I would like to add central air to my house and of course I will be doing most of it my self ( retired ) and just a little short of the 20K to 30K estimates I got for professional install. I have done this once before on a smaller house but that one had pre existing duct work, this one doesn't (boiler heat). I have worked out where all the duct work can go and how to route it but not the sizing of the ducts or the tonnage thats where BEopt comes in. It's free and seems pretty deep. Any opinons? Tom

BEopt is a more precise energy prediction tool than Manual-J for tonnage/sizing issues, but SFAIK doesn't have any duct-design features. (Does it? It's been awhile since I played with it- haven't even come close to twiddling with every part.)

BEopt is an excellent tool for sizing heating and cooling systems, but it is really intended as an optimization tool for doing tradeoffs in building design versus cost and energy useage, i.e., the most cost effective approaches to reach a desired energy usage, or the best financial payback. However, according to a Webinar held yesterday on the latest version (BEopt 2.0), it does not have any duct design capability. Some users have requested that capability, but it is not there yet.

I have played with BeOpt as well as HEED from UCLA. They agree pretty closely on BU needs. But they don't offer duct design functions. Have you considered a mini-split or 2? Depending on room size and location I think you can do a lot better than 20,000 especially if have have skills to install, then get certified person to charge and inspect it.

You might consider purchasing this piece of software at www.hvaccalc.com . The resulting room load calcs you obtain from BEopt could be plugged in to obtain the duct sizing. You could also use this program to get a second opinion on load calcs although BEopt is probably more sophisticated in that regard. This program is pretty easy to use and a good value for the price in my opinion.

i.e., the most cost effective approaches to reach a desired energy usage, or the best financial payback.

I'll argue that this is almost always appropriate and tools that don't do this are cumbersome to use.

Posted By jonr on 28 Apr 2013 01:49 PM

i.e., the most cost effective approaches to reach a desired energy usage, or the best financial payback.

I'll argue that this is almost always appropriate and tools that don't do this are cumbersome to use.

Let us be specific on what BEopt has to offer, which I think is fairly unique.  With most energy analysis software, the user can describe the candidate structure, and the software will provide the estimated energy usage.  The user can then rerun the software with various levels of insulation and windows, for example, and make up a matrix of building options and energy usage.  The user can then look up and assign prices to each of the options, and make a decision about what looks attractive.

In contrast, BEopt automates much of this process.  The user can highlight a range of options for insulation levels, window types, etc., and BEopt will run many variations of the different levels of insulation for walls, ceiling, etc. with different window option, with all results in a batch file.  (An optimization tool is used to limit the input iterations to cases that look attractive.)  Further BEopt has price estimates for each of these options, and will make a graph of Annualized Energy Related Costs ($/yr) versus Source Energy Savings (%/yr), plotting each option on the graph that will describe a curve showing the minimum value for the Annualized Energy Related Costs, so this is the optimum for financial payback.  Somewhere beyond this point, if further energy reductions are desired, for net-zero source energy, for example, BEopt has prices for solar PV systems and will show the best financial payback for where to quit adding more insulation and start adding a PV system instead.  I think these are fairly interesting and unique capabilities for BEopt. 

It is almost trivial to say that some will complain about the pricing used in BEopt, and that they would rather use their own pricing.  BEopt even allows access to the libraries used to change pricing, add new components, etc.  It is very flexible. 

What other software is available with these capabilities, jonr? 

What other software is available with these capabilities, jonr?

Given that I think that BEopt allows the better approach, I haven't looked.

So the answer to OPs question is "no".

Besides freeware, HVAC calc can be purchased with a one time license that makes it fairly inexpensive to get a man J load. The "duct design" capability of HVAC calc is not perfect, but it will get your trunks the right size if you offer the proper info.

The answer is Wrightsoft. But I don't know of any relevant software that one can learn independently and produce meaningful data for use in real-world installations of HVAC equipment. OK, maybe Dana. Still, a steep learning curve without some CAD training and then there is the practical experience, likely maintenance, balancing tools and skills to go along. A little professional design help would go a long way. True for the majority of professional installers as well.