A block heater is used in cold climates to warm an engine prior to starting. They are mostly used for car engines; however, they have also been used in aircraft engines.
The most common design of block heater is an electrical heating element embedded in the engine block.
Pre-heating of an engine is primarily used to make it easier to start. Added benefits are:
Block heaters or coolant heaters are also found on the diesel engines in standby generators, to reduce the time taken for the generator to reach full power output in an emergency.
The vehicle operator must have access to electrical power. In cold climates, parking areas for residents, employees, or students, or paid public parking areas, may have electrical outlets.
The operator must disconnect the power cord before driving away. Forgetting to disconnect can result in damage to the power cord or the vehicle. After a snow storm, the cable may not be visible under the snow. Residential overnight street parking may not allow an extension cord to cross a public sidewalk.
The energy used to heat the engine adds a cost. However, the savings in fuel generally outweigh this cost, especially if a timer is used to limit the heating period to about 4 hours before the expected start time. Taking the needed precautions, a kerosene jet-heater can also be used to pre-heat the engine. [2]
Some cars are produced with block heaters from the factory, while others are fitted with block heaters as an aftermarket add-on. [3] The most common type of block heater is an electric heating element in the engine block, which is connected through a power cord often routed through the vehicle's grille. Some block heaters are designed to replace one of the engine's core plugs and therefore heat the engine via the coolant. [4]
Alternative methods of warming an engine include: [5]
Electric timers are often used with engine warmers, since it is only necessary to run the warmer for a few hours before starting the engine. [1] Some cars pump hot coolant from the cooling system into a 3-litre insulated thermos-style reservoir at shutdown, where it stays warm for several days. [6] While idling is commonly believed to warm an engine, for most it is not effective. [7]
Block heaters are frequently used in regions with cold winters such as the northern United States, Canada, Russia and Scandinavia. In some countries where block heaters are commonly used, carparks are sometimes fitted with electrical outlets for powering the block heaters.
Testing in the 1970s of warm-up times for block heaters found little benefit in operating a block heater for more than four hours prior to starting a vehicle. [8] It was found that coolant temperature increased by almost 20 °C (36 °F) during the first four hours, regardless of the initial temperature. Four tests were run at ambient temperatures ranging from −29 to −11 °C (−20 to 12 °F); continued use of the heater for up to two hours more only further increased the temperature by up to 3 °C (5 °F). Engine oil temperature was found to increase over these periods by just 5 °C (9 °F). [9]
An early example of pre-heating piston engines prior to start-up was in the 1930s in Northern Canada, where aviators flew with flight engineers who were responsible for preparing the radial engines for shutdown and startup to reduce the effects of subzero temperatures. The flight engineer was responsible for draining the oil into buckets at night, and preheating the engine and buckets of oil using a blanket wrapped around the engine and a device known as a blow pot – essentially a kerosene jet-heater used for several hours prior to flight. [10]
During World War II, German pilots could not stop the oil freezing in the engines of their Messerschmitt Bf 109 planes because of the extreme cold first experienced in the 1941 winter campaign in the Soviet Union. A captured Soviet airman showed them how pouring aviation fuel into the aircraft's oil sump would thaw the oil. Another solution, also learned from the Soviets, was to ignite fuel in the space around the engine. [11]
An early automotive use was the "head bolt heater", invented by Andrew Freeman in the United States and patented on 8 November 1949. [1] [12] [13] These early heaters replaced one of the engine's head bolts with a hollow, threaded shank containing a resistive heating element. [13] [14] Before the block heater was introduced, people used a variety of methods to warm engines before starting them, such as pouring hot water on the engine block or draining the engine's oil for storage inside overnight. Some even shoveled embers underneath their vehicle's engine to obtain the same effect. [12]
A thermostat is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint.
Internal combustion engine cooling uses either air or liquid to remove the waste heat from an internal combustion engine. For small or special purpose engines, cooling using air from the atmosphere makes for a lightweight and relatively simple system. Watercraft can use water directly from the surrounding environment to cool their engines. For water-cooled engines on aircraft and surface vehicles, waste heat is transferred from a closed loop of water pumped through the engine to the surrounding atmosphere by a radiator.
A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning systems, which can both cool and warm interior spaces.
A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.
Electric heating is a process in which electrical energy is converted directly to heat energy. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electrical device that converts an electric current into heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy. Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators.
Vegetable oil can be used as an alternative fuel in diesel engines and in heating oil burners. When vegetable oil is used directly as a fuel, in either modified or unmodified equipment, it is referred to as straight vegetable oil (SVO) or pure plant oil (PPO). Conventional diesel engines can be modified to help ensure that the viscosity of the vegetable oil is low enough to allow proper atomization of the fuel. This prevents incomplete combustion, which would damage the engine by causing a build-up of carbon. Straight vegetable oil can also be blended with conventional diesel or processed into biodiesel, HVO or bioliquids for use under a wider range of conditions.
A fan heater, also called a blow heater, is a heater that works by using a fan to pass air over a heat source. This heats up the air, which then leaves the heater, warming up the surrounding room. They can heat an enclosed space such as a room faster than a heater without a fan, but like any fan, create a degree of noise.
Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility than the original energy source. Sources of waste heat include all manner of human activities, natural systems, and all organisms, for example, incandescent light bulbs get hot, a refrigerator warms the room air, a building gets hot during peak hours, an internal combustion engine generates high-temperature exhaust gases, and electronic components get warm when in operation.
A heater core is a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine is passed through a winding tube of the core, a heat exchanger between coolant and cabin air. Fins attached to the core tubes serve to increase surface area for heat transfer to air that is forced past them by a fan, thereby heating the passenger compartment.
The wax thermostatic element was invented in 1934 by Sergius Vernet (1899–1968). Its principal application is in automotive thermostats used in the engine cooling system. The first applications in the plumbing and heating industries were in Sweden (1970) and in Switzerland (1971).
An oil heater, also known as an oil-filled heater, oil-filled radiator, or column heater, is a common form of convection heater used in domestic heating. Although filled with oil, it is electrically heated and does not involve burning any oil fuel; the oil is used as a heat reservoir (buffer).
Idle reduction describes technologies and practices that minimize the amount of time drivers idle their engines. Avoiding idling time has a multitude of benefits including: savings in fuel and maintenance costs, extending vehicle life, and reducing damaging emissions. An idling engine consumes only enough power to keep itself and its accessories running, therefore, producing no usable power to the drive train.
In a diesel engine, a glow plug is a heating device used to aid starting of the engine in cold weather. This device is a pencil-shaped piece of metal with an electric heating element at the tip.
Trionic T5.5 is an engine management system in the Saab Trionic range. It controls ignition, fuel injection and turbo boost pressure. The system was introduced in the 1993 Saab 9000 2.3 Turbo with B234L and B234R engine.
A gasoline heater is a small gasoline-fueled space-heater. Fixed versions were originally used mainly for supplemental heat for passenger compartments of automobiles and aircraft, with the latter still in production. Portable versions were also made.
Radiators are heat exchangers used for cooling internal combustion engines, mainly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plants or any similar use of such an engine.
A liquid nitrogen engine is powered by liquid nitrogen, which is stored in a tank. Traditional nitrogen engine designs work by heating the liquid nitrogen in a heat exchanger, extracting heat from the ambient air and using the resulting pressurized gas to operate a piston or rotary motor. Vehicles propelled by liquid nitrogen have been demonstrated, but are not used commercially. One such vehicle, Liquid Air, was demonstrated in 1902.
A truckmount carpet cleaner is a carpet and upholstery cleaning unit that is generally mounted to the floor of a van or trailer. Its cleaning method is hot water extraction. The operator would park the van near the premises, connect the vacuum hose and solution line hose into the machine, bring the hoses into the building, and connect a carpet cleaning wand to the end of the hoses.
A cold start is an attempt to start a vehicle's engine when ambient temperatures are much lower than its normal operating temperature. A cold start can be difficult for an engine due to higher viscosity of oil and fuel in cold temperatures.
An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine, the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine. The force is typically applied to pistons, turbine blades, a rotor, or a nozzle. This force moves the component over a distance. This process transforms chemical energy into kinetic energy which is used to propel, move or power whatever the engine is attached to.
