Oil Boiler -) NG + new AC
My wife and I have had enough of our 45 year old but mostly functional oil boiler (heat and DHW) and window air conditioners. We have cast iron baseboard heating elements that are in decent shape and we have recently replaced all windows with new good qualtiy Pella windows. We have no duct work and no natural gas hookup at this time. But I was able to confirm that we CAN get NG install at our house. We knew it would be an expensive undertaking but decide it was worth the cost to us especially with high oil prices and our poor DHW production in the winter.
I had 3 companies do estimates for a solution to get off oil for heating and install central air. We left the design options open (forced air vs hot water, gas vs. geo, etc). All 3 companies suggested that we stick with hot water heating with a ModCon NG boiler and then install seperate AC with new duct work. The duct work is a bit tricky in some spots (part of the house is on slab with rooms above) but do-able especially if only for AC. Eventually, all 3 concluded on the same basic duct design paths.
Only one company actually did a Manual J load calc and they even provided me the full report. After researching more and more, they seem to be doing and saying all of the right things. Not suprisingly, they are the more expensive of the 2 quotes that I have received. They seem to be the winner. They provided 2 options for heating and 2 for cooling. So, what I am hoping for is:
1) Opinions on if the overall design plan sounds right
2) Which equipment options you would choose. Specifically, is the additional cost of the more expensive units are worth it. I have read that a 2-stage AC unit may provide a more comfortable experience and that higher SEER will cost less to run. But the additional cost seems high and I don't think the cost may be worth it (at least for just a higher SEER rating).
Split-level/2 Story house (2 levels on one side of the house)
Near Philadelphia, PA
1519 sq ft room area (measured)
Heating Load - 46,962 Btuh
Cooling Load - 25,771 Btuh / 2.481 Tons (based on 77% sensible capacity)
(many other details in the Manual J report)
Currently single zone oil boiler system. Quotes are to make it 3 zones including all hardware/plumbing. Also includes running NG lines to install area
1) 95% AFUE Triangle Tube PE110 Combi-Boiler w/ zoning system - $13,699
2) 90% AFUE Navien CH240 Combi-Boiler w/ zoning system - $11,499
Both appear to modulate to low enough to not be oversized for my load. Both would do DHW internally.
Include duct work, electrical all other stuff needed with a brand new install
1) Carrier 3 ton Infinity 21 Model 24ANA136 2 Stage AC, Infinity Model FE4ANF002 Air Handler, Infinity Control - $12,999
2) Carrier 2.5 ton Comfort 16 Model 24ACC630 1 Stage AC, Performance Model FV4CNF002 Air Handler, Edge Termidistat Control - $11,399
All have rebate options from my electric company be they are same no matter which I pick. Since I used the tax credit for my new windows in the last 2 years, my understanding is that I am not eligible for any further federal tax credits.
Your opinions or comments would be very much appreicated!