That is a crazy high gas rate. Do you have a flat fee worked into that? We pay $10 a month flat so if you look at what 1 therm costs, it is $11. But truly the therm costs $1. A NG furnace will always save a few in a dual fuel situation but not enough to make it worth it for you. Where is your MBR? Don't you really just want the MBR at 66 at night? What you probably want is more tonnage which isn't going to work with your existing ductwork most likely. So it is pretty cost prohibitive compared to other options. The other options are to reduce your heat load. Air sealing is cheap enough to do some things DIY - do you have attic stairs? Do you have cans into the attic? Sealing these things may lower your temp enough. Controlling solar gain is really where the real savings is. The cheapest is solar screens but they do effect the transmission of light. Plant trees. If you don't have low SHGC windows this can make a huge difference. Switch to LED lights - anything used over an hour a day is a reasonable payback and it will lower the a/c load. LED is far better than CFLs and we find it acceptable everywhere except the bathroom. We keep our master at 65 at night (and high 50s in the winter) with a ceiling fan so I understand where you are coming from. Since your usage is so high, it would definitely pay to get some high efficiency equipment. But overall, the best answer to a cooler house in the summer is not to change the a/c size but to control the loads. I do feel like your usage is pretty high even given your locale and requirements. I peaked at $150 (probably $90 in a/c) in July this year with a 65 degree bedroom suite for 5000 sqft in NC. Obviously you are warmer but not double.

daffer I think your strategy is right on target. The only question is whether you want dual fuel(var spd furnace backup) or an air handler(with strip heat backup). With an air handler and strip heat, you would need to check electric panel/service to see if you have capacity to handle backup strip heat. If not, cost to upgrade electric service. Here are three best configurations with var speed air handler. I like the numbers of the Carrier Infinity 16 HP with Infinity controller best. It has better BTU numbers both heating and cooling. 552846 Active Systems XP19 SERIES LENNOX INDUSTRIES, INC. XP19-060-230* CBX32MV-068-230* 58500 12.05 16.30 53500 8.25 32800 1481762 Active Systems XL19I WEATHERTRON TRANE 2TWZ9060C1 2TEE3D65A1 56000 9.90 15.75 51000 8.50 31400 1250425 Active Systems INFINITY 16 PURON HP CARRIER AIR CONDITIONING 25HNA660A30 FE4ANB006+UI 60000 11.10 15.30 57500 9.00 34200 You know 5 ton is correct size? I would check Duke Power and see if they offer any rate incentive for HP heating. 410 refrigerant is the way the market is moving. IMO

>> Hope to hear an update from the original poster of the thread soon as well. Hi, still here. :) Yeah, so far, none of the contractors have proposed a 'mismatched' coil and condenser. One said 5/5, but all the others have been 4/4 so far. No load calcs yet. One contractor said he'd do it if there were a commitment to go with them. So if they commit to dropping their price and changing some of the equip to match better proposals from others, then we may have something.. :) [unfortunately, although they had a polished sales presentation, their bid missed a couple elements with regard to equipment, including the low voltage wiring and the mismatched coil size (width)] I did see that the 4-ton XL15i requires the 7/8" x 3/8", so looks like I'm good. (phew) A contractor on Friday also said I'd need additional wiring to hook up a heat pump outside, so looks like it was missed by the one proposal. I think this has been asked before, but is the TL900 the same as the VisionPRO IAQ? I have two more contractors coming Monday, so after that will hopefully have all the information I need to start discussing it further with 1 or 2 and start negotiating equipment and price details. On related topics: There have been other differences in proposals, with some suggesting/including a replacement condenser pad, some not. I currently have what looks like an interlocking plastic condenser pad. Doesn't appear damaged, although may be slightly out-of-level (will be checking to make sure). Surrounded by bushes that I keep in check, and mulched w/ weeding done when needed. I understand concrete is the best option, but doubt the pads being included in some of the bids are much better than what I have. I'll be doing my own check to confirm what I have would fit the new condenser/heat pump. And, some are including an Electrical Disconnect/Fuse rewiring, some not. There's currently a disconnect (no fuse) connected to a 40amp double pole circuit breaker. One guy told me "that should be enough, but if it isn't and it trips a lot, we'll fix it free of charge" or something to the effect; which I'm not sure whether it's a good deal that he's not trying to sell me something I don't need or a caution flag that he doesn't know if it's sufficient.. The XL15i documentation says "Min Cir Ampacity = 30" and "Max Fuse Size (Amps) = 50", so I'm not sure whether that means the 40amp circuit breaker is sufficient or not.

> The generator is powered by propane? Yes. > You need to see what the KW pull is for a heat pump. At the moment with existing setup, what else does your generator power during an outage? Generator powers nearly everything. (The only things not on the generator are the septic enhanced treatment pumps, the pool equipment, and the hot tub.) > Based on your location/climate, a heat pump would be a logical choice for heating versus propane heating. The last few days have been fairly typical for the "cold" part of the year. In the last 72 hours, minimum temp 35, average temp 41. > Can you be a little more specific on how your tiered electric rate works? Without heating or cooling, what is a good average of KWH usage each month for your home? It is the PG&E E-6 rate plan. http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-6.pdf This past month our net usage was 28.4 kWh/day, but during the summer we generate more than we use. > How large is your home? 2400 square feet. > Have you thought of a dual fuel system? Possibly an 80% eff two stg furnace that could be used for those rare cold snaps and power outages?The backup furnace would eliminate the need for aux heat from heat strips. That's what I'm thinking now. Definitely solves the power outage problem, though the woodstove does that nearly as well. Seems like a low or moderate efficiency furnace is about the same price as a standalone air handler anyway. > How would you characterize the insulation qualities of your home? Home was built in 1972, parts remodelled in 1980 or so... so not the greatest insulation, but we have installed double-pane windows everywhere and upgraded the insulation in some areas. > Ductwork has been inspected? Any hot cold spots in your home? Ductwork will be overhauled at the same time we install the new system. No particular hot or cold spots now though.