set of psychrometric charts?

[sayed]

well apparently the full set of ashrae handbooks only has a single psychometric chart . But i'm doing practice problems that require the use of non-standard ones

does anyone have a pdf with different elevations, etc. ?

 

[Slay the P.E.]

There’s a high altitude one (5,000 ft) in the NCEES exam booklet.

We have extended range (from 20F to 120F) for sea level for free download here: https://www.slaythepe.com/free-resources.html

 

[andy10889]

The Merm has the low temp, std, and high elv charts.

 

[matt267 PE]

@sayed, 

Just as a reminder, during the actual exam, do not write on your own psychometric charts. You can only write in the exam booklet. 

 

[Guest]

.

 

[sayed]

i'm doing psychometric problems and keep getting them wrong. I'm off by just a little bit on enthalpy readings and it ruins the entire solution

i'm getting so worried

 

[Slay the P.E.]

Are the deviations bad enough that they lead you to wrong answer choices? The answer choices typically wouldn’t be that close. Can you provide an example?

 

[sayed]

Are the deviations bad enough that they lead you to wrong answer choices? The answer choices typically wouldn’t be that close. Can you provide an example?

yes they are. these questions aren't from the NCCEES practice.

i'll have to look for them. practicing on ncees now.

quick question, are the lines for "wet-bulb" perfectly parralell to enthalpy lines?

i'm using the coolerado sheets (which are nice and big, 11x17) but they do not have the lines of constant enthalpy. i'm off by 0.5-0.8 BTU/lb  everytime i read them. (as opposed to the answers)

 

[namod65]

yes they are. these questions aren't from the NCCEES practice.

i'll have to look for them. practicing on ncees now.

quick question, are the lines for "wet-bulb" perfectly parralell to enthalpy lines?

i'm using the coolerado sheets (which are nice and big, 11x17) but they do not have the lines of constant enthalpy. i'm off by 0.5-0.8 BTU/lb  everytime i read them. (as opposed to the answers)

No they are not parallel but they are very close. To the point where it shouldn't make a difference if you follow them up to read enthalpy.

This is the chart that I've been using and I've always been close enough with the enthalpy readings on it. By far the easiest chart to read enthalpy on that I've found. I personally don't care for the ASHRAE chart. I'll only use it if I end up needing to draw on a chart.

http://www.handsdownsoftware.com/carrier-chart.pdf

 

[sayed]

i'm about ready to give up. i'm getting every simple psychometric problem wrong. i'm simply not matching the solutions at all.

it's absolutely ridiculous that someone with poor eyesight could never pass this exam due to the chart readings

 

[Slay the P.E.]

i'm about ready to give up. i'm getting every simple psychometric problem wrong. i'm simply not matching the solutions at all.

it's absolutely ridiculous that someone with poor eyesight could never pass this exam due to the chart readings

I would say the real issue is with whoever wrote the problems you’re working on. Getting an enthalpy of 30.6 BTU/lbm instead of 30 BTU/lbm (a 2% difference) should not lead you to picking a wrong answer choice. Please post an example of a problem where this has happened...

 

[Ramnares P.E.]

Agree with @Slay the P.E., the answer choices in the prep material you are currently using should not be formatted such that a rounding error or small decimal change is enough to meaningfully change the answer.  Since this is causing a serious blow to your confidence, why don't you work the NCEES prep material and see if you run into similar issues?