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# HVAC load calculation (former TRACE 700 user)2

## HVAC load calculation (former TRACE 700 user)

(OP)
I need to buy a new load calculation software. Mainly for load calcs and equipment sizing in small and medium sized commercial buildings. Software should use RTS and other modern methods and provide good documentation for review and "sanity check".
some features i really would like:
- Some building wizzard or other way to "see" the building I'm modeling. Importing PDF of the building and tracing on the plan would be great.
- having built-in building elements with actual U-values. For example studded walls should have the correct U-value accounting for thermal bridges
-

Some more details:
- I only have a few HVAC load projects a year (that may change, though)
- I use Revit for duct/pipe calculations, so i don't need any duct size features that some of the programs offer
- in an ideal world i would use a Revit plugin, but there doesn't seem to be a software
- i'm the only user here. some of the programs have very expensive flatrates for unlimited users, so that wouldn't help my company.

Here is what I had researched

1. I had used TRACE 700 and let the license laps: this is a very outdated software and seems overly complex, which can lead to errors. there is no way to " see" the building and one could inadvertently have wrong adjacencies and orientations without ever noticing. It also has no real-building element database for studded walls etc. i had to create my own walls with corrected U-values. i also didn't like that they never updated for actual improvements (e.g. more efficient user interface). importing gbXML seemed buggy. thsi may be a gbXML problem, but i ended up with many tiny surplus walls and had to spend more time cleaning up in TRACE than manual entering of the building would have taken. and again, since one can't " see" the rooms, errors can enter.

2. I tried the trial of TRACE 3D. They didn't address my above TRACE 700 complaints regarding building elements and real U-values. the software was very slow and buggy. In fact, I wasn't able to complete their tutorial building without crashing. Maybe that was back whne it was first introduced, but I'm concerned that a company that made software for decades publishes such buggy software at a steep price. it is quite pricey as it requires annual renting. The price isn't necessarily a problem, but for that price the software has to be very good.

3. Carrier HAP: they have an odd long request process for a trial software and a weird way to have the EULA acknowledged (so still don't have a trial version...). they seem to have a building wizzard, and I'm keen to see if it works the way I envision. Screenshots indicate it looks mostly similar to TRACE but is quite a bit cheaper. I'm concerned with them being so difficult already for just getting a trial version.

4. CHVAC: will try the trial thsi weekend (the trial is limited to 2 rooms, though), but it seems a cheap way to get small projects done. Does anyone have experience with their accuracy and user interface efficiency and reporting options?

5. Wrigthsoft universal: will try to get a trial. their website indicates this software doesn't get updated a lot.

6. IES: I'm a bit overwhelmed with all their different modules and it seems expensive. They don't seem to have a re-seller for my area, and the one reseller listed for US areas (not mine) has a website that looks like it was created in 1995. I'm a bit concerned that they make it more difficult and don't sell directly.

There are some other options, but they are not suitable. eQuest and Designbuilder don't seem to be suitable for load calcs (and I rather not hack around)

If anyone has opinions on the above software or ideas of other products, let me know.

### RE: HVAC load calculation (former TRACE 700 user)

Carrier has a simpler load calculation software called carrier block load - I found it to be the best simple one out there, with just all the major inputs needed to estimate cooling and heating loads.

### RE: HVAC load calculation (former TRACE 700 user)

(OP)
GT-EGR: I downloaded HAP demo and ran it in "load only" mode. what is actually the difference between their "block load"and the "system Load"? the latter doesn't have a demo version.
From what I saw HAP has the library per project. I didn't see a way to create new library elements that can be used elsewhere. Overall it seems very similar to TRACE 700.

I tried all above software,here my conclusion so far:
CHVAC: It has an optional "drawing board" to trace building plans. However, there is the issue that some values have to be entered in drawing board or in room properties table. If you enter a value (e.g. lighting data) in the wrong one, it will forget those data once you switch between drawing board and room table. I also didn't see an option to see the difference between block load and peak coil load (less in VAV systems). Maybe I just didn't see it, though.
Wrightsoft: it wasn't clear to me if it has the option to accurately calculate peak coil load. it seems geared towards a contractor that needs ductsizing, hydronic design and load all in one. that is reflected in the price ($2,200) and the plethora of features i don't need. My fear is it simplifies load calc for VAV systems and just adds all the loads without diversity. IES: yeah, I'm overwhelmed and wasn't able to do a load calc... to steep of a learning curve for just load calculation over a weekend. I also broke down and downloaded a demo of TRACE 700 again to have a 1:1 comparison to the above. Compared to all the above flaws, it seems not so bad. But I also downloaded TRACE 3D and actually like it (the load only version only cost$795). It was a bit sluggish, and with complicated building plans it crashed. but so far I like it the best and liked playing with it the most. the cost is the same as for CArrier Load calc, plus I can trace the building.

EDIT:since I seemed to have narrowed it down to "TRACE 3D Load", i wonder what experience people have with it?

### RE: HVAC load calculation (former TRACE 700 user)

(OP)
So I'm mow between "Trace 3D Load" and "IES". IES obviously has many more features. But just looking at the HVAC load calculation part for design purposes, what is the experience with either program (or a comparison)?

### RE: HVAC load calculation (former TRACE 700 user)

I'll be interested to hear what you select!

### RE: HVAC load calculation (former TRACE 700 user)

in carrier HAP software we can calculate by RTS method?

### RE: HVAC load calculation (former TRACE 700 user)

Try CYPETHERM LOAD. It uses RTS and it's free trial. http://cypetherm-suite.en.cype.com/

Although you are looking for software, what about excel sheet? It's simple as you want.

offtopic = I wonder how good is Revit for duct calculations - specially when calculating fitting losses ? Any tips

### RE: HVAC load calculation (former TRACE 700 user)

2
(OP)
I ended up buying Trace700 Load. And that despite the fact that it will be be discontinued in 2022, which gives me 3 years to find a replacement. i hope by then the below software get their act together.

IES seemed too complex and expensive for just load calculation. it is a nice software if you use all the features, though. i also think it is needlessly complex due to its history of being several different software (like they have 4 lighting modules). i wasn't even able to actually complete a load calc and see results. (all other software i tested i was able to do it withing reasonable time)

Trace3D looks nice, but has too many bugs. it also is less user friendly in regard that i see what each room consists of. For example in T700 i see the U-value fo the walls in each room (sanity check!!!). but what really steered me away are the bugs and inabilities to do things it should be able to do. Support referred to a v2 coming up soon, but i can't judge a software based on promised features and bug fixes.

Carrier System Load is much less sophisticated than T700. Considering the almost equal price I wonder why one would choose Carrier.

BTW, I also tried Revit load calc. It starts out by using really weird U-values for a given construction, doesn't use diversity and came up with much higher flowrates than T700. Like as in twice the flowrate. and you can't enter your own outside air design conditions and rely on what Revit decided to use. So you may as well just assume "1 cfm/ft²) and come up with a better estimate

### RE: HVAC load calculation (former TRACE 700 user)

Nice feedback.

By the way, do you like your results for duct calculations with Revit?

I always get wierd pressure loss in fittings.

### RE: HVAC load calculation (former TRACE 700 user)

(OP)
I use Revit for duct and pipe pressure drop calculations. Yes, fittings are a bit odd, especially when you go to 2D elbows etc. but it isn't more sketchy than the varying K-factors etc. that many sources use.
The pressure-drop in straight sections sure is accurate. I also add pressure drop equations into equipment, diffuses, dampers, louvers, valves etc. (In Excel I do a curve fit from manufacturer data to get a flow-pressure equation). So for straight sections and equipment I know I have good data. Most engineers still use an analog ductulators and then add 50% for fittings..... so my method is better . Revit also determines the critical path. and if i change a diffuser flow, or a louver size, Revit automatically adjusts without me having to look at tables etc. Once set up correctly, i trust it more than doing it by hand myself.

I think you can make fitting families and use your own K-factors. But to be honest, there are so many different K-factors for the same looking fitting if you look at all sources (ASHRAE, SMACNA etc.,) it seems to be more a guess than a science. I also use low-loss fittings when possible, and the standard fittings are not, so my design will be more conservative.

Note that you can and should create new fluids with different viscosity (i.e. chilled glycol).

I haven't tried out the new features for pumps in parallel and hydronic de-coupling etc. But it looks like Adesk is working on making this part even better.

### RE: HVAC load calculation (former TRACE 700 user)

Thank you so much , bro . I've always hesitated to use Revit in my previous design projects ( I used to prefer AutoCAD ) . Now , I have to retry Revit .

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