directional remote part also a diagnosis of auxiliary heating is possible.