Hello tigerdunes, Thank you for your help in identifying the differences between the 2 bids. I would've never known about the refrigerant lines based from my lack of knowledge of this stuff. Yes, these systems are identical. I had intended this so that I can compare "apples to apples". Carrier did provide the AHRI number, but it's not shown on the proposal. Should I insist that the specifics be added to contract before signing? Carrier dealer plan to use Pro thermostat model# T805, how does this thermostat compare to the Carrier Edge thermostat? I did find it curious that neither Bryant nor Carrier included a Bryant/Carrier brand thermostat. The furnace and ductwork is located in the attic space. I did have a conversation with Bryant dealer a while back inquiring R8 and his response was that most houses in my climate zone uses R6 (the impression I got was that R8 would be more than what I'd need), but that he could give me a quote if I really wanted the upgrade (said it's not that much more in cost). So as far as the option of getting all new R6 ductwork to replace the existing R4, I was leaning towards passing on it factoring that both heating and cooling is scarcely used in this house. The winters are pretty mild here (this past winter the heating was only turned on twice for several hours at dawn. During the summers, the A/C gets turned on no more than a total of 10 times for several hours in the late afternoons of the hottest days. I figured if the existing ducts are in good condition, I saw no cost-benefit to upgrade to new ductwork. What do you think? Am I wrong in my rationality? Yes, there is only one return, located in the hallway. I measured the grille to be about 15"x30", actual open area is closer to 13"x28.5". We are thinking enlarging the existing to 20"x30". Will this be large enough for 1200 CFMs? Thank you again for your help!

If you can get a free connection to gas then that should be your fuel for heating. In most parts of the country it is cheaper to heat with gas than a heat pump. If you are curious post your electric and gas rates and we can do some comparisons on heating costs. The first quote does not make sense. If you are going with a gas furnace, then you should not need a new electrical panel. But you will need to run a 120v 15amp line to the attic, but it should not cost $1565. The gas furnace takes the place of the air handler. A gas furnace costs about the same as the equivalent model air handler. But you will have to run a gas line to the attic. So I don't understand why you need to pay an additional $2500 for the gas option. The Bryant quote has incomplete model numbers. The complete number would indicate the size. You also have no model number for the coil, or what filter will be provided. The Rheem quote seems more reasonable. It is difficult to judge how much of the quote is going towards installing duct work. Is the duct work insulated and if so how much insulation. Flexible duct work should be R6 or R8 rated unless your attic is insulated. Any change the equipment and duct work could be installed in the basement? It would be much better than installing in the attic. The sizes in the Rheem quote seem reasonable. It would be best if a load calculation were performed to confirm the sizes since you have no history other than radiant heating. I am glad to see that the Rheem contractor is proposing a 96% efficiency furnace for the attic. Do you go below freezing in the winter? If so heat tape will need to be installed so the condensate does not freeze. The Rheem quote needs the coil model and filter. I suggest getting a 4 inch media filter.

I thought we agreed that we were not going to limit the discussion to the climate of Katy Texas? Well the OP who started this thread made it sound like he lived near me... which would mean using my climate numbers as opposed to somewhere else. I don't service areas outside my climate so why on earth would I entertain this idea of yours? (I offer advice on occasion but that is all it is --- professional advice --- as this is what I do for a living, I don't sit all day in forum board --- I do have a life outside of HVAC, what little it is right now it's still a life...) You again trying to fit HVAC in a confined specific box in which it does not fit. What are the odds that someone will find that information useful? Probably close to 0% if I had to guess. That sounds like a waste of time... I know this seems productive to you so knock yourself out if you want to do that. Exact numbers are not necessary to educate everyone the source of the condensate. Then why not use the 'about 0.8 gallons estimate' and run with it? An air conditioner in my climate can produce upwards of 5 gallons of water an hour. A condensing furnace will not produce that much. An 80% non condensing furnace will produce 0 condensate water. Oh so let's use the AC condensate line for the furnace condensate. Problem solved right? Most likely not. Drain systems are complex especially when you throw in the variable that a condensing furnace imposes. See I've led your hand to this point --- where the concern right now up to this point is how much more condensate a condensing furnace will produce in my climate Katy, Texas versus other less humid climates in which those furnaces are installed typically in a basement. You don't have the over head flood threat you do here in my climate. All of this --- except: there are safeties on that condensing furnace that if you don't do it properly, the furnace will shut off on nuisance trips. So the furnace is not likely to be the cave in threat due to condensation production. They tend to leak water in drips around the furnace while having very erratic operation most often. You don't get these kinds of problems with a 80% non condensing furnace. What a home owner knows versus that of a pro... you think condensate is the only problem you have to contend with. What is your definition of making this actually work? How does the condensing furnace then become the ceiling cave in threat? Changes to the condensate drain system by people who don't know what they are doing. It may be a home owner, land lord or even a technician who doesn't understand the implications of what they are doing. How much water one produces whether here in this climate in Katy, Texas or a less humid climate (in winter) like Chicago / Wisconsin --- the different in condensate production doesn't matter... *IF* the system to get rid of condensate is adequate. This thread was about a young guy presumably in his 20's attempting to install a condensing furnace in a probable high humid climate. That condensing furnace was bought used. Who in their right mind sells a condensing furnace (used) in a probable high humid climate? One that tried to install said furnace and couldn't get it to work. I have an innate ability to read between the lines. I've seen quite a bit of 'Tom Foolery' in my nearly 26 years of doing this for a living. We can't get it to work so we'll take it out and sell it to someone else. So what makes the condensate drain system of a condensing furnace adequate? The right way. What is the right way? The opposite of wrong. If you want to learn how to do it: There are trade schools for that. Class dismissed......

The smell is created by bacteria (typically on the coil). I am not a botanist so I can not explain why the smell is only happening later in the day. It may be how you're running it. The smell has been known to be a cause of the 'occupants' of the dwelling. This also plays into the known fact that no two homes are alike. Only a very small percentage of homes suffer from this problem. Studies have been done in which people left structure / smell went away with those people. (It's bacteria that generates the smell. Some people's cooties stink) Assuming this is what it is. If you clean the coil and the smell doesn't go away for a time: It's not DSS. condensate water is waste water: it never looks pretty. Some say to drink it, I know better.