AL gal needs advice on HVAC

[bamaheat]

Hello and Help HVAV Experts,
I live in Alabama and it gets pretty hot and humid. I am going to have to replace my 25+year old HVAC system in the next several weeks. I have started getting quotes and of course they are all for different brand equipment....which leaves me not really knowing what to do...I just want a dependable unit and one that is easy to repair when needed. Are the low end Carriers, Rheems, Lennox all about the same or is one a better choice than the other? Do you have a brand in mine that is reliable. I need a 3 Ton Compressor, my furnace at this time is 100,000 btus but have been told the one they will put is only 88,000 btus. Should I go with this low of btus?

One quote was for a carrier 24abr336/furnace 58sta090/thermostat tstatccnac01 5 yr parts/labor.

Could someone reply with brand/model numbers that I can specifcally ask quotes on that would be a good unit so I can compare costs from different contractors on the same system?

Any help is appreciated.

[RyanHughes]

Your system is 25 years old, so I'd have them look at your ductwork as it may need some revamping for efficiency and comfort reasons. Did the old 3 ton cool okay? The new furnace will (presumably) be more efficient, hence less input needed. Brand wise you will get a wide range of opinions; I'd put your efforts into finding the best contractor. The Carrier equipment you've been quoted is about as low end as it gets in Carrier's product line. Not necessarily a bad thing, just basic equipment. I wouldn't have that outdoor unit installed (no pressure switch protection, coil not protected very well, noisier than others). Is this what you requested to be quoted? If you can, post the models of the other equipment you've been quoted.

[beenthere]

There is no one best brand or model.

Ask them to do a load calc.

You might only need a 60,000BTU furnace.

[bamaheat]

Thanks for the replies. I know a J calc was done and came out to 31800 or so. So the 3 ton would be right I guess. House is about 1500sqft-1600 with vaulted ceiling in living room. The old unit cooled okay. Yes, please anyone give some units that you would recommend. The lennox only gave me the seer numbers, no model numbers, 13 seer and one for the 16 seer.

I need, from you guys the experts, actual model numbers/brands.. so I can specifically ask for them. Otherwise, Im afraid I am at the mercy of the contractor. Anymore advise is appreciated.
Thanks

[RyanHughes]

Are you looking at top of the line, mid grade, or lower tier? Most brands have multiple levels in their product line. Manufacturer websites (www.lennox.com, www.trane.com, www.carrier.com, etc.) will list the model information you're looking for.

[bamaheat]

Thanks, I will check these sites. I am looking for mid to low level unit.

[beenthere]

What size furnace did the load calc say.

Don't ask for brands or models.
Unless your asking about one you have already received a quote on.
Other wise. You'll get personal opinions.

Just because we like a brand. Doesnt mean that its a good brand for your area.

Worse thng you can do. Is buy a brand. Best thing is to use a contractor you trust.

[sktn77a]

100,000 BTU is a......... "healthy"........ furnace for a 1500sq ft house (even with vaulted ceilings). Check they used the Manual J calculation for the furnace sizing also.

[bamaheat]

beenthere and ryan,
thanks for your responses.
well of course the only contractor who did the calculation took it with him.
lennox #1 option ac 13acx/ furnace g50 .
#2 option ac xc14/ furnace g60v
i cant find btus for these units anywhere nor online.
thanks

[beenthere]

The numbers he gave you only indicate model line.
Not size.

[bamaheat]

thanks beenthere.
well, it's a good thing i have 3 window fans...i know the ac is a 3 ton but i dont know about the furnace in lennox quotes. sorry. another contractor said he would put in 100,000 btu since thats what is here now. i know ive got more homework to do before i shell out my cash.

[bamaheat]

thanks sktn,
i didnt see your post earlier. all i remember is the j cal was for a 3 ton unit. as i stated, ive got some homework to do. i wish i had started in the winter months.

[gasguy]

If the other contractors didn't do a load calc, I would skip them. Installing a new 100K furnace because "that's what the old one was" is NOT the way to determine proper sizing. What if the old one was oversized? How do they know? Make sure they also check the ductwork to see if it is adquate for the new equipment. Often newer stuff requires larger ductwork to get proper air flow and efficiency.

Alot of people assume that if the furnace kept the house warm that "it works fine". Well, maybe not. An oversized furnace will have short run times and cycle on & off more often, and the house will have greater swings is temperature. A smaller (properly sized) furnace will have longer run times, and fewer cycles. This lets the furnace run more efficiently, saves wear and tear from frequent start-ups where most wear/energy use occurs, and improves comfort by minimizing swings in temperature.

As others have stated, don't be too concerned about brand names. Most brands have similar quality equipment within the same price ranges. Proper installation is the most important part of an HVAC system. Spend your time researching the contractors, and when you find one you are comfortable with trust them to select the proper equipment for your needs.

Good luck! :D

[bamaheat]

thanks gasguy,
only one out of the 3 contractors did a j calculation. when i asked about it, one stated the last time he did that was in school and he stated he had been employed since 95 doing hvac. the bad thing is he was the one that seemed more honest. i guess i need to start over in getting quotes.

[catmanacman]

i like option 2 the furnace could be a g60 uhv 070-36 or g60 uhv 090-60 the 090 furnace gets a better seer rating due to the large blower but if you do not need that much heat you trade comfort for seer

[bamaheat]

thanks catmanacman,
i will keep that in mind....i hope to start over in this quest with more knowledge and perhaps post with model numbers soon.

[Twilly]

Twilli met a girl in Alabama back in 1972 Twilli still thinks about her

[Joe Harper]

Twilli, are you my daddy?

[bamaheat]

yall...are funny.

[fenian]

Twilli, are you my daddy?

i hope you look more like your mom

[udarrell]

Amana & Goodman are okay, too.
http://www.goodmanmfg.com/

http://www.amana-hac.com/

Good warranties & service are important.

The main thing is a quality installation->
Your entire home & ductwork are critically important parts of the A/C's total performance.

(AL High Humidity) Excessive air infiltration can be as high as half the cooling load, the ductwork & airflow can tank the BTUH operating performance.
- Click on udarrell for more info.

[ihavenolegs]

if you're in a hot and humid climate you'll find your insulation on the ductwork in the system is just as important as the equipment, make sure you replace that with the unit if it has been 25yrs.

dehumidifiers are nice if you have the cash, better yet a unit that is designed to do so (2 speed systems are the top of the line when it comes to this, and are also the cheapest to run, but the most expensive to purchase as a rule.)

[bamaheat]

thanks ihavenolegs and udarrell,
as someone who researches before pulling the trigger on something, i feel sort of overwhelmed since not any of the contractors went to the attic to look at the duct work. i am hoping they are adequate. i guess the contractors dont really care.

[beenthere]

Keep calling contractors until you find one that cares. Or run out of contractors to call.

[Twilly]

thanks ihavenolegs and udarrell,
as someone who researches before pulling the trigger on something.


Twilli don't spend a lot of time researching.

[Jevans]

Be sure to ask about the Federal Tax Rebate. It's basically 30% off units that meet certian guidelines. You may be able to get a higher seer unit for the same or less $ then a lower rated one. Just be sure to get the ari certificate to prove it meets the guidelines.

[bamaheat]

Thanks jevans and twilli,
one thing, should i insist on new discharge and suction tubing, everyone thats come say they just flush them out since i will go with the new freon deal. would this harm a new unit or warranty?
thank you folks

[udarrell]

Thanks jevans and twilli,
one thing, should i insist on new discharge and suction tubing, everyone thats come say they just flush them out since i will go with the new freon deal. would this harm a new unit or warranty?
thank you folks

I would insist on a complete change-out of the refrigerant lines.

R-22 7/8" pipe is not rated for R-410A use. R-410A runs at a much higher pressure and the wall thickness of R-410A pipe is much thicker. The incompatible Oil is only one of the problems.

Make sure the copper lines meet R-410A Code. - Darrell

[speedytom]

Be sure to ask about the Federal Tax Rebate. It's basically 30% off units that meet certian guidelines. You may be able to get a higher seer unit for the same or less $ then a lower rated one. Just be sure to get the ari certificate to prove it meets the guidelines.

out here in cali the units that qualify are all 2 stage compressor units and variable speed furnaces. these are the most expensive units out there at the moment i believe. BUT they are easily the most efficient. if you are worried about your duct work not being sufficient why not just ask the contractor you have out to look at it. tell them you have done research and ppl are recommending you change it out. see what they say.

[Iceman666]

Passed my 410a safty & training certification last week R22 line sets must be changed for 410a. Unless the system can use 407c.

[beenthere]

Passed my 410a safty & training certification last week R22 line sets must be changed for 410a. Unless the system can use 407c.
That training course wan't put on by a manufacturer, as it.

Check out Carriers instructions.

[RyanHughes]

Passed my 410a safty & training certification last week R22 line sets must be changed for 410a. Unless the system can use 407c.

If that's true it certainly isn't done over half the time. :rolleyes:

[bamaheat]

thanks for your input guys,
it does seem no one wants to replace the lines, except one i ask at my job who does ac. when i decide on a system im going to write in the contract that "contractor refuses to change copper discharge and suction lines and will assume full financial responsibility if manufacturer finds this responsible for any malfunctions"...it seems what should be done isnt the norm....

one question, i do not want to put too much more $$ into my home, as i pray i can move to a smaller home in the next 4-5 years..my furnace seems to work ok, though expensive as it is natural gas...a rudd 100,000input btu and 80,000bonnet which i assume means output btus... this system is a rudd uga 100c probaby made in the late 1970's...should i replace, and if i dont will i be able to find an ac coil to fit ontop of the furnace properly, as i will have to buy a coil and ac outside unit for sure.

thanks to all who have given me insite. this is a great site. i may be learning too much though...like the r410a is at 1.6 times more pressure than the r22 so the copper pipes should be thicker... hence should be changed to r410a regulation pipes....i think i read that on here...

[RyanHughes]

I would insist on a complete change-out of the refrigerant lines.

R-22 7/8" pipe is not rated for R-410A use. R-410A runs at a much higher pressure and the wall thickness of R-410A pipe is much thicker. The incompatible Oil is only one of the problems.

Make sure the copper lines meet R-410A Code. - Darrell

When contractors buy linesets, are the refrigerant types suitable listed? I was under the impression that copper made earlier was thicker than that made and sold today. Can anyone clarify?

While I agree replacing linesets is good measure, those I've talked to never seem to have any issues with reusing them properly and certainly have not reported any problems. I think procedure is key here.

[bamaheat]

ryan,
i really dont know about that...i know the old oils and stuff cant mix with the new freon as it is incompatable...and most are saying they blow out the pipes with a chemical or nitrogen or something..
but if i spend money on a new system...i would like it done right...like they would do their own home....it may be okay, and it certainly seems the norm..if anyone(homeowner) ever knew enough to ask or question this anyway.. just talked to an md today who just got a new unit...he had know idea if they changed out the lines or not for the new freon unit.... if most contractors are doing this, perhaps there isnt any problem with it..

[udarrell]

Well, there use to be 3 classifications of copper tubing; K heavy thick wall; L medium wall thickness & most used for A/C work; M thin walled used for lower pressure water applications & drain lines.

The 7/8ths wall thickness was 0.065"; L was 0.045"; a lot thinner.

Some are saying we need to use K on 7/8ths inch & larger copper tubing? I don't know, who is right, - we need to know.

K is also used where abnormal corrosion could be a problem.

The mfg'ers ought to know if the lines need to be changed for safety or other reasons.

I don't know if any other classifications have been added for the new refrigerant use.

Under unusual conditions the low side could have a lot of pressure on it.

Never blew any lines open with nitrogen & some of us put far more pressure in there, than we were supposed to, for leak detection.

Going forward we need to know exactly what to do. - Darrell

[beenthere]

thanks to all who have given me insite. this is a great site. i may be learning too much though...like the r410a is at 1.6 times more pressure than the r22 so the copper pipes should be thicker... hence should be changed to r410a regulation pipes....i think i read that on here...

In the USA.
Cooper lines aren't made any thicker then they were 20 years ago.

In fact. The new coils that are rated for R410A, are made from thinner copper then your old coil.

[udarrell]

Well using Google Chrome browser & doing research I lost my reply, & had to do it over!

They talk about engineering everything heavier &/or stronger for R410A, then give no data.

This is not going to prove much because it is not USA info.
I couldn't get bact to the search address for the link.

No 7/8" Not listed, only listed up to 3/4"
They recommended 1.22-mm for 3/4" copper tubing for R410A.
L is 0.042" thick or 1.0668-mm, below recommendation.
K is 0.049" or 1.2446, thicker than minimum recommended.

Certainly if someone used M copper tubing on an R-22 system you wouldn't want R410A pressures in it! Could happen. ->

For further information contact your local Actrol Parts Branch.
Andrew Leach. B.Sc, Post Grad. Dip. Chem. Eng.
National Sales and Marketing Manager
Actrol Parts

One place, think Mitsubishi, said they were using smaller diameter E-Coils; [which could then have a thinner wall thickness 'Me']. That may not be the case here though.
Mitsubishi Electric Europe
Air Conditioning Systems Division
Travellers Lane, Hatfield, Hertfordshire, AL10 8XB

We need a USA Standard for all to follow. - Darrell

[bamaheat]

Darrell,
"We need a USA Standard for all to follow." - Darrell
I agree with you.. there needs to be a USA standard so there will be no questions or decisions...its stated in the standard what is to be done.

Thanks for everyones input.

[dash]

We have been installing Puron/R410a replacements since the late
1990's,we never replace the copper if it's the correct size,just nitro.

No issues,thousands installed.

[udarrell]

I agree Dash, at this point, there does not seem to be a problem.

I couldn't find a USA tubing wall thickness standard or code for R410A systems.

Here is the wall thickness conflict.
Type ARC, was probably most used; for 3/4" OD> 0.042" & for 7/8" OD is 0.045" wall thickness; both below the 0.048" listed.

They recommended 1.22-mm or 0.048" for 3/4" OD copper tubing for R410A.
L is 0.042" thick or 1.0668-mm, below recommendation.
K is 0.049" or 1.2446 mm, a hair thicker than minimum recommended 0.048" OD wall thickness.

For example what one mainstream HVAC supply outlet was selling primarily for Refrig & A/C applications in 2003, was 3/4" OD wall thickness of 0.035", way below the 0.048" recommendation by a foreign country.

The recommended thickness was stated as 0.048".
If there is any safety issue here it needs to be code.

Additionally, many have probably used type M which is only 0.032" for 7/8"OD. We know that many would go for the cheaper tubing & may have even been pushed by some at supply outlets.

I believe the existing tubing wall thickness needs to be identified & a wall thickness per OD needs to be Code listed, so everyone adheres to code listed safety standards.

There may never be a problem, however, codes are put in place for safety reasons & the tubing ought not be off the table.

When replacing tubing I would always use Type K, or tubing recommended for R410A. The cost will probably be higher; peace of mind is worth it.

[beenthere]

The strange thing is. They don't make the coils that thick.

[udarrell]

The strange thing is. They don't make the coils that thick.
I believe you are referring to evaporator coils.
You could be correct as they may not be making type K anymore?

This is only referring to the copper line refrigerant tubing for R410A wall thickness.

Type K HVAC copper tubing is a hair thicker than what is recommended by some companies in other countries.

Some supply outlets may not be even be handling type K, they changed to handling ACR gauge tubing.

Type Labeled ACR is 0.042" thickness for 3/4"OD & 0.045" for 7/8"OD both below what another country recommended for 3/4" OD.

All I'm wanting to know from our industry here in the USA is, what copper HVAC refrigerant line tubing is the accepted safe standard for R410A applications.?

[jerryd_2008]

We have been installing Puron/R410a replacements since the late
1990's,we never replace the copper if it's the correct size,just nitro.

No issues,thousands installed.

So if one has an old R-22 AC unit, is the consensus that it is OK to reuse the old lines? Mine is in conduit in the garage floor and then into the duct soffit - accessible but not easy. Also don't want ugly lines running down my finished garage walls.

Does one need to write a disclaimer into the proposal that the contractor decided to reuse the line set in order to protect the customer?

[beenthere]

I believe you are referring to evaporator coils.
You could be correct as they may not be making type K anymore?

This is only referring to the copper line refrigerant tubing for R410A wall thickness.

Type K HVAC copper tubing is a hair thicker than what is recommended by some companies in other countries.

Some supply outlets may not be even be handling type K, they changed to handling ACR gauge tubing.

Type Labeled ACR is 0.042" thickness for 3/4"OD & 0.045" for 7/8"OD both below what another country recommended for 3/4" OD.

All I'm wanting to know from our industry here in the USA is, what copper HVAC refrigerant line tubing is the accepted safe standard for R410A applications.?
Even the condenser coils are not as thick as the copper line set.

[beenthere]

Does one need to write a disclaimer into the proposal that the contractor decided to reuse the line set in order to protect the customer?


No. If he flushes it. There is not problem.

You would have a hard time proving that any problem was caused by re using the line set.

[udarrell]

Right beenthere,

Maybe its copper tubing mfg'ers putting out that info about copper tubing wall thickness. The thinner condenser & evaporator coils are, usually the better the transfer of heat.

I would think the ACR Type would be okay; seems we would have been better warned if it wasn't. They better not come out with something else, -NOW!
- Darrell