Single Stage Goodman Furnace - Two Stage Bryant AC???
Hi, everyone.. totally new to AC and shopping to put it in my first house. Read a decent amount on this forum, people seem very knowledgeable so I thought I'd post a couple questions.
1) I've shopped quotes for Lennox, Trane and Bryant. I liked the company that deals Bryant. They have great reviews, A+ Better Business Bureau rating and they also seemed to have the best pricing.
2) My house is about 2250 sqft in the north east and I am looking at 3 Ton units. After asking a lot of questions, going through a lot of manuals etc. the two units I'm looking at are the Bryant 126B (single stage) and the 127A (two stage).
3) My furnace is a Goodman GMPN080-4 Rev B. When the last couple installers came for quotes I was looking for a single stage AC unit (didn't consider two stage until I got a pretty good price quote) so they simply looked at the furnace and said it would be no problem. I think my furnace is single stage, and to be honest I don't know how to tell if it's two stage. I tried looking through manuals and I think it's single stage but not sure.
4) The things I want from my AC are obviously to cool the air but I'm also looking for lower humidity and I would like it to be somewhat quiet as it will be next to my deck. I spent a lot of time looking at dB ratings. I live in the northeast but I'm originally from northern Ontario, Canada. I find 80-85 degrees hot so I think I will use AC more than most in my area.
My question arises because the Bryant guy I have been talking to told me that either system would be great. The two stage 127A has a fairly similar price to the 126B and I thought it might be worth the extra money. I've read all about the lower humidity with a two stage unit, cost to run, low noise etc. etc.
I asked him about the two stage working on my furnace that we both thought was single stage (He's now coming back to look at it and is looking up the model number I listed above) and he said that shouldn't be an issue. I asked him a little more about it and he told me he was going to look into it more for me.
Will the two stage 127A be a problem? Should I go with the 126B or another single stage? I also looked at the Lennox XC14 and XC17 because of their low noise ratings (around 70dB) but liked the Bryant models as well. Bryant were also a better deal.
Thanks for reading all that... Any input from you guys would be appreciated!
To make a 2 stage A/C work to its full potential, it should be matched to a variable-speed motor. The (gas) staging of the furnace is irrelevant. It's the blower motor that needs to change speeds to the match the staging of the the A/C.
I prefer Lennox... the reality is all units work well if installed properly.... and maintained
it was working.... played with it.... now its broke.... whats the going hourly rate for HVAC repair
George, thanks for the response!
You bring up something I knew nothing about... I thought the blower motor and furnace stage was the same thing. I'm assuming it's not?
This may be a really dumb question.. but can I have a single stage furnace with a variable stage blower? And if I did that would it be fine with two stage A/C?
What will be the outcome if I pair the 2 stage AC unit with a blower that isn't variable speed? Slight performance drop or some major issues?
New furnaces with VS motors are always 2-stage or modulating. With relays and a lot of know how, the PSC motor in your furnace can be made to run at different speed in conjunction to the 2-stage A/C. You don't lose efficiency with the motor in your furnace, but you'll not get the benefits of the 2-stage A/C. With a VS motor, you will gain efficiency. What style of home do you have? Ranch or 2-story?
Originally Posted by js66
House is about 12 years old, two story, furnace is in a finished basement. I'm assuming the furnace is around 12 years old as well.
Your GMPN is a single stage furnace. The blower in it can't be slowed down enough for good moisture removal.
With anything over about 14 SEER, you are paying for efficiency you won't get. To get the SEER the 126 and 127 CAN do, you need a matched Bryant indoor unit with high efficiency blower motor.
In many parts of the country, especially the NE with mild summers, high SEER has little economic payback. You should put the bucks into insulation or something that will really save you some money. If you want quiet, look for a 13 or 14 SEER unit with a low sound rating number. New American Standard/Trane 13 SEER units with scroll compressors, XR13 for example, now have a 71db rating at 3 ton where with the old recip it was much higher.
I bet a 2.5 ton A/C would work just fine. Better dehumidification, more efficient running times (not the start and stop of the 3 ton) and less money to buy. Just a thought.
Originally Posted by js66
Listening to the a/c adds about multispeeding a/c controlling %RH, you would think they really do provide perfect %RH. I have tested many, but yet to find one that will maintain <50%RH during low/no cooling loads. They are a little better, but without significant cooling loads and overcooling, they will not maintain <50%RH throughout your home.
I suggest a basic 13-14 SEER a/c and a small whole house dehumidifier to maintain <50%RH even with the a/c off. Checkout the Ultra-Aire 70H. You can use the whole house for a controlled small amount of fresh air ventilation which is also much needed during the calm weather.
Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
Use +Merv 10 air filter. -Don't forget the "Golden Rule"
FWIM, most MFG's do make a single stage furnace with an X-13 ECM. I figure these units are best suited for southern climates and dual fuel where you want a higher seer rating but don't care about a 2 stage gas valve.
Originally Posted by George2
Thanks for all of the great information guys. I really appreciate it. This is a very knowledgeable board!
My issue seems to be I don't need high SEER ratings, but it seems the quieter units are the higher SEER units. I originally started out looking at 13 SEER units but then there was only a small price bump to the 16 SEER 126B. Then another small bump to the 127A. I know you can't mention price here so I won't but it was a fairly small difference with a lare difference in dB rating. I will say my Bryant dealer was one of the few that only had a small bump from 13 to 16 SEER. Most were a decent amount more. From what I understand there is also a $300 tax credit for anything over 16 SEER. That makes the difference in price very small. To be honest for me it's more about comfort and low noise, I won't pay a ton for that, but I will pay a bit more.
I called Bryant directly and they sent me a lot of literature about the 126B and 127A. The 126B looks to be 72dB for a 3 Ton unit. The 127A is 73 dB low and 74 dB high. When I look on the Trane website and compare the XR13 and XL15i they come in at 76 dB and 74 dB. Maybe their website isn't up to date? I don't know but Trane seemed to have more noise.
I would love to get the two stage 127A (a small bump in price from the 126B) but it looks like I have a single stage furnace. Let me ask you guys this...
Will the 127A just not work 100% effectively with my furnace? Is this something I shouldn't even consider? I ask because at some point I will need a new furnace. If I bought a new furnace I'm assuming it would be two stage. I hope my furnace is good for a while... but I would hate to buy the single stage AC and then need a furnace in 3-4 years, buy the two stage furnace and have a single stage AC unit that is only 3-4 years old which I couldn't justify replacing to two stage.
A lot of headaches in this business, kudos to all of you helping us out!
A 2 stage A/C on a PSC blower doesn't do well at dehumidifying in first stage. As the blower doesn't slow down enough. Sometimes, they will do worse at removing moisture in first stage.
A single stage A/C on a VS blower works far far better, then a 2 stage A/C on a PSC blower.