×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Heat loss from dome house.

Heat loss from dome house.

Heat loss from dome house.

(OP)
Hello everyone!
I have one serious question, that needs solving. I live in Latvia (close to Finland, Norway etc.) so the weather is quite cold. So I would like to calculate what would be the heat loss from geodesic dome if I built one here. As far as I understand the heat loss can't be calculated in the convential way.
I know how to calculate heat loss from a pipe (and I also know that too little insulation will cool the pipe down due to increased surface area). So I think this will apply to hemispheres too!
Every possible size, resistivity, temperature -everything is avialable, I just need someone to give me some tips on how to advance further with my problem.
I am familiar with PHPP program (if that helps.. but I think it is not designed for spherical calculations!)
Thanks a lot!

RE: Heat loss from dome house.

Heat loss is a function of the materials Heat Conduction value watts/m2 of surface area and per meter thickness x difference in temperature across the material.  All you need to know is that and the surface area of the hemisphere.

From "BigInch's Extremely simple theory of everything."

RE: Heat loss from dome house.

I think BIG has it pretty much right!!

RE: Heat loss from dome house.

The dome shape minimizes the exposed area in a cold climate.

One other factor is the materials used. Many materials have great ability to absorb internal heat, which can result in a lower energy requirement . The lighter the structural materials above grade, the lower the ability to retain heat, whilr heavy materials inside the envelope provide more comfort and lower heat requirements and equipment capacities.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

RE: Heat loss from dome house.

It will depend on how your residence is constructed. Most of the dome builders are claiming 30% less. Here is a link to resources.

http://www.eric-randall.com/domes/

RE: Heat loss from dome house.

(OP)
But isn't heat loss from hemisphere greater than from straught surface? Same as tubes - there are critical insulation at which the heat loss gets even greater (can't remember the formula now..)

RE: Heat loss from dome house.

You must be careful how and what you evaluate in the various alternatives.

Floor area of a hemisphere is almost 2 times that of a box of equal volume, but you could only stand up in the center of the hemisphere.

Surface area of a hemisphere, not counting floor areas, is 77 %that of a box of equal volume.

Total surface area of a heimisphere, counting floor areas, is only slightly less than that of a box of equal volume.

If you lose heat in winter, or gain heat in summer, through the floor, go with a box. If your heat transfer is through walls and ceiling, go with a dome.  If your heat transfer is only through the ceiling, go with a box, insulate the ceiling heavily... domes are all ceiling.  As heat generated inside tends to be convected upward, a box might present less transfer area through its smaller ceiling.  

If you want to stand up in the corners, go with a box, or add a cylinder below the dome and increase the surface area accordingly.

You may want to include construction costs too.  Isn't a dome considerably higher?

From "BigInch's Extremely simple theory of everything."

RE: Heat loss from dome house.

Just to be clear, a geodesic dome is not the same as a hemisphere. The geodesic dome has a larger volume and smaller footprint than a hemisphere.

There are a few calculators out there for you.

http://www.desertdomes.com/dome3calc.html

For detailed information, you need to contact one of the firms that specialize in the design and construction of these products.

RE: Heat loss from dome house.

Quote:

"As heat generated inside tends to be convected upward, a box might present less transfer area through its smaller ceiling."

Well you certainly wouldn't want to call the "more vertical" portions of the dome "ceilings" instead of walls.  And the heat might gather in a smaller central part of the "ceiling" of a dome anyway, instead of being spread across an area as wide as the roof of a square.

In the end, this math problem gets quite complex, involving some ugly differential calculus.  Alternately, (my preferred solution) you find someone with a geodesic house and ask what their heating bill is.

Then there's this thing, which always intrigued me:
http://www.youtube.com/watch?v=mYOEoRK71_E



 

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources