Heat Transfer

Heat transfer is something that occurs when the temperature between the outside and inside of your home has a 3 degree F or more differrence. The natural flow is from the heated area to the cooler area. Insulation is one method of addressing this and the ratings for insulation determines the time it takes for the heat to transfer. The higher the number the more time it takes. Insulation does not stop the transfer it just delays it.

Various materials have different insulating characteristics and some are considered good and some are not. Metal is not a good insulator where as cement is considered one of the better insulators.

Future Solar Home - The Venus Project

By getting a better understanding of what goes on around your home in terms of heat transfer you will be able to address what you find before you spend money inefficiently on your Solar Saving Project(s). Calling in a professional Builing Performance Auditor who will show you where your undesirable heat transfers are taking place and what you can do about it.

Radiant Barrier Bobs Story

This is another chapter in Bobs Story. Since insulation only delays and does not stop heat transfer, what other choices do you have? My personal preference is using double sided "Radiant Barrier". This is a product that is 2 sheets of a specialized aluminum foil separated by a strong-thin-flexible plastic. The one I have used had pin holes every square inch and came in 3 foot widths and a thousand feet in length.

In line with keeping it simple, lets get the idea that in your attic you laid out radiant barrier on your attic floor. During the summer time when the attic heats up, your radiant barrier bounces the heat away, preventing it from penetrating the ceiling below. In the winter time it bounces the heat from below, back into that space. In order to get this to work properly the radiant barrier must be installed correctly.

I came across radiant barrier in the late 80s in southern California. I was selling and installing this product for awhile. One day I got a call from Bob Hope's piano player. He told about one room on the second floor of his house that was hot, and no matter what he did it would not get any cooler. I went out to look at it and discovered that particular room was exposed to the sun via the attic for most of the day. When looking in the attic over this room there was between 3 and 4 feet of insulation. I told him I would like to install some radiant barrier to see if that will handle it.

He gave me the go ahead and the next day I installed it only above that room. The insulation that was above that room was spread out across the attic above other nearby rooms, leaving only the radiant barrier in that section of the attic. Later that day around 6PM he called me to tell me the room was at least 10 degrees cooler than it had ever been during the hot summer days and was cooler than the near by rooms. That was when I became a believer.

What Do You See

I like to look at heat transfer in an ideal manner. Like what if I could get a space to arrive at an ideal temperature and keep it there indefinitely without adding or subtracting hot and cold air! What I do know is this, there is usually a way to prevent unwanted heat transfer to some degree and is something that could improve energy efficiency and save you money on your solar plans.

Here are the ways heat gets transferred between the outside and the inside of your home.
1. From your roof to your attic to your ceiling to your space below the ceiling.
2. From the space in your home to your attic and then cooled or exhausted to the outside.
3. From windows or glass doors to the outside or from the outside to the inside through your windws or doors.
4. Through the walls of your home.
5. Through ducting in attic or crawl spaces.

Anytime there is a difference of 3 degrees farenheight heat will transfer to the cooler area. Addressing any unwanted heat transfer will improve efficiency in keeping your home cooled or heated the way you like it.

For number 3 there are a few things you can do.

A. Solar Window films. These come in various thickneses and materials. An added benefit is they can be an added security protection from extreme weather as well as unwanted entry (both physical and visual).
B. Solar shades. Order 30 Free Samples Today at The Shade Store! These come in wonderful designs and can be combined with window films for reducing light and adding some decor.
C. Awnings can also be used effectively to block the rays of the sun and will provide shade rain redirection and can make your home on the outside look better.
D. Double pane insulated and UV coated windows. These can be quite expensive and worth it in the long run. The UV protection becomes important when realizing that the UV rays from the sun pass through a window hit molecular particles inside your home causing them to heat up and can cause fading colors inside your home.
E. Sealing air leaks around windows and doors really do make a difference. And if you live in an old farmhouse with clapboard siding and plaster lathe walls with no insulation between (like our place for over 3 years in Central New York State)you may have experienced 20 mile an hour winds in your living room. Come our first spring I never made better use of a 50 pound box of nails and 2 cases of caulk.

For number 4 above I have 3 recommendations.

A. Radiant barrier

Rb 48125 - 48 inch X 125', Scrim Reinforced Perforated Radiant Barrier, Blocks 97% Of The Radiant Energy Entering The Home, Reduces Attic Temps By Up To 30 Deg

for new wood framed construction. There are specific types for this purpose.
B. Sealing with caulk any where a wall meets the ceiling, another wall or the floor. When dealing with the floor removes the wood molding before applying caulk. This can be the source of a major heat transfer leak.
C. Insulation. There are new technologies emerging in this area so be sure to get Bobs' Solar News so you don't miss out when these become available.

For number 5 above I have 3 recommendations.

A. Seal all ducts and check for leaks from time to time.
B. Insulate ducts. This will help maintain the temperate of the air flowing through them.
C. Seal any openings from crawl spaces through the floors of your home.

With your heat transfer under control, you are now another step closer to realizing your solar savings and another step taken to stop pollution for our planet. Thank You!

_________________________________________________________

Lower Your Energy Bill
Locate and Handle Energy Waste
Return On Investment 6 months or less!
Steve Belknap 813-545-9963
Building Performance Auditor
Tampa Bay Florida

Heat Transfer

Future Solar Home - The Venus Project

Radiant Barrier Bobs Story

What Do You See

Solar Today, Tomorrow and Beyond Free Newsletter Subscription - Fill In Your email address in the box below!

Solar Today, Tomorrow and Beyond
Free Newsletter Subscription - Fill In Your email address in the box below!