1. Introduction to heat Is this heat? When I touch it, it burns me. I can feel the heat at a distance The hot gases rise

2. But is this heat? Yes The difference between the two is Temperature Any substance whose temperature is above -276 degrees celsuis or -460 degrees Fahrenheit contains heat

3. Whether something is hot or cold is subject to your preconceived experience When we see blue we tend to think cold When we see red we tend to think hot

4. HVAC and R H is for heating V is for ventilation AC is for air conditioning or cooling R is for refrigeration

5. Heating Increasing temperature from an intensity that is felt as too low to a comfortable intensity This can be accomplished by combustion of a chemical that releases heat Moving of heat from one place to another Convincing the person that they are actually warm

6. Ventilation The movement of air to distribute heat

7. Air Conditioning This is a little more complicated Air conditioned air is generally considered cooled air. Its humidity is also changed when it is cooled so it is considered conditioned

8. Refrigeration Refrigeration is generally considered as temperatures below human comfort First used to extend perishable food life

9. Heating Technology Technologically, heating is far easier than cooling The first forms were wood fired campfires around which everyone sat to be warmed

10. Advantages Easy to start if you had something hot and it had not rained lately Fuel was easy to find Fire looks cool

11. Disadvantages Was not self sustaining Smoke always followed you wherever you sat Rain had a dampening effect You were always cold on the side opposite the fire

12. Ways to make campfire better Place fire in some sort of shelter to contain heat

13. A better system with fire in center and way for smoke to leave

14. An even better way

15. But how effective is a fireplace?

16. Can you effectively heat a structure with a fireplace? No Any ideas why?

17. The fireplace draws air from the structure in large amounts

18. If you draw large amounts of air from a structure, it must be replaced by outside air

19. Where do you think the air comes from?

20. It must be drawn in from cracks in windows and doors

21. And what temperature is this air?

22. The same temperature as the outside air which is why the other rooms in the structure are very cold after the fire has been burning for a while

23. So what can be done to solve this problem?

24. The Franklin Stove

25. The Franklin Stove (invented by Ben Franklin) covered the majority of the open area that removed so much air and only allowed enough air to support combustion

26. The cast iron body of the stove was warmed by the fire which warmed the air in the room

28. We have developed a stove that is reasonably efficient that can heat a structure. Is this the best system for heating?

29. What if there are more than one room in the house? The temperature in the room with the stove will be warm All other rooms will be progressively cooler the farther they are from the heat source

30. This is a typical modern ductwork layout system

31. Heat travels from the furnace Forced by a fan through the Supply ducts to the Conditioned space Return air travels Through the return Ducts to the furnace