{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

11_Annual%20Energy_2008

# 11_Annual%20Energy_2008 - Lecture 11 Calculation of Energy...

This preview shows pages 1–23. Sign up to view the full content.

Calculation of Energy and Costs for Annual Heating Lecture 11.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
News you can use: Discussion forum on the Arch. 140 WWW site – clearinghouse for HW and Final Project questions
Let’s review: A figure called UA ref which was the rate of heat loss from a building expressed in the units of Btu/Hr F: UA ref = ( (UA)) + (F x P) + (VHC air x VOL x AC/hr) UA ref was one of the terms in our balance point temperature formula along with Qi (internal gains). UA ref .

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
You will remember that balance point temperature, the outdoor temperature at which the furnace must come on, was defined as: T bp = T therm - ( Qi / UA ref) An assumed balance point temperature of 65 F is an important assumption in the conventional use of the degree day method for calculating annual energy consumption for heating a building. Balance Point Temperature .
Professor G. Z. (Charlie) Brown advocates a balance point way of thinking.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Is the Balance Point Temperature high or low? This is sort of a building science version of ‘am I hot or not?’ An aged, single- family, detached house in the country.
Dover Centre “the Right Place to Grow Your Business” Is the Balance Point Temp. high or low?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
My old apartment in Back Bay Boston Is the Balance Point Temp. high or low?
The Saskatchewan Superinsulated House Is the Balance Point Temp. high or low?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
A well populated gymnasium Is the Balance Point Temp. high or low?
A graphic look at Balance Point Temperature Net energy loss if negative Net energy gain if positive Temperature scale used to locate thermostat setting, balance point temperature and rate of heat loss

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
A graphic review of Balance Point Temperature Setting up a problem: Assume a 10,000 Btu/Hr rate of internal gains (Qi) and a thermostat setting of 72 F Thermostat setting Rate of internal gains (10,000 Btu/hr)
T bp = T therm - ( Qi / UA ref ) Changing the rate of heat loss

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
A graphic review of Balance Point Temperature The effect of different UA ref (heat loss rates). Higher rate of heat loss yields higher balance point temperature UA ref = 2000 Btu/Hr F
A graphic review of Balance Point Temperature The effect of different UA ref (heat loss rates). Higher rate of heat loss yields higher balance point temperature UA ref = 1000 Btu/Hr F

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
A graphic review of Balance Point Temperature The effect of different UA ref (heat loss rates). Higher rate of heat loss yields higher balance point temperature UA ref = 500 Btu/Hr F
T bp = T therm - ( Qi / UA ref) Changing the rate of internal gains

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
A graphic review of Balance Point Temperature With UA ref fixed at 1000 Btu/Hr F reduce internal gains from 10,000 Btu/hr to 5,000 Btu/hr Qi = 10,000 Btu/hr UA ref = 1000 Btu/Hr F
A graphic review of Balance Point Temperature With UA ref fixed at 1000 Btu/Hr F reduce internal gains from 10,000 Btu/hr to 5,000 Btu/hr Qi = 5,000 Btu/hr UA ref = 1000 Btu/Hr F

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
T bp = T therm - ( Qi / UA ref) Changing the thermostat
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern