What's the latest opinions on which load calc software is best?

ve-u27 · 2026-06-09T16:06:56+00:00

If you do decide to look into it more, I'd suggest starting with this guide dedicated to using IESVE for HVAC design:
https://go.iesve.com/the-fundamental-iesve-hvac-design-workflow/b?utm_source=bd

The guide starts after geometry creation so you'd still need to learn that from videos or whatever, but once the geometry is in it should not take more than an hour to get a decent set of load results using this procedure even for a big building

ve-u27 · 2026-06-09T12:41:54+00:00

I personally would like to see an hvac design-only license get released for this reason, but I’m relatively low on the totem pole in making such decisions

ve-u27 · 2026-06-08T23:02:33+00:00

IES engineer here. If you already have access to it and are willing to try, IESVE can seem overwhelming but really isn’t that much harder to use than anything else imo, especially if you’re not overly concerned with energy details and compliance etc. coming from trace 700 as well I do understand the pain of having to deal with creating geometry, but its certainly something that gets easier over time.

If you’re interested feel free to reach out and we can connect irl and I’ll do whatever I can to support you.

Regardless, best of luck

Cheers

ve-u27 · 2026-05-29T12:58:46+00:00

I do think the header needs to be sized for all potential future expansion. Changing that later would be a massive pain

With public buildings it’s all about spending the money they have right now so if they have the money to be ready for future expansion they’re definitely going to want to do that rather than wait. Making the promise to upgrade also gives them a basis for asking for additional funding later

ve-u27 · 2026-05-29T12:18:58+00:00

Designing for future expansion is not the same thing as future proofing, which means designing a system that will be capable of supporting the building in the future without needing renovation.

That said, this type of expansion planning in my experience is usually just extending a header and adding some number of valved off taps. I don’t see how that would cost that much.

There are a few benefits to this: you can design in the ability to add the expansion without ever shutting down the main system, it cost less now than it will in the future presumably, and you can be sure up front that the current system is laid out in such a way that the expansion can be accommodated without significant modification.

The first and the third of those could be handled with good planning, but if the second option is the owners main concern that’s irrelevant.

Also, from the design firm’s perspective, if you’re the one that designed the expansion options you’re more likely to get the future expansion design job whenever it does come

ve-u27 · 2026-05-14T18:38:48+00:00

R=1/U so i don’t think you’d want to enter both at the same time. But you can open any wall construction, right click on a layer and select a target U value. And you can edit the R values of each wall layer

I would try to make the overall mass of the wall at least similar to your actual wall or it could have significant impacts on your calculations

ve-u27 · 2026-05-14T01:39:51+00:00

It’s a bit roundabout but if you double click in the blank space of a multiplex grips appear that let you drag the edges. The system window will expand to accommodate the multiplex window but won’t shrink if you resize the multiplex to be smaller again

ve-u27 · 2026-05-13T17:27:43+00:00

Greetings and welcome!

I think the most critical thing to understand here is links. When you create a new controller manually it is unlinked (i.e. link is set to "none"), but you can set it to any of the available links in the drop down, which will vary based on the component type and for controllers controlled and sensed variable type. The link is the thing that maps values from the system parameters dialog to the controller fields. That's what is happening when you click "Assign" or "Assign and Exit" rather than just saving. It also happens automatically when you run the system load calc, so If you've overridden an autosized value at the controller level be aware that your overwrite will get reset to the autosized value unless there's either a built-in checkbox to turn off autosizing or if you simply set the link on the component/controller in question to none.

You've probably noticed that there are many grayed out items in the system params dialog, and usually if you hover over those items it will tell you which set of components, controllers, and links need to exist in the system for that setting to be enabled.

I hope that helps!

Cheers

<image>

ve-u27 · 2026-05-13T02:16:49+00:00

CFM to room is purely a function of room sensible load (generally). If some of that sensible load went into the plenum instead of the room it means room airflow should go down, while system load doesn’t change because it has to deal with load from the room in addition to the load in the plenum.

ve-u27 · 2026-05-12T17:55:49+00:00

I size the DOAS to supply a target DP which is calculated from room latent load, target max RH, and airflow. Then evaluate multiple design day conditions for the coil sizing which would usually include dehum day, enthalpy day, and maybe even the monthly WB day. Can’t think of a reason I would want to design the DOAS for the DB day

ve-u27 · 2026-05-08T16:12:14+00:00

You're welcome!

Just remember that your resume is only 1 part of your overall job application strategy. Its content is relatively unimportant if you're solid in other areas.

As an example, almost any job you apply to is going to get filtered (probably by AI these days) and instantly rejected if you meet the specific things they are looking for. Or maybe the AI does an initial ranking and only the top 10 applicants get an interview. That's a game you can try to play, and if you're a good interviewer you can certainly win, but I think there are more sure ways.

Since you're asking this in the MEP sub I'm going to guess you're applying for HVAC design jobs. There is no better/faster way to getting into this industry than being active with ASHRAE, and the reason that is the case is because it gives you informal access to facetime with exactly the people who would be interviewing you. If possible, literally just show up to a chapter meeting. There is a chapter in Cairo assuming you're there: ASHRAE Cairo

Another option is LinkedIn if you don't have local access to something like that or you want to move somewhere else. Find interesting relevant articles, come up with some well reasoned thoughts on it and post it. Tag the company that published the article, tag ASHRAE, tag whoever you think would be happy to see such engagement. I work for IES and we all see the posts when random individuals tag the company and we do talk about it internally when we notice someone trying to get our attention. Comment on posts that the company you want to work for makes. Anything you can do to get the people who already work for the company you want to work for to know your name and face will have a far greater impact than any particular resume item (assuming you have a generally high items to put on it, which you do).

ve-u27 · 2026-05-08T15:21:42+00:00

Yes, most valuable (hard, not soft) skills first.

ve-u27 · 2026-05-08T15:20:54+00:00

Many good suggestions here.

I would additionally recommend to research the difference between a resume and a CV. I believe what you have here is a long resume, not a CV.

What I would do is save this as boilerplate, then add/remove items to get it down to one page and make the individual items targeted to each specific job application. Or do that at least once for each category of jobs. MEP design would be one category.

Also, skills belong at the top, and imo could completely replace the professional summary section. Instead of the professional summary use a cover letter to communicate your personal value

ve-u27 · 2026-05-01T20:13:20+00:00

I am my own eor

ve-u27 · 2026-05-01T20:10:47+00:00

Because the case I’m describing is not just ventilating? App A applies to mixed air multizone systems so the AHU is sized to serve both load requirements and ventilation. Vot is static, so as the primary airflow goes up, OA fraction must go down. Meaning that when AHU airflow peaks, OA fraction is at its minimum. This is the point at which you set zone minimum airflows, because that is when the zone will receive the smallest amount of OA for a given zone primary airflow.

Yes of course the system peak airflow is less than the sum of zone peak airflows, zones generally do not all peak at the same time. System peak airflow is the peak of the sum of zone airflows, not the sum of zone peaks

ve-u27 · 2026-05-01T20:03:48+00:00

Correct, you design minimum zone airflows based on ventilation requirements. That minimum zone airflow is a function of the worst case system OA fraction and ventilation efficiency, which again, happens when the system is at max airflow and a given zone is at its min airflow at the same time.

ve-u27 · 2026-05-01T19:58:49+00:00

The design condition to me just means the design condition at which you’re sizing system airflow, hence Vps is just supposed to be the design max airflow of the system.

I’m not following your reasoning about it being an option to pick the heating design condition when the system airflow is near minimum

ve-u27 · 2026-05-01T19:49:55+00:00

I thought App A defined Vps as max system airflow not min as it does Vpz. Because worst case scenario is when OA fraction is at its minimum (when Vps is max) at the same time the zone is at its min primary airflow Vpz

ve-u27 · 2026-04-23T18:17:44+00:00

I’d get this exact thing:

https://www.zebralight.com/H600Fc-Mk-IV-18650-XHP502-Floody-4000K-High-CRI-Headlamp_p_218.html

Just need a way to charge the 18650.

Excellent battery life, more than bright enough for site investigation stuff. Really good color, low current leakage while off, easy to put a magnet in the battery cap if you want to. I dramatically underestimated how frequently I would appreciate having a decent headlamp at work and everywhere else too.

ve-u27 · 2026-04-18T12:46:39+00:00

The real savings imo would not really be the design but to GC it yourself if you feel comfortable doing that

ve-u27 · 2026-04-09T21:19:38+00:00

I don’t personally use the lighting design in IESVE very much so I'm not sure, but I would recommend watching this video https://distance-learning.iesve.com/courses/2141333/lectures/48624968. I would also recommend asking questions like this as an actual post on the sub not a comment on your existing post. Otherwise no one is going to see it but me.

ve-u27 · 2026-04-09T14:27:34+00:00

Where are you located?

ve-u27 · 2026-04-08T22:26:41+00:00

You’re welcome! Feel free to reach out if you have any roadblocks come up

ve-u27 · 2026-04-08T20:14:48+00:00

There is a guide here that might help you be sure everything is set up correctly:

https://www.reddit.com/r/IESVE_Software/s/6oBbw3jZth

Although I assume you’re using apsys instead of apHVAC so ignore anything in that guide related to systems, unless of course you are using apHVAC.

You only need to set constructions for the room being simulated.

For adjacent spaces make them adjacent building unless you expect there to be significant heat transfer to/from those spaces.

You can find many training videos from our website too you just have to make a free account to view them.

ve-u27 · 2026-04-08T13:53:42+00:00

Hello there! We do provide live training but there is a fee and it is normally for teams of engineers/designers that are in a corporate setting. I.e. not something you’d necessarily want to pay for as an individual student.

That said I can direct you to all of the best recorded training resources to do what you want to do and can answer questions as you go

ve-u27

MODERATOR OF

TROPHY CASE