I am building a house and trying to get some recommendations on heat load/loss calculation software for the 'do-it-yourselfer'.  I only plan on using it on my own house that we're building and don't want to spend hundreds of $$'s.  Also, it would be great if it was simple enough for a first timer to use but robust enough to not over simplify the necessary calculations.  I'd really like for it to be as accurate as possible.   I've found HVAC-calc which seems pretty straightforward but wondering if there are other better ones out there (for the first timer)...

Any recommendations on good (but hopefully user friendly) software for this?

Lastly, and sorry for my ignorance, is there a difference in the cooling load vs the heating load and if so does the software also calculate this?

Thanks,

HVAC-calc works well and calculates both the heat and cooling loads.

To design systems for supporting either heating or cooling loads you have to at least look up and enter the correct outside design temperature into the tools or you'll end up with a very poor estimate.

An older version of very simple SlantFin's Hydronic Explorer heat load calculator can be downloaded from a link on this page: http://www.pvsullivan.com/Downloads.html

None of the standard tools are designed to accurately adjust for the actual site solar gain or thermal mass of the house, both of which will affect peak heating & cooling requirements. As a general rule-of-thumb (often broken) Manual-J type tools overestimates the real peak loads by at least 15-25%. (The Slantfin tool seems to overshoot by a bit more than that.) To get better accuracy you need better tools that consider 25 year temperature & cloud-cover data for the location, and spend weeks entering the relevant data on the site & structural details.

Don't be afraid to undersize either the heating or cooling equipment by 20-25% from the HVAC-calc or any other simple tool's output, and don't even THINK about oversizing- you'll pay more up front, and every year thereafter until it's early demise from cycling wear. The room-by-room heat loss numbers they spit out are good for getting decent room to room balance in the heating system though, and oversizing radiators/ducts by 25% has no efficiency & maintenance downside the way oversizing the boiler/heat-pump, or whatever does. Oversizing the radiation is GOOD for system efficiency with condensing boilers, but you'd still want to run with the smallest possible unit that supports the (actual, not calculated) design-day load.)

Thanks to both of you.  I appreciate the input.  I'll consider both.  Also, thanks for the suggestions relative to how to interpret results.

Thanks,