More investigation on our ductwork

I have been trying to investigate what the best approach is for addressing our low airflow duct issue in all of our upstairs bedrooms. I contacted an HVAC guy, who is more of a ductwork installer, to come and look at the problem. Naturally, his recommendation was just ductwork related! Shannon over at http://www.house-improvements.com/ also feels that it will improve things, and I trust his advice.

I know that it will. But, will that be the best bang for the buck? I'm not sure. Are there other options that HVAC specialists might know about? I'm not sure also. So, before I call in more contractors, I thought I'd try to use the collective brains of the internet for this one. So I setup an account at http://hvac-talk.com/.

http://hvac-talk.com/ is a site for HVAC professionals to chit chat with, and they also help out homeowners with questions. It's also very active for an HVAC site, so I thought that I might get some responses fairly quickly. And already I did. Essentially, the HVAC pros need more information. So I provided more information to them at http://hvac-talk.com/vbb/showthread.php?1402171-Should-I-address-this-ductwork.

Shophound agreed with Shannon and Larry, the ductwork specialist who came and looked at the issue. Shophound said "that duct configuration would be an airflow killer in ANY installation. Especially at the 90° elbow with no turning vanes and a poor radius on the inside corner. Some folks forget that moving air has momentum: that is one contributor to turbulence within a duct. Within that elbow I can visualize all manner of turbulence as air exiting the transition must suddenly change direction."

Udarrell said "That duct configuration is an absolute nightmare airflow killer..."

Good! So far, the pros are in agreement, the ductwork is a terrible design.

Wahoo suggested that more information is needed. So, I provided more information to him. For reference, I'm including what I provided to him below:

Our furnace is a high efficiency furnace. Manufacture date was Oct 2011. It looks like an "International Comfort Products" model number G9MVT0801716A1. I don't know anything about furnaces, but it says:
- Input BTU/HR HI = 80,000, LO = 52,000
- Ouput BTU/HR HI = 78000, LO = 50,000

Air filter - using a passive filter, 20x25x5", manufacturer is Duststop. Just installed it about 1 1/2 months ago.

Our house is a 2,300 sq ft above grade. Basement is about 700sq ft at 7' height, then about another 700sq ft at 3 1/2' height (in the crawlspace area). The furnace is installed in the bungalow of our split level. The bungalow side of the house above grade is about 700 sq ft. The 2 level side of the house is the other 1,600 sq ft above grade.

The furnace has 2 main runs leaving it. The ductwork to the bungalow area of the house is 12 x 8". The ductwork to the 2 level side of the house, that goes through the concrete block, is 16 x 8".

Here are pictures to help with the research: