Honestly because I don't like a heat pump. I had a heat pump at my old house thinking that it would be great and I really wish I hadn't done that afterwards. I don't like that the heat isn't really hot and never really felt that comfortable after doing that system so didn't want to do that again and DH felt the same way - actually more so than me, but I tried to like it since I'd spent the money and convinced him it was the way to go. Honestly I didn't really see much savings from it either. My electrical bills weren't that much lower and in that house I had only electric heat. I'm going to get out with the caulk gun and see what I can find if the temp is ever in a good range around here. I know it is well insulated so air leaks would be the only thing. The problem is the ducts and the placement of the unit. One issue is the flex duct used is also smushed together going over there. Only way to fix that one is to re-route it and thus making it longer. One of the companies that have experience with zoning gave us other options, but no matter what the bedrooms on the other side of the house still will be less in temperature or higher depending on outside temp due to the long run of the ducts. Any suggestions on what you think could be done to improve this then without zoning? Can I just change to a variable speed fan or does it mean the whole unit? I miss having two units as I did with the old house. I also don't like heating/cooling the main parts of the house while sleeping and although in the winter I use a really warm cover and am not bothered by the cold in the master - only the baby's room is bothering me here, in the summer it just feels too warm at night even with ceiling fan on and no covers. The master is very close to the unit so duct length etc. is not the issue there and airleaks doesn't seem to be the issue as I've not detected any drafts in there, but using a candle. Did this when we first moved in due to temp diff. After that they did some air balancing. Do I have any other options in getting the house to be more comfortable and not having to heat/cool areas we don't use? In my old house the main areas weren't heated/cooled during the night as much and the bedrooms weren't during the day. Here we do need to heat/cool the baby's room during the day, but not the master. In the end though I'd just like something that feels comfortable and to not have the main part of the house at 73 so the baby's room and master can be 67. Sorry for the ramblings and the book I wrote. Just getting really frustrated by this and we have moved on to other companies than the one the builder used as we are tired of dealing with the builder and the hvac company and not getting anywhere after 2 years.

Chisue, I'd say 4K is probably not a bad bid. It is more expensive to retrofit than to install originally and it isn't quite as simple as just running some pipe under your existing floor. I don't see that the value of a 5K home in your neighborhood has much of impact on the conversation. From experience, the cost difference in many home retrofits and repairs in a high value RE value area, in the range you mention, and another in a low cost area, is not that much except when transportation costs of materials is at issue. In fact some services and inputs are more expensive in our lower home value area than in our higher value area, simply because more local trades that do higher end type installs are available and competing for work. From our experience we have to often hire someone from the nearby city --45 miles away -- to do the work and that does come at an up charge, understandably. There is also the fact that smaller jobs also cost proportionately more than larger jobs anywhere. It might help if you don't put down the trades as simpletons. If don't like the bid or can't afford that price, why don't you just go hire someone off the streets to install the tubing, direct the job yourself and just ask a master plumber to make a call to hook it up. LOL. Be sure to pull the correct building permit if ine is required -- it often is for additions to mechanical and plumbing systems.

We are finally replacing our 5 ton, 90% efficient Trane system that heats and cools a large part of the main floor in our house. It runs on propane in winter and is 25 years old. The heat exchanger is cracked and we have been advised not to simply replace it. 1. Is it ok to replace the heat exchanger without the rest of the system, considering the age of the other components? We are looking for monthly cost savings also---our electric bill in summer is about $700 per month. The other HVAC system in our home is a 3 ton dual fuel heat pump that is mainly for one wing. Downstairs in the basement level we have a completely separate system, and we have three gas fireplaces, a gas oven and outdoor grill, and one of,our two 80 gal water heaters is gas. The propane bill is insane---it has almost tripled in the past ten years. We are located in rural Georgia. Our temps range from the 20s maybe once or twice a year but around 39-49 for lows in the winter to highs of 97 but around 88-93 in summer. I am thinking that a heat pump would be a better option to replace the 5 ton Trane than a new forced air gas furnace that runs on propane. I have a programmable thermostat that is set for 70 degrees from 6 am to 9 am, 68 from 9 am to 5:30 pm, 69 from 5;30 to 11 pm and 68 degrees overnight, and we have a similar energy saving program for summer, so we are not wasting energy by any means. The secondary main floor system is less than a year old. The area the Trane heats and cools is about 3500 square feet. In total, our heated and cooled space is 5600 square feet. Would anyone recommend staying with the furnace, or is the current thought for changing over to a heat pump? We would invest in a geothermal system but are on a water table and cannot drill down or even horizontally deeper than a few feet. Our long term plan is to put a solar array on one aspect of our roof, and am I correct in thinking a heat pump would take more advantage that electricity than a furnace in winter? I know it would in summer. Thanks in advance for any thoughts, advice, help!

dovetonsils, I could be off on my balance point estimate. Whether it is 35-40, or 20-25 (seems very low for a conventional heat pump), it is going to be dependent on a lot of variables. There are two balance points. One is the point where it is more economical to use the heat pump versus the back up heat system. If the back up is resistance heat, then I agree with you it is towards your range. If you are using propane, then it should be at the higher range. If the cost of propane goes up, then the balance point can be changed. I happen to think we are going through a long period of low natural gas and propane prices, but that is just my opinion. The other balance point is the temperature at which the heat loss of the house is greater than the heat provided by the heat pump. Usually that is higher than the economical cross over, but again it is highly dependent on the specific house and heat pump performance. It seems to me air handlers cost about the same as a furnaces assuming they have similar features. Even if the furnace is a little more expensive, the OP will come out ahead if the difference is less than the additional required electrical work. The furnace blower will be used every time the heat pump operates. The part that will be used less often is the gas valve and burner. Not much maintenance to be done. Every 2-3 years should be fine. It will also mean less wear and tear on the heat pump. The other nice thing about having the furnace is that if the heat pump fails, you can heat the house with no problem while you wait for service. It is no fun servicing a heat pump in the middle of a winter storm. I think the OP should get quotes for both options as part of the decision making process. Either option is viable and will work.