# HVAC vs. Thermo Module...



## Brentum (Mar 31, 2008)

I'm going to do one of these two as my profession dabbles somewhat in both. Mainly compressed air, dewpoints, and liquid pumps. I first thought was the Thermo and fluids. But looking at the HVAC questions, that seemed a little easier and more intuitive. However, most people here seem to be doing Machine Design or Thermo. And the few people that are doing the HVAC talk about a whole slew of books they want to have. (Do you have time hunt through 5-10 HVAC books?) Do you need a lot of extra reference material for the HVAC? Is there a reason most people aren't taking that one? Is my perspective out of whack that it seems easier than thermo?

Just curious. I know it's only 10 days to test time, I've been focused mainly on Fluids and HVAC as far as the topics. Pretty much figured I'd be taking the HVAC but not I am having second thoughts.

I just ordered an HVAC reference book that should be here this week, but it's the only one besides the MERM that was was planning on taking in (I have a Manufacturer's book with some head and pipe loss tables too). The Book is 2007 HVAC Equations, Data, and Rules of thumb by Bell. Never really had much HVAC in college compared to Thermo and MD, but my job as an applications/sales engineer in the pneumatic and liquid pump industry is a little closer to thermal and HVAC concepts, so I headed off in those areas.

So am I about to walk off a cliff here or what? I'm starting to get panicky....

Any advice?


----------



## Brentum (Apr 1, 2008)

Anyone have any advice?


----------



## Matt-NM (Apr 1, 2008)

After working through some HVAC problems (six-minute solutions, MERM, etc) I also considered taking the HVAC depth module, even though I have no prior HVAC experience. The questions seemed easier to me than the machine design or thermo/fluids questions. This idea was immediately shunned by numerous people. The main reason being that the afternoon questions on the HVAC module will be more difficult and require actual experience to be successful in. Most people commented on using 4 ASHRAE books for the afternoon HVAC section.

Another person commented on trying the HVAC aftenooon module twice without any actual HVAC experience, both times unsuccessful. I personally have no HVAC experience, and relatively little thermo/fluids experience. Thus, somewhat by default, I choose machine design. This seems to be pretty common.

See this thread from a similar question.

Hope this helps. Good luck.

http://engineerboards.com/index.php?showtopic=5304


----------



## Capt Worley PE (Apr 1, 2008)

I went machine design, so my advice would be of little use.


----------



## Brentum (Apr 1, 2008)

Yea thanks.

Wow, that is pretty discouraging. The Thermo module just seems so much harder, but if most of what you need for it is in the MERM, then at least I'd have it for the test.

I was going to work the HVAC module in the "the other board" Practice test this weekend (didn't have enough time to do a full 9 hours last weekend, so just did the breadth in a 4 hour block). Maybe I should do both and see how each goes. It's pretty 11th hour for all of this I know, but as I was working through the HVAC chapters in the MERM, no red flags went up. It's just been here recently I was doing a little research on what others experiences have been that got me questioning.


----------



## Brentum (Apr 3, 2008)

For better or worse I'll be doing the thermo/fluids module.

Thanks for the input folks. I feel like I am choose death by leathal injection over death my firing squad, so we'll see....


----------



## ufcfan (Apr 3, 2008)

I took the Thermo/Fluids module and I passed. Just like you I wasn't completely decided if I should had go with Thermo/Fluis or HVAC. What made me decide was the fact that even when those HVAC problems are easier, this module will possibly cointains the Constrols side of HVAC and I think this is not so straightforward. At least that's what I hear. Maybe someone in the forum can confirm.

Anyways, in the Thermo/Fluids module they included HVAC problems with the rest of the Thermodynamics, Heat Transfer, and Fluids problems.


----------



## Brentum (Apr 3, 2008)

Yea, sounds pretty reasonable.

I do work in an industry that's pneumatics and viscous liquid pumps.

But you don't really have to do a lot of calucations. The products have tabulated data for determining require BHP for a particular pump, etc. I suppose that constitutes more familiarity than the machine design which I haven't seen since college, or the HVAC which my industry touches on, but really that's it's own thing, and I hardly had any HVAC in college that I recall...

I am going to bring my friction pipe loss tables though, those have been pretty handy although the MERM has something similar.

Well, hopefully I have the same result as you!


----------



## tim1981 (Feb 10, 2013)

I'm digging this old thread back to the top because I need to decide too! I work in HVAC but I'm in a graduate program for thermal fluids. The advantage of HVAC is that is seems easier and the knowledge would be useful at work. The advantage of thermo is that it's more applicable to my classes, and a comprehensive review of the undergraduate level material would make the next 5 classes I have to take a little easier.


----------



## ikesdsu (Feb 11, 2013)

tim1981 said:


> I'm digging this old thread back to the top because I need to decide too! I work in HVAC but I'm in a graduate program for thermal fluids. The advantage of HVAC is that is seems easier and the knowledge would be useful at work. The advantage of thermo is that it's more applicable to my classes, and a comprehensive review of the undergraduate level material would make the next 5 classes I have to take a little easier.




I dunno if HVAC would be any easier than the thermo section if you haven't done it in your job for the last four years. If you have been doing thermo for the last four years in your classes it might be better to go that way.

As a side test, if you are given a RTU and all the psychometric points going through the unit could you find the mixed air temp before the coil or after the coils? Could you figure out the approach temperature of a cooling tower if you are given the inlet water temps and the outside temps? It isn't to bad if you have done it before, but if you had never seen it, you might be able to figure it out but it would take you more than 6 minutes. While I don't want to minimize what you know, I just don't want anyone to have to take the test twice like I did.

If I sat down with the fluids test, I would definately just sit there with my jaw hanging down because I hadn't seen any of the applied stuff before. But if you feel comfortable with the questions I put above, go for it.


----------

