Could anyone help me calculate a breakdown that shows  heat loss in BTU/hour that adds up to 100% and shows % or subtotals for the sub-categories that add up to 100% based on  u values and Area for the sub-categories I guess per square foot of area in question. For a stated day with stated temperature inside of 70 degrees and outside temperature of 40.
The areas in questions are: 
 
-Ceiling. with an R4 value of insulation
-1st Floor to unconditioned basement 2x8 empty cavity, 3/4 pine groove plus 1/2 hardwood -No insulation
-Windows/Glass casement windows double pan glass
-Exterior Walls with 3/4 pine siding, 3/4 insulation, 1/2 drywall
-Air change
I would be grateful for any advice you guys could provide!
Thanks 

Views: 212

Reply to This

Replies to This Discussion

Answer equals = U * A * T

As you are missing A or area.... for the first one

What the Delta T & A is for the second

What the U value & A are for the third & fourth...

Your question asked is impossible to answer - you fill in the blanks & you have your answers

I was thinking that in order to stay away from a full blown home calculation, I would keep it simple so I could learn the concepts. I suggested a one square foot of the material, temperatures ranges are 40 outside to 70 inside. 

Knowing the area (one square foot) and knowing the temperature range... Can I figure the rest?

Thanks

Hi Luis,

It gets a lot more complicated than what you are asking for, but learning is something a lot of people should be doing. 

Your one ft² example will give you an idea as to the heat loss per foot in one hour, but only for the given temperature.  If you want the loss per year, you add in the heating degree days.

Sean's equation Q = U x A x ▲T gives you the btu's for the area and the u-value specified.

If you want to estimate the energy lost for a year, use: Q = U x A x HDD x 24.

If you want to play with a very basic heat loss calculator, try Gary's over at build it solar:

http://www.builditsolar.com/References/Calculators/HeatLoss/HeatLos...

Bud

RSS

Home Energy Pros

Home Energy Pros was founded by the developers of Home Energy Saver Pro (sponsored by the U.S. Department of Energy,) and brought to you in partnership with Home Energy magazine.

Latest Activity

Tim Reynolds replied to Alan Gindt's discussion Minneapolis Blower Door, Pressure Pan, and Bacharach CO 3 For Sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"I was wondering if you would sell the pressure pan by itself and for how much? Thanks -Tim"
2 hours ago
Profile IconTim Reynolds and angela hines joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
2 hours ago
Profile IconAllen Rathey, Kevin Love, Shannon Kahl and 1 more joined Home Energy Pros
3 hours ago
angela hines replied to Alan Gindt's discussion Minneapolis Blower Door, Pressure Pan, and Bacharach CO 3 For Sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"What is the price for them together? What is the price just for the blower door set?"
21 hours ago
Alan Gindt replied to Alan Gindt's discussion Minneapolis Blower Door, Pressure Pan, and Bacharach CO 3 For Sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Yes"
21 hours ago
Anna Jursik's blog post was featured
23 hours ago
Everblue posted a status
"New Energy Auditor Jobs posted on our Massachusetts Job Board! Check them out: http://www.everblue.edu/hiring/job-board/massachusetts"
yesterday
Everblue posted events
yesterday
angela hines replied to Brooke Ingram's discussion 3 full sets of testing equipment available for sale! in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Hi is the Minneapolis blower door set still available?"
yesterday
angela hines replied to David Allen's discussion Like new! Great Deal! Minneapolis Blower Door system, Duct Blaster and Flir i-7 Infrared Camera for sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"I am interested in the blower door and camera. Are they still available? If so i will buy. Please…"
yesterday
angela hines replied to Alan Gindt's discussion Minneapolis Blower Door, Pressure Pan, and Bacharach CO 3 For Sale in the group Energy Auditing Equipment for Sale, Trade or to Purchase
"Is this still for sale? I am interested and would want to buy."
yesterday
Anna Jursik posted a blog post
yesterday

© 2014   Created by Lawrence Berkeley National Laboratory.

Badges  |  Report an Issue  |  Terms of Service