Unit c - section 3.2-3.3 -- heating system technology
- 1. HEATING SYSTEM TECHNOLOGY & HEAT LOSS/INSULATION Mr. Ilko
- 2. 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)
- 4. 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)
- 5. 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
- 6. 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)
- 8. 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
- 10. HEATING SYSTEMS There are two main types of systems: Localheating system Central heating system Both contribute in different ways and both have their own disadvantages
- 11. 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
- 13. 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
- 15. DEFINITIONS Find the following definitions at the back of your book Forced air heating- Hot-water heating-
- 16. 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
- 17. 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
- 19. 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.
- 20. 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
- 22. 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.
- 24. 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.