For upstate SC, I would also forget about the propane and go all electric. I would also get a competitive quote from a certified electric contractor about electric service upgrade. New Heat Pump System Here is my general spec sheet for new system. both outside and inside units should be replaced to have a properly matched system. 15 SEER, 12.5+ EER, 9 HSPF best matching VS air handler full BTUs in both cooling and heating for your rated size R-410a refrigerant(same as Puron) scroll compressor preferred electronic demand defrost preferred thermostat with "dehumidify on demand" feature staged backup heat strips new and correctly sized refrigerant lineset 10 yr warranty on parts and compressor you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc. any hot/cold spot issues in your home should be addressed. My personal recommendation is Trane/AmStd, Rudd/Rheem, and Carrier/Bryant. Depending on your location, I would not purchase a new system that did not have electronic demand defrost. IMO

1)not a good idea, won't apply to you 2)won't apply to you 3)won't apply to you 4)not a good idea, not sure how they would determine what is too long, shouldn't apply in new system 5)I'm not sure what they are talking about 6)not a good idea, won't apply to you 7)I don't know why they don't want soffits, soffits are often part of a retrofit installation but won't apply to you 8)this I don't understand. ductless systems are a good solution to a retrofit. that said it won't apply to you

Klem1 the duct booster fans are mid range, would be expensive but I get contractor discount @ supply house. the 6" is smaller, we installed it today. the 8" you could hear downstairs...the 6"..not until you are in the room where the supply with the duct booster is located on the other side (small kneewall attic) of the wall. ducts are all hard pipe. two supplies in the room...with duct located inside small foam encapsulated attic @ rear of this room. the return is in the middle room where the heating system closet is located. furnace is in closet, supply plenum penetrates into another foam sealed attic, return is below furnace under heating platform. no supply or return restrictions... I would never ever use a stud bay as supply or return. too much leakage. there is no heat gain from attics...as they are all foam insulated on roofline. that said..when we got on the job this morning.. I took temps of all three rooms, playroom was 4 degrees warmer. on & off during the morning...it held the same temp difference. by lunch the 6" booster fan was installed. we turned the unit on...and took an hour and a half lunch. when we got back...temps were within a degree of each room. homeowners will be back tonight and will keep me informed as to if this holds true for a longer period of time. countrybomo...good to know. I've always been against these fans, mostly because people add a booster fan to a 30' run of flex. but in this house to just even out temps...I"m hoping it will hold within a degree or two of the other rooms. this has been a growing project. you'd love it countrybo... started out just sealing ducts, supply boxes & heating closets. my signature seal of returns..caulked, then ductboard on walls & floors of return...and mastic seal of ductboard. caulking platform to seal heating closet from return... we had to cut access to the attics...between dormers.. and supply plenum of upstairs unit. once I got into the small attic with supply plenum there was an ugly 30+ year install problem. the top of the supply was held on by 4 pieces of duct tape. the top cap had 2 supply ducts taken off ...the ones for the hot upstairs room btw.. the hard pipe duct was 1" away from the plenum with tabs bent over to put a screw or two in to keep the duct somewhat attached to plenum. I could put my hand inside the top to side of the plenum.. and at each duct take off...2 fingers gap all the way around. inside was the worst buildup of mold that I have seen in 15 years. gross stuff. I spend a morning inside the plenum after pulling the insulation out, scraping fg & old glue off the inside of the plenum. getting in & out of the plenum was almost as much fun as squatting on the coil to scrape the plenum...LOL! thought I'd cut myself in half! once the inside of the plenum was clean...I painted mastic inside the plenum to encapsulate any fg particles & glue residue. then we unwrapped each hard pipe duct, screwed the pipe to the ells @ boxes..paint mastic again. end of that day. the next morning...I wrapped all ducts with R-8 stapled, taped seams with fsk...and stapled fsk tape. externally insulated all supply boxes & supply plenum with duct wrap. my rough estimate was that 1/3 of the capacity of the unit was lost in the small attic due to the shape of the plenum & supply ducts. returns were also leaky...and the walls with the returns (each system has 2 returns @ bottom of heating closet as they are on corners...1 return in 2 different rooms) the walls were open stud bays above the retrurn air filter grills. so I used ductboard & hardcast 1402 to seal the stud bays..and then replaced the r/a grills. those filters POP when you put them in now. the difference that the 2 days of sealing & insulating made was really noticable today...after system running last night. for the first time it was actually chilly! sadly...the first floor supply had its own major issues. furred down hall way with mold where plenum joined @ coil, and first bend in fur down. had to take out insulation there too and replace with ductboard. luckily it was at an area that I could lay over the coil & scoot into the 8x16" supply duct. this was probably the tightest area I've ever worked in... took me 2 days to do the work & get the plenum reconnected to the coil. the essen drives only caught one section of supply plenum...so these areas had leaked also since day of install...30+ years ago. if there hadn't been 2 of us on the job...I'd probably be stuck inside the supply plenum until the homeowners return! (bet it would make the newspaper!) 2-3 years ago I did some diagnostic testing for the homeowner. blower door tested the house & tested for duct leakage at that time, recommended foam sealing attics, sealing duct system, etc. homeowner is now acting on those recommendations. his mother told me that the july utlilty bill was ...$700. wow. so...I'm estimating cutting that in half. the bulk of the air infiltration was from attics. duct leakage was high. 5.5 tons of air (two ton upstairs, 3.5 ton downstairs) with 825 cfm of duct leakage. I don't see where I seperated the amounts of duct loss per unit in my paperwork...but I know I did...just didn't break it down for the software. how is your attic project comming? keep me informed as to where you are with it. thanks to both of you for your replies.

A couple years back I was experiencing similar problems due to a too-long dryer duct. I thought about a duct booster fan but the dryer also started eating clothes, and just needed to be replaced. I don't remember the brand, but I bought a "long-vent" dryer that instead of being able to use a 60 foot long vent (with each 90 deg turn counting as 10 additional feet) the dryer can handle a 150 foot long vent (again with each 90 deg turn counting as 10 additional feet) It has made all of the difference in the world. You put the clothes in, set it to "optimum dry" come back and the clothes are dry, what an amazing concept. Two minor complaints about the new dryer are: it doesn't match the front-loading washer next to it, and the controls are on a panel at the back of the machine instead of along the front edge, so they are harder to reach. One less minor complaint is you have to make sure that the ducting is securely attached to the back of the dryer or the greater force of its internal fan will blow the duct off and then proceed to fill your house with lint. Another issue is that most appliance salesmen will have no idea what you are talking about if you ask for a "long vent" dryer. You basically have to research the exact model number and make sure they order that exact model. -Bob