There is still enough heat in the air to run your heat pump when the temp is in the 30,s
Usually, you will notice diminished heating capacity from your system, and the out side temperature is dropping below the average temperature your heat-pump operates at. This is the time to activate your emergency heat.
"em heat" stands for emergency heat, when the temperature drops below a certain point this will allow your heat strips to kick in, you can also switch at any time to emergency heat and the heat strips will kick in, this however, allows the system to run like you have an electric heat/cool unit vs. a heat pump. The heat pump mode is more efficient but emergency heat will produce warmer air quicker. Hope this answers your question.
A heat engine can never be 100% efficient due to the second law of thermodynamics, which states that some heat energy will always be lost to the surroundings. The temperature required for maximum efficiency is the temperature of the heat source for the engine. The efficiency of a heat engine is determined by the temperature difference between the heat source and the environment.
An emergency blanket works by reflecting a person's body heat back towards them, helping to retain warmth and regulate body temperature in emergency situations.
The most efficient temperature for heat regulation in a heating system is typically around 68-72 degrees Fahrenheit. This range allows for comfortable heating while also being energy-efficient.
It is generally more efficient to keep the heat on at a consistent temperature rather than turning it off and on frequently. This helps maintain a stable temperature in your home and can reduce energy consumption.
It is usually not energy that is efficient or inefficient. Rather, the technology used to extract it may be efficient or inefficient. In the case of any heat energy, the upper limit to the efficiency is given by the Carnot equation for heat engines, and depends on the temperature of the heat source, as well as the environmental temperature.
Emergency blankets work by reflecting and trapping a person's body heat back towards them, preventing heat loss and helping to maintain their body temperature in emergency situations.
In order for a heat engine to be 100 percent efficient, the temperature of the cold reservoir where waste heat is transferred should be absolute zero (0 Kelvin). This is not achievable in practice, as it violates the second law of thermodynamics.
Even if the friction were totally eliminated, a heat engine still could not convert heat completely into work and be 100 percent efficient. Instead, the efficiency of an internal combustion engine depends on the difference in the temperature of the burning gases in the cylinder and the temperature of the burning gases in the cylinder and the temperature of the air outside the engine.
They create heat inside the object being cooked, instead of wasting it outside.
An emergency blanket (or thermal blanket) is used in emergency situations to keep a person warm by radiating their body heat back to them, and minimizing temperature loss to the environment.