Too many opinions on replacing my HVAC
I live in New Jersey and am replacing the entire HVAC system in my
18 year old house. It currently has two furnaces/AC units - one in the
attic for the second floor and one in the basement for the first floor,
AC compressors outside of course. I have received 3 bids and unfortunately
different information on what I need. I will be moving to units that use
R410a from R22 for the AC. Here are them main issues
1. One guy says I don't need to replace the line sets, the other two
2. One guy recommends a 95 furnace in the attic, the other two say
stick with an 80
3. Two guys are willing to go 15+ on the SEER for the AC, the other
guy is not sure my ductwork can handle it and there will be too
much condensation along the ducts in the basement
4. One guy is telling me that Trane is having problems with their 410a
units (he's marketing Lennox now, even though he sold my neighbor an
R22 Trane last year), the other two say not so much
Any help out there would be appreciated -dave
Originally Posted by davenj
Your heat gain for the second floor will not justify a 90+ for the attic + you do not want condensate water in the attic. The units generate alot of water in heating. If you set the thermostst back you will freeze the attic furnace if the attic gets below 32 degrees. I would absolutely go variable speed multi stage 15 + seer if you use the a/c often as it will pay pack in a few years.
The first guy sounds like a straight shooter and knows what he is doing, I bet he owns the company.
Aire Serv of SW Connecticut- Gas heat, dual fuel and central a/c systems installed and serviced
1. We like to change if possible. If not, be sure they are clean and the right size.
2. Too great of a risk of freezing.
3. Size of ductwork doesn't affect SEER, it affects size of A/C. Also condensation doesn't happen from SEER, it happens from cold air in ducts and humid air outside of ducts. Bunch of horsehockey on this one.
4. Pure horsehockey here!
Most brands require variable speed indoor unit to get 15 SEER. So won't pay to put high SEER outdoor unit on standard blower. You gain little in SEER. Don't get carried away. High efficiency is nice but often payback is a lot faster putting the extra money into windows or insulation and you are more comfy that way too.
You can reuse the existing line set.
Prefer not to install 90s in the attic.
Undersized, and poorly insulated duct effects any SEER A/C.
More like HE is having trouble following instructions for R410A.
Thanks so far
Thanks for all the info so far. My listing of who gave me what information
was not all that clear. So here it is
Number one - salesman for larger plumbing & heating co.
He was for replacing line sets, 80 in the upstairs
and was saying that Trane was having issues with 410a
although they do Trane he was pushing Lennox
Number two - salesman for another large plumbing & heating co.
Use existing line sets, 80 or 95 in the attic, just make sure they
are properly serviced, either a 14 or 15 SEER for the AC,
either Trane or Lennox worked for him
Number three - the installation/repair guy that I have been using on
my system for the last 4 or 5 years
Replace line sets, an 80 in the attic, 13 SEER A/C (thought
there might/would be too much condensation along the basement
ductwork if I went up in SEER, He does American Standard (which
I guess is Trane by another name)
While replacing these systems was on my list of things to do, the
downstairs conked out last week in the 95+ heat wave we had
and seems to be down for the count. One of the other things
I am trying to "solve" is that I have a room over the garage
which is you guessed too warm in the summer and too cold in the
winter. The two sales reps said this would be improved with the
Thanks again for all the information -dave
Your room over teh garage won't be much, if any better with a new unit.
Your ductwork would need some alterations to make that room better.
The room over the garage may get a little more air with a variable speed furnace,but notlikly to correct the problem.
The problem is likely undersized ducts ,lack of insulation,or floor trusses of the room are open to the attic on one or more sides,the second two you could take a look at,the duct size you could detail here for an opinion,better to call a Pro.
your linesets will be fine if they are flushed and pressure tested. 15 seer is probably overkill in new jersey, but i don't live there so take that for what its worth. i can't imagine needing a 90% furnace upstairs especially if you are putting one downstairs. trane's 410a systems are just fine down here,but they are coming out with a new line of 15 seers.
"When the people find they can vote themselves money,that will herald the end of the republic" - Benjamin Franklin
"Government is not reason, it is not eloquence, it is force;like fire, a troublesome servant and a fearful master. Never for a moment should it be left to irresponsible action"- George Washington
The rooms over the garage are often never all that comfortable. Think of it as going outside on a cold day with a down vest and a short sleeve shirt. Your core is warm and your arms are cold. I would recommend a heat pump for heating and cooling your home (the core) and a seperate ductless split heat pump for either giving increased cooling or heating for the room over the garage. Mitsubishi Mr. Slims are great for this.
Originally Posted by davenj