Negative Temperature Coefficent Of Resistance Heated Flooring

This α o is called temperature coefficient of resistance of that substance at 0 o c.

Negative temperature coefficent of resistance heated flooring.

Just as all materials have a certain specific resistance at 20 c they also change resistance according to temperature by certain amounts. Negative temperature coefficient of resistance means that as the temperature of a piece of wire or a strip of semiconducting material increases the electrical resistance of that material decreases. The temperature coefficient of resistance α o. The alpha α constant is known as the temperature coefficient of resistance and symbolizes the resistance change factor per degree of temperature change.

Traditional radiators need to be heated to a high temperature between 149 167 degrees fahrenheit 65 75 degrees celsius in order to heat up a room effectively whereas floor heating only needs to run at a temperature of 84 degrees fahrenheit 29 degrees celsius or less depending on the floor finish in order to warm the room thereby. A temperature coefficient describes the relative change of a physical property that is associated with a given change in temperature for a property r that changes when the temperature changes by dt the temperature coefficient α is defined by the following equation. In general conductors have a positive temperature coefficient whilst at high temperatures insulators have a negative temperature coefficient. In contrast radiant floor heating systems heat the entire floor which leads to an evenly heated room and for an even ambient temperature around a person s body.

Materials with a negative temperature coefficient have been used in floor heating since 1971. Negative temperature coefficient. The location of the vents determines which parts of the room will be warmer than others. The value of resistance at initial temperature the rise of temperature and.

Forced air heating systems use vents to distribute warm air throughout a room. Radiant heating may be either hydronic water fluid flowing through pipes or electric electric resistance heating elements. Here α has the dimension of an inverse temperature and can be expressed e g. The negative temperature coefficient avoids excessive local heating beneath carpets bean bag chairs mattresses etc which can damage wooden floors and may infrequently cause fires.

Depending on the amount of heat or cold a thermistor is exposed to determines the amount of resistance they will offer in a circuit. From the above equation it is clear that the change in electrical resistance of any substance due to temperature mainly depends upon three factors. End users may feel uncomfortable when coming in contact with floor surfaces that are too warm or too cool. In 1 k or k 1.

The temperature of the floor surface is the key to determining what level of comfort is necessary. When resistance falls with an increase in temperature the material is said to have a negative temperature coefficient.