Confused about equipment differences, need some feedback.
The wife and I decided to replace our Comfortmaker furnace AC system from 1987, and have two different bids - 1 for carrier (TP5) and 1 for Lennox (EL296V)
Honestly, we just wanted to replace the system with the cheapest/least efficient (80) unit so that when we go to sell the house in (5+ years??? maybe more) we wouldn't get dinged by people saying the equipment was too old. But after looking around, we're not sure if that's the best idea.
Both the bids are for 96 efficiency units, but the differences come with the blower motors. One is an ECM and the other is a variable speed. It's my understanding that the Carrier ECM has several "stages" but isn't a true variable speed.
All other things being equal, are we wrong to go with the cheaper Carrier? The Lennox guy told us that you wont see much of a benefit to going with a high efficiency unit without a variable speed motor because they don't reach peak efficiency until about 6-8 min into their cycle, and ours currently runs for about 4 min, and a unit without a variable speed would do the same thing.
We live in a split level (1600-1700 sqft.), and the basement is always several degrees colder, and we were under the impression that a variable speed that runs more often would help even that difference out, but the Carrier guy told us that the one he has in the bid (TP5) would do that just fine, and that we'd be wasting our money going with the other model because it would require an infinity control unit. We have a Nest we haven't installed yet, so I'm not sure why I would have to buy his more expensive unit.....
We're just not sure which model is going to do what we want it to do... the cost difference between the two bids is around $$$, and at $$$ already, that extra expense for the Lennox unit isn't looking good.
So is the variable speed worth it when we're not even sure we're going to be in the house for much longer than 5-7 years?
Any thoughts or input would be greatly appreciated.
Last edited by jpsmith1cm; 01-20-2013 at 04:28 PM.
This is the Ask Our Pro's forum. In order to post a response here, you must have verified qualifications and have been approved by the AOP Committee. You may ask a question by starting a new thread.
You can find the rules for posting and qualifications here.
Additional infractions may result in loss of posting privileges.
Last edited by jpsmith1cm; 01-20-2013 at 04:28 PM.
Reason: non AOP member
The pricing differences were important to the decision, and based on what I read, I didn't break any rules. I didn't post prices specific to any equipment. The numbers listed were differences in bids and the overall cost.
If I'm incorrect in my assumption that I didn't break any rules, I'd like to be pointed to the specific rule, but this is all I could find on pricing.
"There will be no pricing allowed in the public access areas of this site. Please do not ask for or give pricing comparative information."
The numbers I posted weren't specific prices for anything. Just an overall cost and the difference between the bids.
3. No pricing questions please
Only people who actually see your job can price it accordingly. There will be no pricing allowed in the public access areas of this site. Please do not ask for or give pricing comparative information.
Posts of this type will be deleted.
A price difference is "price comparative information".
If the prices are "important" to the question. Then it is a "pricing question" which is not allowed.
Still not sure how asking if a $$ difference is asking for price information. I just wanted to know if moving from one furnace to a different one was worth the cost. The $$ is not a price of anything, but the difference between two prices that I didn't mention. You might think about rephrasing the rules if what you're trying to explain to me is different than I interpreted it to be.
I'm not seeking price comparative information. I'm not asking pricing questions. I don't think you understand my question or the rules as they're currently written.
Last edited by beenthere; 01-20-2013 at 06:23 PM.
Reason: Price info
I understand your question. If you put prices in this thread again, it will be closed.
They are NOT PRICES... You clearly don't understand your own rules or my point of view... The difference between two prices is not a price. Saying thing A is X and thing B is Y, X and Y are prices. the difference between X and Y (let's say Z) is not a price of anything. Nothing is for sale at Z.
Can anyone else provide any insight about my original question and just assume the cost between the two is enough to wonder if you're doing the right thing....
Both are ECMs, they just go about their biz differently. The Carrier type has speed taps that the installer can set to try to get the airflow he wants. The airflow actually varies quite a bit with different duct static pressures or conditions. Say he wants 1200 CFM for 3 ton A/C cooling. The right way is to measure duct static and look on a graph or chart that tells what speed tap will get him close to the desired airflow. But his readings are with clean filter and if installed now, dry coil. As the filter plugs and coil gets wet in the summer, airflow drops. The variable speed motor is set to desired CFM by jumpers or switches on the board. Unless the duct resistance is very high, the blower motor will be delivering pretty close to what he asks for over changing conditions. As the filter plugs, the motor senses the restriction and tries harder. Also variable speed motors often offer features than the fixed speed doesn't (varies by brand) like slow ramp up for dehumidifcation in the summer or dehumidfy on demand with a special stat. Not sure how many of the fixed speed motors offer 1/2 speed constant fan but far as I know, all the variable speed products do.
I sure like the technology and won't have anything but a variable speed.
It's the dealer, not the brand that makes the difference. Since you wanted a "furnace that will get you by" why have you allowed yourself to accept 96
% unit quotes? There are 92% units out there that have very few "bells and whistles" if you want to go higher than simple 80% units for quite a lot less investment than the 95-96% units. I'd call another reputable company and get quotes on the type of unit you want, not what the "salesman" tells you he'll sell you.
if you unit only runs 4 minuets do not replace it with the same size unit you need a much smaller unit .have them perform a manual j load calculation and if the come back and say its the right size they probably winged it. a basic 13 seer 80% furnace properly sized will save electric in the summer might not save much in the winter .
I agree with catmamacman. I would not change the unit and go back with the same size furnace. You would be simply putting in the same size furnace you already have but just a little more efficient then your current late 80's model. No real savings there. Although a new furnace will
Originally Posted by catmanacman
Have warranty compaired to your old one that does not. A manual j load cal. Needs to be performed to determine proper sizing for new furnace and a/c condenser.
Just remember one thing as you make your decision. Which is that sometimes 5 years turns into 10 years when you think about saling your home and moving on. I have seen a lot of customers tell me the same thing, they just want cheap as they only plan to be there for 5 more years. That seems to be the magic number. You will get what you pay for going with the cheapest system.
I would if you are 100% sure you will be moving in 5 years find a good contractor who will install a 80% gas furance with 13 seer condenser Properly sized. If not 100% sure might want to invest say a mid range system 90-96% furnace and 14-16 seer condenser. Either way you would have a new hvac system with warranty. It just depends all on how long you actually live in the home to offset the cost Differance.
In other words how much is your comfort worth to you for the next 5 years possiable more? With proper sized mid range systems you will have more control over heating functions and depending on the outdoor condensers more control over it. In your case ROI is not lickly with either model if you only stay in the home for 5 more years. At least you will have peace of mind that the system is proper sized, installed and has warranty.
As far a variable speed goes yes it cost more but does help with hot and cold spots in the home, quiter operation, less energy usage and removes more humdity. While variable speed furnaces are a good investment keep in mind that they are not a fix for improper air flow to rooms, undersized ductwork and for keeping areas in your home warmer or cooler. If the duct system is not sized properly or supply/returns going to the areas that you are having problems with are not sized properly. The variable speed will simply allow for longer run times but want Nessary help this areas.
I just timed everything. You need to know that it's currently -12 here though. The furnace runs for about 6.5 min and then waits about 9 min before kicking back on.
Neither company has mentioned a Manual J load calc.
Your old unit is grossly oversized, make sure someone runs a manual J BEFORE you purchase another unit. This is WAY TOO SHORT a running cycle and will GREATLY DECREASE THE LIFE OF THE NEW UNIT. It does sound like you've got a pretty well sealed and insulated home to maintain that long an "off" time however using an oversized furnace will greatly decrease the actual efficiency of the furnace. You can measure your home and do your own manual J using formulas available on internet!!