...and just as I thought, it comes out to 2.5 tons if I change nothing about the place.
I had this plan in mind to put in a 2.5 ton Trane XL19i, split the place into 2 zones, Therma-Stor Ultra-Air unit, etc.

The only thing is, I planed on having R-38 insulation blown in, using R-8 insulation on the new duct system, replacing my single pane metal windows with double pane inert gas filled vynal frame low E windows, replacing 2 sliding glass doors with french doors, installing a storm door at the entry and sealing the building envelop as tight as I can.

Redid the load calc and if I do all that, my 1100 sq ft duplex will only have an 10,000 BTU sensable load on a 100 degree day with a 75 degree indoor temperature and 50% RH.

So much for my plans for a fancy high tech HVAC system!

Considdering I'll be doing everything but blowing in the insulation myself, what do you think would be less expensive over a 10 year period?

A) Doing all of the work on the house to make it efficient as possible and installing a 1 ton Trane XB10 heat pump with a standard air handler (varriable speed air handler with this outdoor unit has something like a 90/10 sensable/latent ratio, so is a no go)


B) Don't use as fancy of windows, blow in less insulation, be less picky about sealing up the building envelop and installing a 2 ton Trane XL16i heat pump with varriable speed air handler.

HVAC equipment for A or B would cost me below normal wholesale since it is for my own house.
Cost of IAQ equipment would be the same regardless.
Option B would be less work for me.
Option B would have a 10 year parts and labor warranty, so if anything broke, I would be getting paid to work on my own system.
I don't think there would be a significant difference in utilities.

Hmmm, seems I have talked myself into option B while I was typing this!

[Edited by mark beiser on 02-08-2005 at 08:07 PM]