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I've been using NOA-approved equipment for years, most manufacturers should have options available. What are you looking for in particular? Using that search page, leave everything blank except for the manufacturer and try manufacturers like Greenheck and Ruskin. For RTUs and other rooftop...

Energy Gauge Summit is what I've used. The UI isn't great but it gets the job done.

As IRstuff said, the numbers add up. You also have to remove the exhaust airflow from the supply: RA - EA + OA = SA The air that isn't returned will leave the room through openings to other spaces and as exfiltration.

There's no situation where your return air + outdoor air won't equal your supply air, that's simple conservation of mass. I haven't seen it but maybe some designs account for some sort of leakage or changes in air density?

Take a look at the formulas/examples in ASHRAE Handbook 2013 - Fundamentals, Chapter 1: Psychrometrics, section "Typical Air-conditioning Processes". You basically need to convert the heat transfer to a temperature change and use a psychrometric chart to plot the conditions.

Yes, that's my point. I was wondering why other posters brought it up.

@ChasBean1 Well I'm assuming that by cooling the air to 40° that it will be essentially saturated so basically 40/40 DB/WB. If you reheat to 54° from that point then you are around 54/46 -- and yes, as you stated your dew point would be 40°F at this condition. In most of my typical...

ASHRAE Handbook, Fundamentals, Chapter 16 "Ventilation and Infiltration" has a lot of information on this. With 1000 cfm ventilation and 1000 cfm exhaust, your building is essentially neutral, although you'll still get infiltration due to effects like wind pressure. Also if you don't have...

I'm still not clear on why some posts here say that the air would have to be cooled to below 54°F and then reheated. I apologize if I'm missing something obvious here. Would anyone mind drawing that process on a psych chart to illustrate it? Cooling to 40° then reheating to 54° would result...

Thanks DrRTU, I'm going to review that link. I actually think I found the accompanied lecture on Trane's youtube channel. Can you elaborate on what you meant by "I doubt you will be able to achieve your desired wb over the complete range w/o reheat or face/bypass."? Thanks.

I've been wondering how a specific coil behaves under conditions other than its design conditions, and particularly relating to part-load conditions and the change in the sensible heat ratio (SHR) of the coil. If anyone has any good reading materials on this, I'd be happy to do my own research...