# HVAC Test-Math Problems

• 06-13-2004, 11:27 PM
drfixit
I am trying to find a source that may tutor me or help me find a way to understand the math problems in the Model Energy Code Mechanical considerations test. I swear I passed it last time and someone decided to fail me anyway...but, that's just my own conspiracy theory..I also know that contractors have programs and tools to do these calculations for them...but, how do I passs this test? I am running out of time here...I HAVE FOUR DAYS TO GO TILL THE TEST DATE..(2ND ATTEMPT!) Please, anyone out there who can help me out? drfixit
• 06-14-2004, 07:37 AM
acmanko
Those skills should have been learned in High School. Give us an example test question.
• 06-14-2004, 11:56 AM
NormChris

Here are several typical example math questions that appear on certification and contractors exams.

• 06-16-2004, 10:38 PM
drfixit
O.K., ACMANKO! HELP A GUY OUT HERE.Example question:A master bedroom is 225sq. ft.One wall is 15x10, 2x4 construction-R13 insulation. Window is 8x5. Second wall is 15x10, 2x6 construction-R21 Insulaton. Window is 4x3.Skylight is 4x4,floor is R19,ceiling is R38, window glazing is .5 value,inside temp is 70, outside temp is 2 degrees.
1.How many BTU's per hour escape one sq. ft.of wall with R value of 20?
2.What is Thermal Conductance through opaque portion of the 2x4 wall?
3,What is the Thermal Conductance of 2x4 wall & 8x5 window?
4.What is Thermal conductance through opaque portion of 2x6 wall?
5.What is combined Thermal COnductance of the 2x4 wall & 8x5 window?
6. Thermal Conductance of the floor?
7.Thermal Conductance through the opaque section of the ceiling?
8. Thermal Conductance of the 4x4 skylight?

GUYS, HELP ME HERE!!!!anyone that can offer feedback so I can slove these and questions similar to these, I am having a brain FART or similar condition, thanks
• 06-16-2004, 10:42 PM
mattm
Is there a naked women standing in this room?
• 06-16-2004, 11:02 PM
Andy Schoen
Quote:

Originally posted by mattm
Is there a naked women standing in this room?
Figure 500 btu/hr for the naked woman, assuming she's alone... 1400 btu/hr otherwise... :D
• 06-17-2004, 12:29 AM
hvac3901
q=A*K*t1-t2
i will double check later and post again but i think this is it.
• 06-17-2004, 10:20 PM
hvac3901
a minor correction for the formula.

q = A * U * (t1-t2)

contact

ASHRAE
Fundamentals of Heating and Cooling Loads.

it is an CEU course book. excelent source for the info you want. trane manual also offers alot of heat ransfer information and load calculations
• 06-18-2004, 07:28 AM
acmanko
You worry about to many things, why put yourself through all that?