Undersized duct and filter drop. Not getting 3.5 ton of cooling, might be closer to 2.5. Serious duct improvements need consideration. 3 ton may avoid this need.
Since duct is undersized, (more so now that its been sealed) there is a severe energy cost penalty. Imagine MPG if driving your car with emergency brake 1/2 way on.
No. Equipment shutting off when beyond worst case temperatures means oversized. Ideally equipment never shuts off during meat of season load conditions.
Sounds like 3 ton 2 stage communicating will get you there. Comfort, noise, and cost savings will be very gratifying.
I think about now you are feeling overwhelmed, and looking for excuses to do nothing.
I think equipment will be more expensive in 2 years, if you wait the replacement won't conveniently occur when significant mfr incentives are available.
I think there will be less in your 401k, not more.
You'll regret these things, and the $4-800 in energy savings you WONT have. That's what I think.
Because your neighbors are doing it, it must be correct? I hope you didn't think about that before posting.
As I said in an earlier post, I'd like to discuss with my potential contractors the possibility of going with a 3 ton XL20i. Can't you tell I don't have my mind made up yet? So much to consider and I'm trying to learn... let the buyer beware has been my motto for half a century... I don't trust half of what people tell me when they're trying to get my money.
Don't know how to verify the adquacy of the ductwork without help. So far, my "help" says the ducts are OK.
Looking for excuses? No, I don't think so. More like weighing and deciding between my options.
More expensive in 2 years? Probably.
Mfg rebates not coinciding with delayed replacement? Could be, but I do have a home warranty to patch the system until the time is right.
My 401k will lose over the next two years? Possible, but I'm an optimist and look forward to better times ahead.
Regrets? I've had a few, but I'll get over it. Thanks for telling me what you think. I DO appreciate it!
Keep in mind contractors tend to oversize to be "safe" in the event of a non perfect install. Larger equipment is cheaper than installing it correctly, fixing ductwork, and fixing the house. Energy bills are of little concern to the installing contractor, they just want to not get callbacks...
You have already see the result of fixing the house and at least partially correcting the system. Think what would happen if it was installed RIGHT and the house was fixed a bit more. 2.5 tons might even be enough if installed optimally and the house was fixed.
You have a 20X20 return grille, if its a filter return grille, its good for about 1.5 tons of cooling at a velocity of around 380 to 400FPM. So since your return grille is under sized. Why trust that your duct work in the attic is anywhere close to being adequate. those that said its ok, may only be looking at its outer appearance, and not its size for air flow.
I like the XL20i, and have been considering the 4 ton, since it would run at 2 ton most of the time and only cycle up to 4 ton occasionally. In considering the 3 ton, I'm wondering if the 1.5 ton 1st stage would get me the desired comfort without having to run in 3 ton mode most of the time and costing me more in electric. After all, if it runs as a 3 ton most of the time, I'd be $ ahead by buying a 3 ton single compressor model, wouldn't I?
How does one get a proper air flow evaluation?
the only way to know if your ductwork is OK is to measure it's dimensions, lay out all the fittings on paper, and evaluate the layout for CFM, Distribution and air Speed. also, the ductwork needs to be in the correct position, and the proper registers for throw and distribution in the rooms. was a blower door test done on the ductwork for leakage? if not, then it's doubtful the ductwork is "OK"...
in the 80's it was rare to seal any fittings to the plenum, and rare to seal the take offs to the registers.
here's a test for you.
pull any register off the wall, and look into the duct. is there any sealant on the ductwork? if not your ductwork is inadequate for your house by today's standards of energy efficiency, unless ALL your ductwork is inside the house. nothing in the attic, nothing in the crawlspace.
If it were me I'd go 3 ton single stage and fix the ductwork. Also, if your current system is working properly I wouldn't replace it just for energy savings. Investigate fixing the ductwork with your current system and see if it's practical.
You need to find a company that knows how to check ESP/TESP. And then know how to remediate your duct work for better performance.Not something easy to find I know.