I'm doing a full gut remodel of my house in the desert Southwest, and have decided to make a foray into hydronics, for a few reasons (all HVAC contractors in my area are too busy to talk to me, I'd prefer to avoid losing the space a ducted system would eat up, and hot water heat seems, well, cool!)
In brief, I'm beefing up the insulation of the house significantly (to around r-30 in the walls) I have a basement (insulated) that has lots of room for utility chases and pipes. My floorplan is rectangular, about 23'x55', so not a big house or complicated layout. I had a heat loss calc done by an engineer and so I have numbers for each room of the house. Total load is about 36k BTU, 19k on ground level and 17k in the basement. I plan to have one zone for the basement and one for the ground level.
There is a local contractor who I'm occasionally able to ask questions of if I catch him at 8am with a box of donuts or something. He has advised me to basically install a series loop system, with 1/2" pex, using milti/pak 80 slant fin baseboards and a Weil-McLane aquabalance 80 boiler. I did a basic pump head calc using Taco's "Radiant Made Easy" guide and arrived at something like an 003 or 006, to which the contractor said, "Just use a 007, they're cheaper and will work."
I've been doing a lot of reading (Pumping Away, and lots of thread browsing on these forums, the manual of the boiler I want to use) and I'm a bit confused as to whether or not a series loop is a dumb idea. I'm guessing it was recommended to me by Local Contractor guy because it's simple and will work well enough, which I'm all for. I just want to be reasonably sure I'm not making a huge mistake before buying a bunch of equipment.
I have also read a bit on here and in Dan Holohan's books about diverter tee systems and reverse-return systems, which seem more efficient. My basement has a central supporting wall with an i-beam at the top running the length of the house, I could see running the main supply and return along a chase there and running the easy way through my joist bays to each baseboard, above or below.
Am I in way over my head? Am I on the right track? Should I even be considering a more complex 2 pipe system with my limited experience?