Homeowner use of HVAC-Calc

[L West]

Can I, a homeowner with only basic knowledge of HVAC systems and design, use HVAC-Calc to do load calculations and determine overall unit size and duct requirements for my home?

I recently purchased a two year old home and the HVAC system is either undersized or the duct design is inadaquate. I had the system examined by several contractors (none of which did any load calculations) and each has thier own fix. One says replace the 3-1/2 ton unit with a 5 ton, another says the spider duct design needs to be replaced with a trunkline and ths list goes on.

My thoughts are to use the HVAC-Calc and comapre the results to the existing system to determine what changes need to be made.

Thoughts.... suggestions???

[Blake]

I purchased the $39 version last week. I am building a house in El Paso, TX and appropriate air conditioning is critical. I was having the same problems with the builder and the HVAC contractor in giving me accurate answers. If you are willing to take the time to use the software correctly it will be a worthwhile investment.

[Maddog]

Without a doubt, HVAC-Calc is the best load calculation program I've ever used. But, and this is an important but, a homeowner doesn't have as much experience with the variables involved as a GOOD contractor. It's doubtful the load calc run by the homeowner will be as accurate as the one done by the contractor. By all means, get the program, but if you get a differing opinion from a contractor, don't immediately assume you're right and they're wrong-ask them how they came up with their numbers. Maybe you left something out that they didn't.

[KAC40]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Blake:
I purchased the $39 version last week. I am building a house in El Paso, TX and appropriate air conditioning is critical. I was having the same problems with the builder and the HVAC contractor in giving me accurate answers. If you are willing to take the time to use the software correctly it will be a worthwhile investment.<HR></BLOCKQUOTE>I would tend to trust the contractor. That is how he makes his living. Have'nt met a builder yet that knows jack about HVAC. See if your load calc. and the contractors comes close and let us know.

[L West]

Thanks everyone for your input. The problem I have with trusting contractors is that each proposal is very different. One says it is a duct probelm another says I need larger equipment, etc, etc. The price spectrum ranges from $1,200 to $11,000! Money is not the main issue but I don't want to waste money trying one fix after another if the software can help me determine the root cause. I'll get the software and give it a try. If nothing else it will be educational. Thanks again.

[psychoanalyst]

Think about this. Competition drives the market into making a cheaper product..you know things just aren't built the way they used to be.

Contractors are the same way. We don't want to lower our standards but if that is what it takes to be profitable then that is what we will do. It's just business.