Heat load/loss program

Dof3

I do use this program and like how easy it is. I sometimes wonder about some of the calculations myself. I do go by the CFM and btu ratings but sometimes I add a little for safety. I think the guy who made the program also started HVAC-talk.com. He has since sold it and moved on. The site ain't what it used to be.His name is Don Sleeth and he would probably answer any ? you might have. Good Luck!!

Paul Mitchell_2

Heat load/loss program

Hello all
Just wanted to throw a question out there. I had a program I used for years it was great. The person who developed the program died and I didnt want to keep using a program that would offer no support or any updates. So I purchased a new program HVAC-Calc. Great the way it operates and easy to use but I usually do not agree with the figures. This is just me looking at the house with the old rule of thumb and what I think it should be. Anyone else use this program and run into this?

John Cockerill

You can get another from slantfin.com You can compare results.

John Cockerill Exquisite Heat
www.Exqheat.com

Ted_9

When I use the program, I keep the construction very loose and dont add any extra r values. I'm very conservative. I add 20% when I'm don and I'm still under what most other contractors that dont use the program are.

PATRIOT HEATING & COOLING, INC.

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Wayco Wayne_2

I use Wrightsoft

and it usually gives me lower than I expect btu's. I have been using 2 stage furnaces in forced air apps as a hedge against mistakes. If you have entered accurately though it usually is accurate. WW

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Constantin

I've used several...

... You can read my profile of HVAC-Calc over in the "On the Job" section, or a slightly updated one on my web site. IMO, it's a good program if all you want to do is heat gain and heat loss. I would NOT use it for duct sizing without paying very close attention because the program assumes that you'll use the ducts for heating and cooling.

When I compared my results to those of the Wright-soft wielding contractor, we came within 10% of each other, his being lower. However, he was also gunning for 0°F design-day conditons, while I was going for -15°F. Truth is, any program that claims to be Manual-J compliant should produce the same results.

I found other programs like the Heat Explorer from Slant-Fin, HDS' heat loss estimator, and Firedragons software less intuitive to use for me. I am sure that these packages work perfectly for a number of other people, however.

For me, HVAC-Calc is on the right path not because of the results, but because the program has a well-organized component/wall/etc. tree that makes drilling down to components fast and easy. Also, you can play around with zoning to see how re-arranging zones can shift loads within the house.

There are, however, a number of glaring omissions, such as user-configurable R-values for walls, garage doors, HRV & ERV's, etc. that seem to indicate that HVAC-Calc doesn't do its heat loss empirically but rather relies on lookup tables with values from Manual-J. Nothing wrong with the approach if that's what he did (it helps speed things up), but I would have given "power users" additional options like the ability to turn off heating for duct work calcs, custom R-values, etc.

Constantin

He's certainly an interesting character...

... I got banned once from HVAC-Talk because I posted a technical question about the program when he didn't reply to an e-mail. He said I was hurting his business... no tech support questions about HVAC-Calc are allowed at HVAC-Talk.com. I guess people are supposed to think HVAC-Calc is perfect? It's my understanding that he, BOSS, is still around on the HVAC-Talk site but that someone else is actually runs the show.

IMO, this was predictable. Don ran his site as a contractor-centric, homeowners-are-barely-tolerated operation. The culture is wrong because there is a lot of trash-talking, engineer and HO-bashing, etc. going on alongside the more interesting threads. As a result, I'm sure that other HO's like myself either got banned or turned away for more hospitable sites and let the boys be boys in the locker room.

It's too bad though, because there are a number of very good techs that post on HVAC-Talk and there certainly should be a need for a homeowner-centric site that deals with 93% of the US' heating systems. Yet, Don seemed to think of his site as a mere vehicle to sell more copies of HVAC-Calc... sort of like hobbling the best web selling engine on the internet with a bookstore, way back when (Amazon.com)

Ultimately, Don probably had a very hard time competing with free on the one end of the spectrum (heat explorer) and integrated suites like Wrightsoft at the other end. I predict that if he and the other vendors of independent solutions don't come up with a common data interchange format, they'll suffer the same fate as Lotus 1-2-3, Borlands databases, Wordperfect, etc. and become very small players in a big market.

There is a reason that MS Office killed the competition and it has nothing to do with the inherent superiority of all of its components but how well they worked together. Similarly, none of us want to re-enter the same data 6 times, just so we can use HVAC-Calc for heat loss/gain, ductwork calculators, cost estimators, etc. No, we expect one suite to do that for us, and while pricey, Wrightsoft seems to offer that level of automation in a scalable package.

Paul Mitchell_2

Guys

Thanks for the in-put. I went to extremes to do a fictional load with both programs. They were within 500 Btu's I realized after this that the other program defaulted to..for example R-11 in the walls. Fine if you want a kick **** fudge factor but not very good in terms of proper sizing and eficiency. My old program reverted back to these settings every time. I like that the HVAC-Calc retains the R factors and details to save double entry. I am going to check out the wright-soft.
Thanks

Bob Forand

I use HVAC Calc regularly. I also feel that this program is light in the end result. I called Don Sleeth ONCE because of a problem. I put the program on my computer and sat right next to another user and we input identical criteria. We came out with different results, the problem is in the infiltration.
When I called him I got "What do you want me to do "? I told him I would like him to do a room with me to compare results. He told me he was too busy.
I am looking for another user friendly program so I can send his packing. I am also adding 20% to the end and changing all N walls to NE.

Constantin

I see...

... another "satisfied" customer. :-)

Despite Mr. Sleeths in my mind belligerent attitude towards me, I found his program to be quite useful. It gave me a good starting point from which to make decisions about the new housing envelope, for example. Hence, the decision to go with a hybrid of Corbond and Icynene in our home.

Since none of the other prgrams in the reach of a homeowner do heat gain as well (IIRC), that made HVAC-Calc my default choice. It also allowed me to try out several scenarios, like having three 2-ton air handlers instead of two. I'm happy with my investment.