HEATING SYSTEM TECHNOLOGY&

HEAT LOSS/INSULATION

Mr. Ilko

IN OUR LIVES

We require many different heating technologies to make sure our lives stay warm and cozy

Some of the first were blankets, coats, hats, etc

Now we rely on our machines to provide an even more comfortable environment (i.e furnace)

HOW WE STAY WARM

All rooms do not have furnaces inside them to heat the rooms so we need to have a way to move heat around

We also need ways that will prevent our furnaces from turning on when we don’t need them, but turn on during chilly days

(i.e Summer time)

THERMOSTATS

The most common way we can control the heat in our house is through a device called a thermostats

Room temperature or 20○C is the most common setting for us in our houses, offices or schools.

Thermostats control the level of the heat in the building its set up in Thermostat means “thermo” –heat, “stat” – means

to keep stable

THERMOSTAT CONT…

We don’t only use thermostats to maintain temperature of the rooms in a building They are also used to adjust the

temperature of certain electrical devices ( oven or air conditioner)

HOW IT WORKS?

Inside of a thermostat the is a bimetallic strip that consists of two different metals

When heated one of the metals will expand faster than the other. This causes the strip to bend

The bending of the bimetallic strip is used to measure the temperature change

As the strip bends and unbends it opens and closes electrical circuits that also control the heat-regulation devices

HEATING SYSTEMS

There are two main types of systems: Local heating system Central heating system

Both contribute in different ways and both have their own disadvantages

LOCAL HEATING SYSTEM

Provides heat for only one room or a small part of a building

Common examples of this type of heating system are; Fireplaces Wood-burning stoves Portable space heaters

CENTRAL HEATING SYSTEM

Provides heat from a single, central source (furnace)

Heat transfers through a network of pipes, ducts, vents or other openings throughout the building

Most of the newer homes have forced air heating, the older ones have hot water heating

DEFINITIONS

Find the following definitions at the back of your book Forced air heating-

Hot-water heating-

IN ORDER FOR ALL THIS TO WORK THE PROCESS OF CONVECTION WORKS CONSTANTLY

It moves all of the warm air around the room keeping the temperature warm

KEEPING COOL

Similar to producing heat in we also try to keep cold in, in certain situations (freezer)

We commonly use cooling systems to remove heat from a room or other enclosed space. The basic parts are; a storage tank, a compressor, a

freezer unit, condenser coils and a refrigerant.

The refrigerant (liquid) used in a refrigerator evaporates at a very low temperature. This creates freezing temperatures inside the fridge

INSULATION

Used to limit heat loss to the outside environment or to limit the amount of heat that is able to enter a cooler building on a hot day

Because heat only travels one direction (high to low), insulation is good for both cases.

MATERIALS IN BUILDING

When you are building a home you want to pick things that will be good insulators not conductors

You don’t want materials that will allow easy transfer of heat in and out of the house to easily

The thermal conductivity of a material reflects its ability to transfer heat by conduction. Eg. Bricks, fiber glass, Styrofoam, stone, etc

HEAT LOSS

Contractors commonly use infrared photography to check for areas of heat loss in a building. Its called the thermogram

Colour represents the type of heat loss The roof, windows, doors and walls are the main

problem areas

The problem with this is that we need more heat to compensate for this, so we create more waste to keep warm.

R-VALUE

Every insulator is given a number called an R-Value

The higher the R-Value, the better the product is at providing insulation.