Variable Speed (Carrier) vs 2 Speed (Lennox) Furnace

Al D'Ambola

David,
The response to your post has been handled well by the contractors here. However I would find a contractor who is certified to measure the airside of your new system. Variable speed is a great product but if you do not measure static pressure, delivered cfm & system delta-t the only thing you are doing is hoping the fan is working the way it should. After measuring hundreds of systems I can tell one thing most residential fans can't over come high static presure, I know what the manufactures say, but once you start to measure then and only then will you know if the system is delivering the BTU'S.Which is whatyou should strive for.

David Gaudio

Carrier vs Lennox Furnace

I am a homeowner who knows nothing about furnaces. One company tells me to buy a Carrier Variable Speed 58MVP, the other company tells me Variable is bad, that I should buy a 2 speed Lennox G32V. Can anybody help me with some independent knowledge?

Jack_18

Carrier vs. Lennox

Not a lot to pick and choose. The variable speed is the same in both of the makes, by G.E. Biggest thing against variable is cost of a replacement motor at this time. Two stage firing is great, Carrier ckt. board a little better logic with single stage stat, Lennox a little better with the surelight system ignition. My advice, deal with the best contractor.

JOHN HERITAGE

VAR, SPEED

Personal preference look at Trane variable speed. But as already said the quality of the contractor is the most important part of any installation. Even the best car runs terrible if in the hands of an unqualified person.

Steve Ebels

Neither

American Standard AUY series furnaces have the board with intelligent ignition control and the silicone nitride ignitor that you and anyone else buying a (gulp!) f ff f ff furnace should be looking for. These two features will eliminate a LOT of service calls over the (short compared to a boiler) life of any gas furnace now being manufactured. The Am. Std. furnace is two stage, variable speed and offers a level comfort and economy of operation as good as any brand out there.

That being said find a contractor or company that you trust and looks like they will be around for a while. There are a lot of folks in this business who don't have a business, just a 24/7 job and soon grow tired of it. They quit or are forced out of "business" because they don't know enough about business to be in business. Ask for references and ask for a copy of their balance sheet. That last item will make the wanna-bees eyes pop open real wide.

Did that make any sense?

John Starcher_4

Motor.....

....is a two piece unit in the American Standard.

The drive section and the motor section. Last I checked, they rarely fail, and really not that pricey to replace. You can replace only the failed portion, not the whole thing.

Starch

John Starcher_4

Oh, and by the way....

....VARIABLE SPEED ROCKS!!!!!!!!!!!!!!!!!!!!!!!!!!!!

If I were putting scorched air in my own home, I would put in variable speed. We install a bunch of them every year, and all my clients absolutely love them. Next best thing to radiant heat, I always say. I'm not familiar with the Carrier version, but the Trane and AmStd models have dip switches to set the actual CFM desired, and the motor will turn at whatever speed necessary to deliver it.

Set your thermostat fan switch to "ON", and the motor ramps down to half-speed when the thermostat is satisfied, providing continuous airflow. This reduces, if not completely eliminating, stratification and temperature differences throughout the home. The old scenario of the upstairs being warmer than the downstairs can be greatly reduced. Also, with constant airflow, you have constant air filtration. Only downside is you REALLY have to check your air filters regularly.

Definately the most comfortable forced air system out there, and very energy efficient. The blower motor, when running in "continuous fan" mode, draws less than 1/10th of an amp. Very impressive machine.

Starch

Glenn Harrison

Difference between 58MVP and G32V

is the Carrier 58MVP has a variable speed Inducer (Combustion) blower and the Lennox G32V has a 2 speed Inducer (Combustion) blower. Both furnaces have variable speed blower motors that can be set to provide the CFM of air needed to heat and cool the house properly. Once set the motor decides how fast to run to achive the CFM that was programmed. Both furnaces have 2 stages of heating, or a low capacity ad high capacity. The Carrier Inducer motor is a little more tolorent to wind changes and will cost a little less moey electricaly to run due to the variable speed Inducer motor. The Lennox unit also has the Intelligent ignition system which will extend the live of the ignitor that lites the burner, the same as the American Standard mentioned above. The Lennox has a standard 5 Year parts warratny, the Carrier has a limited parts warranty, the length of which I'm not sure of.

Things you want to keep in mind are: 1, Variable speed is the way to go for a forced air system, the best comfort you can get. 2, keep in mind variable speed parts are more expensive then standard furnace components. Better things cost more. 3, Make sure you get the best warranty possible (reference #2) and a service aggrement to keep future repair costs to a minimum. 4, Get plenty of references from the contractors you are working with. Make sure they have installed and SERVICED plenty of the units they are putting in. I say this because I have a customer that had a new house built and the HVAC contractor put in a Carrier 58MVP and a Carrrier 2 stage A/C, and I have been cleaning up their install snafu's for a year, just because they weren't trained in these systems properly. Your new system ultimatly will be only as good as the contractor who puts it in.

Personally, I would stay away from the Lennox contractor who told you "Variable is bad", but at the same time is selling you a unit with a Variable speed blower. However, you can still look at the Lennox G32V with another contractor, just check them out carefully. I would also say that the Trane and American Standard units posted here are also fine units. You should consider getting a quote from a Trane or American standard (A/S) dealer if you have one in your area.

Finally, all the units are good quality units so you will be happy with whichever unit you choose. Just make sure the contractor you go with is the one who will do the best job and be there to take care of you down the road. Your new furnace will be worthless if it can't be taken care of in the future, or isn't installed properly in the first place.

Oh, one last thing. If you have some hydronic (boiler) contractors in your area, another route you could go is a high efficency boiler, a variable speed air handler with a hot water coil connected to the boiler, and an indirect water heater connected to the boiler. This will give you a even more comfortable system due to being able to control the water temp to the air handler based on the outdoor temp, provide higher hot water capacity with the indirect tank, a system that is easier to maintain and will last much longer than a forced air furnace and a standard gas water heater. Just some extra food for thought.

Glenn Harrison, Residential Service Techician

Althoff Industries, Crystal Lake, Illinois

Althoff Industies Link

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John Mills_3

M O D U L A T O R

Forget the old technology! If you want scorched air, at least modulate it! The Rheem/Ruud 94% furnace with modulating input is as close as you can get to hydronic-type comfort in forced air. The gas input varies from 40% to 100% of rated input based on signal from a special thermostat. It's technology that leaves 2 stage way behind. The variable speed blower varies to maintain a hot 65 degree temp rise so you don't get the drafts that happen with some newer furnaces. It's a bit higher in price than the rest due to the special thermostat. I've sold 2 stage and 2 stage variable speed furnaces for years to happy customers. But wasn't til the Mod came out that I've heard customers RAVE about a furnace before.

But if you want 2 stage variable speed, about everyone has it. I've never found Carrier furnaces to be overly reliable. Don't see much Lennox around here anymore. We've sold many of the A-S/Trane. The new variable speed inducer hasn't been to reliable this fall but the rest of the system has been.

If it hasn't been pointed out before, the G32V is variable speed blower!

www.rheemac.com and go to gas furnaces to check out the Mod.

MURPH'

had a guy ask....

me if I was "bonded" once, as I was laughing hystericaly on my way out the door I told him all I had to do was cut a small hole in his ceiling ,not move his house down the road, what a hoot the way people think !!



Murph'

Al D'Ambola

David,

The response to your post has been handled well by the contractors here. However I would find a contractor who is certified to measure the airside of your new system. Variable speed is a great product but if you do not measure static pressure, delivered cfm & system delta-t the only thing you are doing is hoping the fan is working the way it should. After measuring hundreds of systems I can tellyou one thing most residential fans can't over come high static pressure, I know what the manufactures say, but once you start to measure then and only then will you know if the system is delivering the BTU'S.Which is what you should strive for.It's all about delivered measured performance.

rob

Boy, how refreshing

to hear a professional address the core of the issue. Do the math and run the Man J and D. Insist your retailer fursnish you with this documentation. P/L, balance sheet is alot of hooey. If the retailer of your choice can not provide Man J/D, move on and find one who will. You will have made the right choice. The only way is the right way.