# Does the volume of a space matter when solving a heat loss equation

**URL:** <https://community.blackspectacles.com/t/does-the-volume-of-a-space-matter-when-solving-a-heat-loss-equation/3273>\
**Category:** Project Planning & Design\
**Created:** [July 11, 2021, 11:28pm UTC](https://community.blackspectacles.com/t/does-the-volume-of-a-space-matter-when-solving-a-heat-loss-equation/3273 "2021-07-11T23:28:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Shikha](https://blackspectacles.com/uploads/images/13.png) [@Shikha](https://community.blackspectacles.com/u/Shikha)\
**Post date:** [July 11, 2021, 11:28pm UTC](https://community.blackspectacles.com/t/does-the-volume-of-a-space-matter-when-solving-a-heat-loss-equation/3273/1 "2021-07-11T23:28:00Z")

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I received a practice question where I was given all the factors to utilize the heat required equation (pg 163 of the handbook, last equation). The BTU/H was already calculated and a given, the temp differential was given, and so were the degree days. But I was also given a diagram with dimensions to the space…

Was I supposed to use the dimensions somehow? the only other equation I could think that needs dimensions is BTU/h=U x A x Temp Diff…but the question already had a BTU/h, and no given U value. And the question was specifically about heat required?

For all the equations in the handbook that involve BTU/h…they all mean the same thing for that variable right, heat energy per hour? It doesn’t magically change meaning per what equation you’re using, right?

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**Author:** ![coachdarionziegler](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.blackspectacles.com/coachdarionziegler/32/1272_2.png) [@coachdarionziegler](https://community.blackspectacles.com/u/coachdarionziegler)\
**Post date:** [July 16, 2021, 7:26pm UTC](https://community.blackspectacles.com/t/does-the-volume-of-a-space-matter-when-solving-a-heat-loss-equation/3273/2 "2021-07-16T19:26:13Z")

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Hi @Shikha,

I’m afraid I don’t have the resource the resource you’re looking at, so I’m not 100% sure, but perhaps the diagram was a read herring? Or otherwise you were meant to use a different equation and the problem was asking for something slightly different than the heat required?

BTU/h will always represent the same thing. A BTU is the amount of energy it takes to raise the temperature of water by 1 degree fahrenheit. BTU/h is a unit of power (remember, power=work/time), which is equal 1 BTU being output in an hour.  
I had to visit this website to refresh myself on the best way to describe btu/h:  
[https://energyeducation.ca/encyclopedia/BTU/hour](https://energyeducation.ca/encyclopedia/BTU/hour)

I’d definitely check out some of the PDD “OBJECTIVE 1.2: DETERMINE THE SIZE OF MECHANICAL, ELECTRICAL, PLUMBING SYSTEMS AND COMPONENTS TO MEET PROJECT GOALS” lectures on this for more information. I really relied on these lectures to bring me up to speed on HVAC and heat loss calculations.

These are a few good ones:

> **[Determine the Heat Losses | Black Spectacles](https://blackspectacles.com/videos/determine-the-heat-losses)**

> **[Transmission Infilitration Ventilation | Black Spectacles](https://blackspectacles.com/videos/transmission-infilitration-ventilation)**

> **[Heating Load Calculation - Part 1 | Black Spectacles](https://blackspectacles.com/videos/heating-load-calculation-part-1)**

> **[Heating Load Calculation - Part 2 | Black Spectacles](https://blackspectacles.com/videos/heating-load-calculation-part-2)**

> **[Determine the Overall Heat Loss | Black Spectacles](https://blackspectacles.com/videos/determine-the-overall-heat-loss)**

> **[Overall Heating Load Calculation | Black Spectacles](https://blackspectacles.com/videos/overall-heating-load-calculation)**

Hope this helps!  
-Darion