Heat Transfer Facts You Should Know To Save Energy

We all know that water flows down hill. If youEnergy Saving Action Items
want water to move up hill you have to "doHeat flows into our homes when it is hotter
some work" to get it there. If you do not wantoutdoors, than indoors. We can slow it down by
water to flow down hill you have to "do someshielding and insulating our house. Shielding and
work" to stop it like building a dam. "Doing someinsulation is like building a dam to delay water
work" is like paying your energy bill because itfrom flowing down hill.
causes some discomfort.By shielding, I mean shade trees and radiant
The first thing you need to know is that heatbarriers like aluminum foil or special paint. Shielding
naturally flows from a hot area to a cold area.that either blocks the sun or reflects radiant
Heat moves in three waysenergy back where it was coming from stops the
One way heat moves is radiation. We all knowsun's rays from heating our houses. Solar window
that if we are exposed to direct solar radiationscreens act as partial sun blocks. Reflective
we can feel the heat from the sun flowingradiant barrier materials act like a mirror and
directly to us. The sun is very hot so the heatreflect or deflect radiant heat away from your
flows from the sun to the earth. Sunburn is thehouse. Reflective film on windows works this way.
result of solar radiation.We want the solar radiation to hit our houses
The second method of heat movement is calledwhen it is cold outside in the winter. Planting trees
conduction. Conduction describes heat movingthat give summer shade and let the sun shine in
through a solid. The handle of an iron fry pan getsduring the winter are a natural way to have
hot by conduction. We insulate our house wallsseasonal shielding.
and attic to slow down the conduction of heatThe other way heat travels is by conduction
through the structure of the building.through materials. Insulation acts like a speed
Convection is the last type of heat transfer.bump slowing down the movement of heat
Convention refers to moving heat by movingthrough materials like roofs, ceilings, floors and
either air or water that has been heated.walls. The more insulation you have the slower
An example of convection that we use to heatthe heat moves. The R number rating on
our houses is a forced air furnace. The furnaceinsulation materials indicates how well they resist
heats air that is pushed through the house, by athe conductive flow of heat. The higher the R
blower, to heat up the house. This movement ofnumber the more it slows down the flow of heat.
warm air is an example of convection. Heat isFor more information on this read my article
carried, by the air, from the furnace to the house.titles........
Convection can also work against us. An exampleWe like convective heat transfer when warm air
is warm air flowing up a chimney that conveysmoves from the furnace through the house. We
heat out of a house in the winter.also like it when warm air moves from the house
In the summer, we have more heat than weto the cold coil of the air conditioner. We do not
want in our living spaces. We force heat to movelike convection when it helps heat escape up the
the wrong way by taking heat out of our houseschimney, around windows, or under doors.
and putting it out in the hotter outdoors. ThisSaving energy means having high efficiency
takes a large input of energy to accomplishequipment to move heat only to where we want
because we are "doing some work" against theit to go. It also means doing the best possible job
normal flow. It is like pushing water up hill, it takesof blocking or slowing down the movement of
a lot of energy.heat where we do not want it to go.
In the summer our furnace fan, moves warm airImproving your home's weather sealing, radiation
to the cold coil inside the ductwork. This isshielding and insulation are some of the very best
convection, using air, to move the heat from hotthings you can do to reduce your energy bills.
to cold.