HVAC replacements that include Air Conditioning are a bit tricky right now.

R410a has been phased out / Equipment: what is left is scraps-- so in all reality what they are quoting you with Carrier is most likely R454b refrigerant. (A2L mildly flammable)

R454b has complications that many are not talking about. (PFAS substances, refrigerant glide, cost, not to mention at times availability problems) Manufacturers consider refrigerant a consumable so there is no warranty coverage for that component if a part fails and starts leaking refrigerant.

Another competing refrigerant is R32 (Also A2L mildly flammable) - One manufacturer as far as I know using it: Daikin (produces Daikin, Amana & Goodman brands) Cons (When the next phase out comes, probably in another 10 years it will be banned just like R454b -- right now it's in line with R410a pricing, No PFAS, No Refrigerant Glide, Single component refrigerant.)

If Daikin equipment springs a refrigerant leak? Yeah it too will cost money for refrigerant. But R32 is likely always to be much more cost effective than anything else. Why? R32 is the common link between all 3 of them.

R410a: R32 50% / R125 50% blend.

R454b: R32 69% / R1234yf 31% blend.

R32: ~ R32 single component.

So these other manufacturers are now trying to hide what type of refrigerant? I didn't see anywhere on that bid what type of refrigerant? (note if they don't hide it they will call it Puron Advance -- this is a direct "brand name" of R454b) Europe has already banned R454b, so take that as another hint for it's longevity. ~ Probably will go down as the shortest used refrigerant of all time or the biggest con job the HVAC manufacturers have ever pulled take your pick.

What I put above is the condensed version. I've been telling folks since 2021 what is coming... it is now at the door. (Choose carefully)

More information video below: currently about 5 parts, each part about 30 to 40 minutes long. (it's not click bait. I know what you tube has become.)

TXC043C4HPC0 is not a Trane furnace model number. I think it might be the model number of the coil, but even then the "43" might be a "48". If you can find the correct the furnace and outside condenser model numbers then the current sized could be determined. It is likely you have an 80K BTU furnace with a 80% AFUE (efficiency) rating. That means the furnace output is 64K BTU (80K * 80%). That is the number you need to compare with the new furnace. Therefore a 60K BTU furnace with a 97% AFUE (58K BTU) may be sufficient. The right way to do this is for the HVAC contractor to do a heating and cooling load calculation and give you a copy of the results.

Each person that came out gave me different sized AC units (2.5, 3, and 4).

Be aware that 2-stage condensers are only available in even sizes. So some contractors will look at your current 3.5 ton condenser and a 3 ton 2-stage AC will work well. Others will want to round up to 4 tons. You can't install a bigger AC if the duct work cannot handle the air flow. The duct work will be nosier and you will probably not feel an additional cooling. Did the 3.5 ton AC keep the house at 75 F degrees on a typical hot summer day? If so then that is an indication it is the correct size assuming there are not duct work problems.

As far as I know Carrier equipment only uses R454b refrigerant. You can confirm this with the installer and the Carrier website.

I’m wondering if it’s worth it to replace everything or just have the control board fixed?

If you were moving within a year I would lean toward replacing the control board. The AC has reached end of life at 25 years if it has never been replaced.

I have not shopped for HVAC equipment recently, but the prices you were quoted seem high for a Carrier Comfort AC and Performance furnace. I do like the contractor is including 3 years of labor warranty. Perhaps you could ask if it can be increased to 5 years at no cost. I recommend getting a 4 inch media filter. The line set should be changed in my opinion. Also ask which Carrier thermostat is included in this quote. You don't need a maintenance contract unless. Ask how much would be saved it that line item is removed.

Austin Air Companie: The refrigerant is listed as Puron Advance. Thank you for the information.

Mike_home: my current furnace is a 2 stage 80,000btu. The quote says this includes the “Carrier Smart Thernostat”… is this what I want? I truly appreciate your insight and response. Thank you!

I did a search and found the model number of this thermostat is TSTATCCEWF-01. Bellow is a link to the page on Carrier's website.

Carrier Smart Thermostat

I don't know much about this thermostat. It seems to support a wireless connection but it is not Carrier's best thermostat. There are better thermostats available and it does not have to be a Carrier thermostat for the equipment you are considering.

80,000 BTU is the input. We don't know the output and if it matches the sizes you are considering.

I live alone in Florida and just had my 26 year old TRANE unit replaced. A few years back I had the motor replaced which cost me somewhere $1,200+ and it continued to worked. My motor did not fail this time, but I developed a leak in the coil and the compressor died. There is no replacing parts this time. I needed a new unit.

I cannot speak to you in HVAC terms, but just as a homeowner. My HVAC guy, who I trust, (I still went out and got 4 bids) told me the days of having a HVAC unit last 20+ years are now gone. The industry has changed. All the major companies make Good, Better, Best units. I went with an ALLIED unit a division of LENNOX. My home is about 1,600 sq ft. I received bids as high as $8,500. I am planning to sell so life of the unit was not a huge issue. This happened in June & the unit works great.

Up until the last 2 weeks the AC has been on to keep up with the heat. Our utility charges are reasonable down here in SWFL and my bill has averages about $109 for the month.

Good Luck to you.

Well, Bev, it looks like you have a heat pump. which is basically an air conditioner with a hundred dollars extra parts. The OP is asking whether to replace and AC and a furnace.

Honestly, OP, I'd just get it fixed - it could go out next year or it could last another 5 years!

I went with an ALLIED unit a division of LENNOX. Yeah Allied is a division of Lennox, they make a number of off brand units.

Ok Beverly,

So I went to their website and this is where things explain better how the deal of the century happened. Because any time you get a record deal, the finer details tend to not add up.

This is the case here, I don't see ANY condenser model of Allied with a 10 year part warranty. NONE. Provide us a Model Number.

1st: Warranty Terms. --- Everything I can find on Allied Units is 1 year parts / 5 years compressor / 3 years on the condenser coil AND the condenser coil is aluminum. If you are in or near salt water spray? I already know what will happen with this one.

(you don't plan to stay living here, so maybe you escape it.)

click to enlarge:

2nd: Refrigerant. These units are R410a, and R410a is A1 flammable rating so it doesn't need additional cost Mitigation Controls.

3rd: It's an Air Handler with Electric Heat -- doesn't appear to be a heat pump according to the documenation you provided.

So to sum this up... It's only a good deal for Beverly IF, the unit suffers no problems.

She's in Florida a more warm climate than cold like Ohio, with additional corrosive threats like salt spray from the ocean or the Gulf of America.

I'm not seeing any "New Refrigerant" equipment from Allied from their website. It appears they mostly make commercial equipment / not residential. Click here to go to the website.

Because R410a equipment becomes illegal to install very soon, this dealer probably got a deal on it. Typically these deals rarely favor the customer, unless you're selling the home quick (less than 3 years usually)

I service the Katy, Texas area.

Hi, Lexi,

A 25-year old HVAC system is past its useful life expectancy. Replacing the system before the end of 2025 with a new, more efficient system may qualify for federal tax credits of up to 30% of the installed cost (but not more than $1,200.) These expire at the end of 2025. You may also qualify for state-specific tax incentives/rebates. Plus, you'll get the benefits of a more efficient system which should be reflected in lower utility bills. Your local HVAC contractor should be able to help you understand which of the proposed system(s) qualify. For what it's worth, I'd go for the 97% AFUE furnace option if I lived in your climate zone.

Just a small point - I'm encouraged by the information that you're shared, that the HVAC contractor is downsizing the furnace compared to what you have now. Perhaps the AC too.

I take that as a sign that legit heating and cooling load calculations were done, a step competent and conscientious contractors consider essential and not optional.

I believe Austin has said in the past that he usually doesn't do them when replacing existing equipment.

I believe Austin has said in the past that he usually doesn't do them when replacing existing equipment.

What I've said is no where near what Mr. Fudd believes.

Sizing is important, however sizing is never going to be a perfect "metric".

Why? If you nail it and find a perfect size... how correct is it?

90% of the time it is over sized, even worse if your calc spits out a number in which the manufactures don't make.

If the heat load says: 52,000 BTU's not quite 4.5 tons. Equipment makers don't make 4.5 ton equipment. If you go to 2 speed, the equipment makers don't make 1/2 ton sizes.

Round up / Round down. The magic flame ball in the sky, where you live heat of the day -- the part of the day your system sizing more or less comes from?

No, no, no. Let's argue over this 3 hours a day divided by 24 = 1/8 of a day we are going to argue over. Granted some areas are probably more "over sized" than other areas, you know areas like where Mr. Fudd lives where he can afford to wait for 6 weeks for someone to come and change out his equipment because he believes waiting long periods in discomfort is the tried an true formula for getting quality work.

------ If I am replacing an AC?

The size is tied to the existing furnace as well as the duct system. In many cases that furnace and duct work has sit there for 15, maybe 20 years. The duct system is largely been sized for that furnace as well as the AC. Furnaces here can last 30 years if not longer.

To change the size is good fodder for those who enjoy spending OPM (other people's money)

If sizing is believed to be "off" -- pulled this magic more than once. We call this form of Magic?

Inverter --- 1% up / 1% down in steps.

So Inverters are built how? 5 ton don't make 4 tons or 4.5 tons -- if you need 4 tons a configuration set up is used at installation to make that 5 ton run like a 4 ton.

3 ton don't make 2 tons or 3.5 ton -- yeah so apply here the same above.

--------------

If it comes down to mis-matched or other problems? more money. I can get crazy numbers too just like any other HVAC company. Most of the time -- people are a bit more rational than Mr. Fudd and his rhetoric.

Heat of the day here is 3pm to 6pm (most of the time) under heavy heat waves 3pm to 7pm -- you know flaming ball in the sky beating down on you heat.

24 hours in a day divided by 3 = 1/8 of a day. 100 divided by 8 = 12.5 100-12.5 = 87.5% of the time your poor AC here is over sized. (This is if you're perfect, which given what is made in the size you need vs what is available? no one is this perfect.)

Well we measure perfection by how much you're gonna spend to rip everything out. Because to even get close to perfection, that isn't that close -- is what you will have to do.

Many of the homes I go to have more than one system? uh yeah. See Mr. Fudd can not imagine anything like this conundrum.

So to get to this so called perfection metric that is no where near perfection? 87.5% of the time over sized. This is the so called perfection metric.

Well sorry sir you have 3 systems here so to make sure that our cool calcs are right you need to rip out all three systems and redo them all. Shouldn't be more than $50,000 all new ducts, gold plated thermostats -- fancy dancy air scrubbers, and then we'll maintain all these new systems for a paltry $1,000 a year.

Nope, sorry Mr. Fudd your reality is largely based on Fudd.

Tell me what your budget is -- I can easily exceed it. If your budget is too low? Maybe I can repair it? I just repaired a 24 year old R22 freon unit yesterday afternoon. 2 units at that house, both R22 Freon.

I'm gonna go out on a limb here and say those units are properly sized? uh yeah.

Well a heat load calculation is magical. To some, sure. I've done them, not via some calc in the sky but long hand. So I am all to familar with slight of hand too. There is nothing magical about them. A tool in the tool box for those that fully understand the strength of them, not to mention the fault thereof.

I just started yesterday? No over 30 years in HVAC.

If you don't like what I say now, you certainly won't like what I say if our paths cross. Reality is better than fiction. (OR if you prefer Truth over elaborate well crafted lies)

The heat load calc fault thereof:

Insulating R values of the home, the walls, the attic, the windows, the doors.

If you don't know these R values? yeah you won't... so guess. This is heat load accuracy magic.

The home is how old? How well homes are sealed and insulated change with the times. A 20 year old home is no where near the tightness or insulated value of a 5 year old home. No 2 homes are alike in this regard. Because? these values / requirements change all the time.

Insulation values in the walls change? yes. Sorry sir I am going to need to cut into your homes walls to see the R value of the insulation in there? No, No, NO! Let's guess. - This is accuracy of a heat load defined.

But what if there is no insulation in the walls of the home or the Attic? I'm walking away from it until you insulate it. I have this little thing, I rarely talk about called "company policies". Remember I've been doing this for over 30 years. I know when to walk away, I also know when to run.

Oh, so you mean it's your way or the highway? Good we're starting to understand one another. If I am going to do it, it (whatever it is*) is going to work. *restrictions / limitations apply

Windows, how many different kinds of windows? R values, thermal values -- again more guessing. The home owner may not know such things... probably not 9 times out of 10.

Don't worry Heat Load calcs are magic. -- this is the pro way to suggest our way is better because we are shooting to be right 12.5% of the time.

--- areas of Mr. Fudd? you could probably put in a window unit and call it a day. Can't do that in Texas, well you can but the HOA may fine you for it.

Ray,

You may have been in the business for 30 years, but lots of threads posted on houzz.com are clear evidence that you know little about HVAC equipment sizing. So you dismiss sizing systems by the calculation processes established by the Air Conditioning Contractors of America (ACCA)-- your own industry trade association.

There's a difference between properly-sized systems and where the (properly-sized) system is operating within its design range. Systems are typically sized to deliver comfortable conditions 97.5% of the heating or cooling hours in a season. The outdoor design temperatures are published in the code for the locality. A (properly-sized) air conditioning system operating when outdoor conditions are near maximum design temperature will be operating near its maximum design capacity. If the outdoor temperature is less than design temperature, the same system is operating at the lower end of its design capacity--it's not oversized. You might recall being educated on this subject in the following thread which houzzers can visit for clarification on the subject:

https://www.houzz.com/discussions/6480904/how-do-i-know-if-my-house-hvac-is-sized-correctly

You can also get information in ACCA Standard 5 (Quality Installation Specification.) Houzzers can download a copy free of charge and compare their HVAC contractor's proposal versus the ACCA's standard.

Charles you are a builder that is supposed to?

Size the equipment appropriately from the get - go.

If you did your job? no, no, no. I am a builder after a year I'm gone, baby gone.

Retro-fit market is not like the build new market, not by any stretch of the imagination.

At the end of the day... it's still a guess -- unless you know the R-values you know because you're a builder that is um -- BUILDING NEW.

I've seen others use slight of hand Heat Load Calc Magic to suggest the builder was wrong so a competing company could come and rip out a whole HVAC system that was 5.5 years old.

I repaired the unit, because the home owner didn't believe the rhetoric.

SO take your pick at your own peril.

Whether it's for a bridge, a plane or an HVAC system, design calculations are rarely exact. They are approximations. That doesn't dismiss the need for them. Fortunately, unlike a bridge or a plane, there aren't life safety implications of getting an HVAC calculation wrong for a residential installation.

Checking the sizing of a system for an existing home is marginally more difficult than a new home. Let's look at how you might go about determining the inputs for the manual J calculations:

Wall areas, floor areas, ceiling areas, and glazing areas in an existing home can be accurately measured. The home's attic and under-floor insulation can typically be inspected so their R-value wouldn't have to be a guess. A wall insulation R-value can be reasonably inferred by knowing the wall thickness, the year the home was constructed and researching the code-required R-value for walls in the local at that time. You may also be able to get a peek by removing a wall switch plate or receptacle plate and having a look in the wall cavity. While there's a big difference between no wall insulation, and say, R-11, the difference between R-ll and R-15 isn't all that significant in the calculation. The U-values for window assemblies will often be an educated guess, but the U-value for double-pane or triple-pane glass can be reasonably estimated. You can also consult the glass manufacturer using the information etched in the lower or upper corner of the glass to identify it. The biggest unknowns are typically the air exchange rate and duct leakage which can be measured (my HVAC contractor is certified to do both and the municipalities in which we build require both for new construction.) If you're in doubt, you can vary the value of any input to the manual J calculation while holding all the others constant and check the effect on the overall heating or cooling load. And, of course you can check with an ACCA-certified HVAC contractor in your area.

Elmer J Fudd

19 hours ago

I guess a long and rambling comment attempting (not successfully) to discredit one of his industry's best practices was to be expected.

It wasn't to discredit it.

It was to explain it's not what it's been made out to be.

How? This thread we're in right now proves it. DUH.

No two calcs / estimations are going to be the same? SO?

The home owner is left to guess now on top of all the other "guessing".

No, no, no... according to the builder (who didn't get it right when he built the home and knew all the R-values?) because it's just an estimation.

Whether it's for a bridge, a plane or an HVAC system, design calculations are rarely exact. They are approximations. That doesn't dismiss the need for them.

-----------

From the very first post of the thread>>> Each person that came out gave me different sized AC units (2.5, 3, and 4).

---------

Well it's a matter of opinion... we don't really know so let's let the home owner guess which one of us is right. Then let's guess some more in a forum board. Because these are the HVAC industries best standards!

LOL. Enjoy, have fun. I am your host, welcome to Fantasy Island.

The discredit? it's more of a mockery, because you're telling me the builder can't get it right on day one. To that end, builders do make mistakes -- but more often than not it's in the design of the system / or lay out if you will. To spot those kinds of mistakes? Remember the builder is long gone by that time.

So in the meantime we'll continue to argue about the guessomatic sizing will fix everything clause. Yet, no two, even 3 contractors will tell you the same, a few people on a forum board will argue well these are the standards set forth by "groups of people" who tell us these are best practices -- the builders are let off the hook to getting it right the FIRST time, the guesses will continue to flow like molasses in July... then the home owners can guess some more.

Gee, I "guess" that is exactly what we are doing huh? oopsie, I just discredited the whole process yet again.

From the builder "They are approximations" --- or if you prefer -- A guess?

How could you not come to any other conclusion but that? Explain yourself Mr. Fudd.

How dare you discredit the only one thing we can argue with you about!

Ray,

The HVAC equipment sizing process (ACCA manual J and S) you routinely try to discredit is one developed and promoted by your own industry trade association. As Elmer notes, it's a best practice that's also promoted by building scientists. I know you don't pull permits or work in areas that require them, but the municipalities in which we work (both new construction and remodeling) require that manual S, J, and D calculations be submitted at permit application. Only one of the three HVAC contractors bothered to check sizing. The fact that they even attempted to follow the methodology specified in ACCA's quality manual makes them a standout. The customer need not guess which sizing is right; one contractor produced calculations as the basis for their recommendation; the other two produced the guesses.

As I have said countless times on here Charles, I am "mostly" an HVAC repair contractor.

You don't pull permits for AC repairs. How could a builder know that? my bad.

Some times repairs involve replacing "some" equipment. That equipment sizing is already set, a heat load calc could change it to the fact of needing all new everything. You can't really upsize or downsize an Air Conditioner in which the furnace / and duct work are to support the already existing AC size.

Often times if I get a full on HVAC replacement requiring furnace & AC, the home often times has more than one AC. -- so upsizing and downsizing is a moot point as then it would affect the other areas of the home.

A permit isn't going to have another guy come out and check the math of a heat load calc. So one can only believe the one performing the calculation is right? Yet the original size is wrong? Why didn't the permit people catch that?

The OP said her homes AC was a 3.5 ton, but none of the estimates included that size? So this 25 year old 3.5 Ton AC system has been wrong all this time.

Better late than never! (or was an error made in the one company that performed the holy grail heat calculation?)

It's not hard to manipulate even unintentionally up or down for that matter the number the heat load calc spits out. Then from there you either round up or down. That is accuracy!

In another 25 years... maybe we'll find out if they too were wrong? Because industry best practices are to do the calc again.

As I have said countless times on here Charles, I am "mostly" an HVAC repair contractor.

Ray,

If you are doing mostly repairs, and few new installations, then why do you harp on the topic of doing a load calcualtion? We realize your customers in Katy, Texas think a 5 ton AC condenser is the right size. Installation of new HVAC equipment has become very exensive. I feel the HVAC contractor should spend the time to determine if smaller equipment is appropriate.

We can't assume the original builder's HVAC contractor installed the correct size. The load calculation is one of the tools HVAC professionals use for best installation of their customers. Used correctly it has the potential to save the customer money.

"AAC: You can't really upsize or downsize an Air Conditioner in which the furnace / and duct work are to support the already existing AC size."

I tried to convince the two contractors from which I asked for quotes on replacing my system that eighteen years of experience in this house tells me that I don't need 5 tons. They both said "Five tons is what you have, five tons is what you need." The best I could do at a reasonable up-cost is get a two-stage (3.5 tons on low, 5 tons on high, as I understand). The installing contractor didn't change anything about the ductwork. It runs at low stage 99% of the time during the heat of the summers since it was installed in January 2022 (setpoint 78°F the first couple years, 77°F in 2025). It cycles between low and high in heating when the ambient dips below 30°F but the auxiliary doesn't run except during defrost (setpoint 69°F).

How is it that the system works running at low speed (the blower speed reduces accordingly), but a single-stage 3.5 ton or 4 ton system would be unable to function?

" How is it that the system works running at low speed (the blower speed reduces accordingly), but a single-stage 3.5 ton or 4 ton system would be unable to function? "

Either because of the contractor's ignorance (whether real or pretend) or incompetence. Likely a little of both.

I don't know why you would engage a contractor who wouldn't listen to what you wanted. I wouldn't have.

My second place is a poorly insulated 1500 sq ft plus some structure in a development, in a warm and sunny coastal location. The load calc for cooling came out a bit over 2.5 tons. In talking it over with the contractor, I asked what he thought. He said something to the effect of "most contractors would round up to 3 tons, but if this were my home, I'd put in a 2 tonner". So that's what was done. It works great. It provides great comfort and consistent temperatures.

Good thing I'm not in Katy Texas. The conversation would have never happened.

We realize your customers in Katy, Texas think a 5 ton AC condenser is the right size. Installation of new HVAC equipment has become very exensive. I feel the HVAC contractor should spend the time to determine if smaller equipment is appropriate.

I have installed all sizes from 2 ton to 5 ton, there is very little difference in cost from 2 ton to 3 ton. Cost from 4 ton to 5 ton: again very little difference. If I am at a 1500 sq ft house with a 5 Ton AC? you don't think I would be requiring a heat load? You want to argue just to argue, assume things that aren't true.

I have said>>> A heat load calc is a tool, this doesn't mean you should act like one.

Remember this one? It was a 3 ton Mike, not a 5 ton. I have an update to this story just no time to make the video just yet.

R22 to R410a Conversion -- the hard way... because it requires SKILL. Stay tuned to the end of the video I do my "Freon Taken" skit.

I tried to convince the two contractors from which I asked for quotes on replacing my system that eighteen years of experience in this house tells me that I don't need 5 tons.

(I wasn't one of them) Seems to me we had a conversation on this board and I tried to sell you on the idea of the Bosch BOVA 2.0 -- steps in cooling 1% up and down... yet it also seems to me you were hung up on the Trane brand. The Bosch BOVA 2.0 could have given you even better -- put the sizing guessing game to bed. (But Bosch is premium equipment so cost also entered the fray)

I have had customers tell me (more than one) -- we had a company here that said this should be a 5 ton unit unit versus a 4 ton (what they had) -- I told them, Hey we don't have to guess here --- Bosch makes a 5 ton that can be configured to be a 4 ton. So we can start at 4 Ton, if it's not enough then I can come back and configure it to be a 5 ton.

In the examples we ran the test one was configured at 5 ton, the other 4 ton (both as sized before) and neither of them requested a reconfiguration. ( Prove me wrong scenario, I'm willing to admit if I am wrong -- but 30 years? no. You only use what you know. I use what I know -- no comparison if we're all being honest here. -- you know what goes on at your house, I know what goes on at how many more homes than that? For over 30 years.)

1% cooling up and down, in 1% increments. It will always deliver the amount of cooling you need and as an added benefit it will dehumidify better than any air conditioner you have ever had.

----------

The repair market is bigger than most realize, the contractor who installed this (not me) couldn't answer his phone. Oh well he must have been busy, it proves how good he is? That is the funniest, crazyist thing I have ever heard Mr. Fudd utter as a way to determine how good or bad someone is. -- The "nearly" always readily available guy is no good. -- Good one.

About 18 months old... the unit was a 2022 model, but installed in April 2024, I saw the guys paper work. The unit, low on Refrigerant. Not just a "little low" flat. nada, zero, bupkiss, hasta la vista.

(click to enlarge)

So what does this have to do with sizing? It's not working like this.

For some like Mr. Fudd, he could afford to wait for 6 weeks to see who is the busiest contractor and then pick them. ( while some people are going to want instant gratification or as close to instant as possible.)

It's November here and I am still running AC service calls? say what? People like to assume I make stuff up. They'll twist my words and assume every which way from here to the moon.

They are all myths, in their own heads.

I service the Katy, Texas area.

"The load calculation is one of the tools HVAC professionals use for best installation of their customers. Used correctly it has the potential to save the customer money." Indeed. A load calculation has the potential to reduce the initial (or system replacement) cost, the system operating cost, and to improve occupant comfort, too. Although Ray doesn't do load calcs and operates only in municipalities which don't require permits and inspections, the Texas Dept. of Licensing and Professional Regulation requires load calculations because they're required by the International Mechanical Code (M1401.3,) which Texas adopted. The TDLR publishes a helpful flyer on the subject which you can peruse by clicking on the following link:

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.tdlr.texas.gov/media/pdf/Consumer%20Protection%20-%20ACR%202.pdf

The following text is excerpted from the flyer:

"When a contractor is bidding to do work for me, what should they do?

● They should inspect your HVAC system before beginning repairs.

● They should perform a heatload study.

● They should do a duct work study.

● They should specify the makes and models of the equipment, including model numbers, names, quantity, manufacturer warranties, documentation, and energy ratings.

● They should provide bids or estimates in writing.

● They should leave all the owner’s manuals, documentation of installation procedures, AHRI certificate, and any records of measurements and testing."

Ah, Houston we have a problem....

No where have I ever said I don't do heat load calculations. (that is a myth in the builders head that couldn't do the heat load calc right the very first time -- when the house was built.)

What I have said: I don't do them for FREE.

If I am going to do one, there are requirements. Most of the time upwards of 95% of the time I am repairing an Air Conditioner.

Only a PE shrill is going to come to a broken AC and say hey we need to do a load calc to see if this AC unit is the right size or not and then proceed to say you need a more often than not bigger not smaller AC. (PE? = Private Equity, not engineer)

I'm more likely to: repair it, if possible. (you don't need a heat load at that point to do that)

If you want a heat load performed: Tell me in advance I'll come to your house and tell you what the cost will be to do so.

Prices differ from one house to another, if you have multiple units I require the heat load to be for the whole house, not just the area of concern in which one unit is serving.

Permits and inspections do not check or do a heat load calc to prove the one being done is accurate or not. (PSST: This very thread proves it -- and the area in question is NOT Katy, Texas -- it's Ohio)

Try and make it make sense. Good luck. Fun, fun, fun.

---------------

Ray,

If you are doing mostly repairs, and few new installations, then why do you harp on the topic of doing a load calcualtion?

Everyone loves a good argument and there's is plenty to argue about in the realm of heat load calculations. After doing 1000's of them in my early career I could see they aren't always what they are cracked up to be... we'll give you a total (of that) can be easily skewed one way or another... then to be exact "you know best practices" yada, yada, yada --- the total it gives you the equipment doesn't match up so you either then round down or round up.

If you get to 60,000 BTU's most 5 ton AC's don't even hit the 60,000 btu threshold. Most of the time at best "these days" it's around 57,000 BTU's -- some may not even hit 53,000 BTU's. (yet these are considered 5 tons, not 4.5)

The only way you're likely to hit those values is Inverter like the Bosch Bova 2.0 at that upper end, but the Bosch works in such a way, that it will never deliver 60K BTU if that isn't needed via an assorment of proprietary algorithms in which the unit makes ramping decisions.

The importance of a heat load is mostly in the realm of preventing mold growth, as an air conditioner for my area in particular (very humid area more often than not) a larger over sized air conditioner will not run long enough to remove humidity. It will for the lack of better terms, bang on and bang off.

Humidity removal via an air conditioner is not the primary goal. Air conditioners are designed to lower temp, not focus on dehumidification. Even a Bosch Inverter has it's limitations, it does not "control" humidity. Trying to dehumidify with an air conditioner more often than not results in over cooling, to the point you're too cold.

Adding a dehumidifier, you just upped your overall cost and your electric bill will also go up too. Some people are sensitive (especially in a hotter climate like mine) if the dehumidifier is running will spit out 90F air (with the AC cycled off)

In some instances a home's best fit may be to do actually that if "control" of humidity is important. Most of the time the cost, the possible heat sensitivities, maintenance and ultimately the replacement of such systems should be weighed?

Just arguing over sizing alone is a very small metric in the grand scheme of things, But as we have proven with this thread... it's a good argument and people LOVE to argue.

I don't care what we talk about here as long as it's about HVAC --- doesn't matter to me. It's what I do. (If you don't like how I do it? Don't care about that either, nothing you have said or done for over 10 years I've been posting here has done anything to my world in Katy, Texas -- because I have a slew of customers that initially was around the West Side H-town area, but eventually Katy took over. You go where the business is.

So the thought that I only service areas that don't require permits? it's laughable just as much as anything else a builder is going to talk about all the while and intentionally saying he doesn't do the heat load calc correctly either. It was wrong from the day the foundation was laid, isn't that right Charles?

So much fun. I love HVAC. I let you decide what we're going to talk about.

HVAC has never been a 1 size fits all market.

Ray,

There's enough evidence in past threads here on houzz.com that any load calculation you perform and the associated equipment sizing wouldn't be worth the cost of the paper it's printed on. Here's one such example:

https://www.houzz.com/discussions/6480904/how-do-i-know-if-my-house-hvac-is-sized-correctly

Charles, same old dog no new tricks.

Nothing has changed since then... look this thread we are in proves it again you don't need to look backwards.

and this time it's Ohio.

Again, Charles is telling you he didn't get the heat load calc right either since the day the foundation was laid.

The builders are known for being the biggest smoke screen blowers there are in the housing market. Charles should focus on his own work?

Houzz.com forums are open to home owners, builders, remodelers and trade professionals alike. This thread isn't about homebuilders, Ray. It's about HVAC equipment sizing.

My 18-year engineering career involved a lot of HVACR work (design, installation, operation, and maintenance) of commercial and industrial systems for a major food manufacturer. Along the way I earned a P.E. license. Those experiences have served me well as a custom homebuilder and remodeler collaborating with my trade partners to deliver better performing homes. While my clients hold me accountable for their comfort and the performance of their homes, it's my HVAC contractor who is responsible for design of the HVAC systems and who pulls the mechanical permit and is subject to inspection. He's well qualified for task. We appreciate collaborating with each other on design and performance of HVAC systems which is why he's been my exclusive HVAC partner for the past 20 years. You might follow his example. Your clients would certainly benefit.

"AAC: Seems to me we had a conversation on this board and I tried to sell you on the idea of the Bosch BOVA 2.0 -- steps in cooling 1% up and down... yet it also seems to me you were hung up on the Trane brand. The Bosch BOVA 2.0 could have given you even better -- put the sizing guessing game to bed. (But Bosch is premium equipment so cost also entered the fray)"

My question above isn't regards to the virtues of this brand vs. that or variable-speed vs. other. It's why does a two-speed system running on low/3.5 tons work nicely on the same ductwork which was designed for 5 tons and that (your words) won't work for a single-speed 3.5 ton (or 3 ton or 4 ton) system? If the 5-ton ductwork won't work for a smaller-than-5-ton system, then how can it possibly work for a Bosch BOVA 2.0 that's throttled down by 80% of capacity, or whatever?

Also, when I do a search at Bosch HVAC website for a dealer within 200 mi of Katy TX, the result shows one, in Lufkin?

I have installed all sizes from 2 ton to 5 ton, there is very little difference in cost from 2 ton to 3 ton. Cost from 4 ton to 5 ton: again very little difference.

Ray,

I have not shopped for AC condensers recently, but given the big increases in HVAC equipment during the past few year you will have to forgive me if I am a little skeptical with your response.

Can you provide what would be the price difference to install a 3 ton verusus a 4 ton AC condensers in Katy, Texas? Let's narrow it down to a Goodman 2-stage condenser, a brand I believe your distributor supplies and uses your prefered R-32 refrigerant. You can pick the model numbers for this excercise.

The cost difference in the equipment is not a relevant consideration. The heat gain/loss data is what matters, assuming cooperative duct sizing. And since usually the REAL analysis usually determines, not surprisingly, that the existing equipment is too large, duct sizing problems, if any, are remedied.

Ray, do you buy your shoes two sizes too big because they're the same price as the right size? How about pants?

Charles/Ray: I take it you two are long retired or I don't know how you'd have the time to type such long rebuttals to each other?

sktn, I don't know if you caught the following comment from Ray:

" you know areas like where Mr. Fudd lives where he can afford to wait for 6 weeks for someone to come and change out his equipment because he believes waiting long periods in discomfort is the tried an true formula for getting quality work. "

The background to this was some years ago, in a civil exchange, I told him that when I chose the winning proposals (highly recommended contractors, two different jobs, three systems in total in two different locations, the ones chosen were not the cheapest ones), that both contractors were extremely busy and working off install backlog schedules. Both had split teams, those who answered repair and emergency calls, and others to do installs. One wait was 4 weeks, one was 6, which was fine with me and presented no problems at all. He was flummoxed,

I've told him many times that the proposals related to functioning installs that I wanted to proactively replace, that the proposals took place in winter with the waiting periods in the Spring/early Summer, and so neither inconvenience nor discomfort were involved, but that's never registered with him.

I suspect he'd never heard of HVAC contractors so successful and so busy as to have weeks-long backlog schedules. And perhaps that's not his reality. All the good ones in my area do and I suspect the same is true in most places. Some even decline bidding at times because they want to work down their backlogs before taking on more work. Perhaps he starts most weeks with a mostly open schedule and waits for the phone to ring.

Long way around to say to your comment - he seems to have plenty of time.

sktn77a,

Houzzers expect and deserve accurate information from professionals. When they get self aggrandizement in lieu of factual content you can bet I'll take the time to push back whether I'm retired or not (and I'm not.)

Charles Ross Homes: it's my HVAC contractor who is responsible for design of the HVAC systems and who pulls the mechanical permit and is subject to inspection.

According to following the "best practices" the heat load calculation is wrong before the foundation finishes curing. But we won't know this until 25 years later. (according to the very thread we are in.) No, this is "best practice".

It's still the same result if you're going to just follow the mantra. No one is ever right. That is what we are supposed to believe?

Houzzzers expect and deserve accuatate information: Charles according to you own metric it's not accurate... well around these parts we give approximations -- you said it yourself in this very thread. --- that is not accuracy.

If I was wrong to challenge the system? The OP of this very thread would have gotten all identical bids --- but none of them were the same including offering a system in the current tonnage the home has had for 25 years. --- it's been wrong for 25 years! Oh well it's good now that we know it was wrong? --- This is your best practice in action. This thread proves it.

Dadoes: My question above isn't regards to the virtues of this brand vs. that or variable-speed vs. other. It's why does a two-speed system running on low/3.5 tons work nicely on the same ductwork which was designed for 5 tons and that (your words) won't work for a single-speed 3.5 ton (or 3 ton or 4 ton) system? If the 5-ton ductwork won't work for a smaller-than-5-ton system, then how can it possibly work for a Bosch BOVA 2.0 that's throttled down by 80% of capacity, or whatever?

Reduction of humidity or certain people like a different temperature. What is comfortable to you may not be comfortable to someone else. See all of you talk about what is comfortable to you? Yeah what you know as comfort? What is comfort really?

Not to hot, not too cold... just right. So how do you explain vanilla vs chocolate vs strawberry as to which is best to someone who has not had any of those flavors and the entry to those flavors is $1000's of dollars. Let's baffle them with BS. But we already know the flavor of BS, because that is free and on display everywhere.

In terms of there being no contractor for Bosch near where you live? I only talk about things that are in my control, not out of them. There is no perfect option when it comes to HVAC. I don't have to point you far to prove that, you're in neck deep in this thread. LOL.

Different opinions don't bother me as much as they do the 3 or 4 of you. There's far differing opinions in the beyond outside the reaches of Houzz.

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sktn77a

13 hours ago

Charles/Ray: I take it you two are long retired or I don't know how you'd have the time to type such long rebuttals to each other?

I took typing class in high school so it's not what I would call difficult to bang out a long winded reply. I can't speak for Charles... but I'm merely filling in my morning drinking coffee time coming here of a morning before I start my day.

I might spend 30 minutes here most days.... not long. Now if you can't type -- yeah I'd probably be in here up until noon typing out some of these posts. (More myths in the heads of people I touched on a few posts up) .

----------------

Mr Fudd: The background to this was some years ago, in a civil exchange, I told him that when I chose the winning proposals (highly recommended contractors, two different jobs, three systems in total in two different locations, the ones chosen were not the cheapest ones), He was flummoxed,

Yeah I am so flummoxed I keep mentioning it over and over and over again. This is being flummoxed. There's a not so cheap contractor here in H-town that will come to you for free, they get busy too... they have got probably more than 30 install crews. Probably won't have to wait for 6 weeks though. LOL. This is comfort too. What 1 finds comfortable others will not.

Yeah, I'm flummoxed. again more myths. We'll spin everything every which way to say we're accurate all the while by being inaccurate. Comfort. How do you define it?

The cost difference in the equipment is not a relevant consideration. The heat gain/loss data is what matters, assuming cooperative duct sizing. And since usually the REAL analysis usually determines, not surprisingly, that the existing equipment is too large, duct sizing problems, if any, are remedied.

Again there is very little cost difference from say 2 ton to 3 ton or 4 ton to 5 ton even smaller difference in price from 2 ton to 2.5 ton or 3 ton to 3.5 ton. Most of the time it might be a few hundred dollars.

This however does not negate the sizing conundrum as to which is accurate. The measure to being accurate here is again to guess. Well some one took the time to measure so that guess must be more valuable to choose from. Sure, you can go with that theory but in my experience it's used as a metric to often times dupe you.

How? My climate furnaces last a long time here. The easiest way to get a whole system change out would be how? Tell some one they have the wrong size. Congratulations.

No one is going to double check that work. Even if you live in an area in which permits are pulled.

You'll have those that argue and say this is the right way according to best practices and they'd be right... but? You won't know if you're getting hoodwinked all the while following the so called "best practices" mantra.

Now if you disagree with my profound wisdom... you can't just say I'm flummoxed.

I'm fine with that. LOL.

----------------------

Mike home

Ray,

I have not shopped for AC condensers recently, but given the big increases in HVAC equipment during the past few year you will have to forgive me if I am a little skeptical with your response.

Can you provide what would be the price difference to install a 3 ton verusus a 4 ton AC condensers in Katy, Texas? Let's narrow it down to a Goodman 2-stage condenser, a brand I believe your distributor supplies and uses your prefered R-32 refrigerant. You can pick the model numbers for this excercise.

It's my opinion that if you're wanting 2 stage equipment the better value is Inverter, such as the Bosch BOVA 2.0 (although there are new gotchyas if you decide that way now) Now the cost diffences between those options (Inverter and 2 stage) blur and inverter is the far and away better value, in my opinion. (you only get my opinion from me, I'm not even influenced by those on this board. )

So while I do sell Goodman equipment it is not the only choice but with refrigerant changes and such an AC install going forward will be "at least" a Condenser and a Coil & mitigation controls. The mitigation costs are the same no matter which size. ( I mention this because the video shows me only changing a condenser, due to flammability of newer A2L refrigerants this is no longer possible to do a condenser change only.)

The difference is the cost of the equipment --- this difference from 3 ton to 4 ton in single stage configuration R32 is that the 4 ton equipment is $500 more. This doesn't give you the entire costs of the job because those costs can vary some and prices change all the time. But typically a $500 difference is almost always right a jump from 3 ton to 3.5 ton might be $200 or $300.

BUT to decide which the 3 ton or the 4 ton? If your furnace does not support a 4 ton, I am not going to quote a 4 ton. Because it won't work, this is a hot climate here we run our AC's 10 months of the year here.

---- to get into 2 stage you're really in rip it all out and start over because 2 stage systems were largely to be sold as complete systems. The Bosch Inverter doesn't require a full system change out, that perfectly good furnace can be used with the Bosch Inverter. Each climate area is unique with it's own set of challenges. This example shows though how the Bosch Inverter "premium equipment" can give you better value than a merely 2 speed vs upwards of 60+ speeds depending on configuration and sizing of the machine.

-------

It's 6:30 am.

It's my opinion that if you're wanting 2 stage equipment the better value is Inverter, such as the Bosch BOVA 2.0 (although there are new gotchyas if you decide that way now)

Ray,

You have stated in the past your customers have 90%+ gas furnaces. Selling them an inverter type heat pump could be a hard sell. In climates where temperatures are much colder than in the winter than Katy, Texas most homeowners will want to keep their gas furnace. If there are "gotchyas" then this could be an additional reason why a homeowner may not switch to a Bosch BOVA 2.0 for heating.

The difference is the cost of the equipment --- this difference from 3 ton to 4 ton in single stage configuration R32 is that the 4 ton equipment is $500 more. This doesn't give you the entire costs of the job because those costs can vary some and prices change all the time.

I am not a HVAC contractor, so I could be incorrect in what I am about to state. It is my understanding is that HVAC contractor will typically determine the labor cost based the equipment cost. For example a 4 ton condenser which may cost an additional $500 could result in a $1000 extra cost to the customer if the contractor is using a 50% mark up on equipment costs.

BUT to decide which the 3 ton or the 4 ton? If your furnace does not support a 4 ton, I am not going to quote a 4 ton.

No argument here. The idea I would like you to appreciate is the load calculation may allow a homeowner to reduce the size of the equipment. Consider a homeowner in a climate in the Northeast where summers can be hot and winters are cold, The customer has a 25 year old 4 ton 2-stage condenser which needs to be replaced paired to an 80K BTU 90% AFUE furnace. The customer wants all new equipment and would like to replace it with a 3 ton 2-stage AC with a 60K BTU 95% AFUE furnace to try to save money on the installation costs. Does the contractor say no the builder sized it correctly and that is what will be installed or take a guess based on some rule of thumb and reduce the size the equipment? Larger equipment means the contractor makes more profit, smaller equipment means the homeowner saves money. I think the homeowner would agree to pay for a load calculation if there is an opportunity to save $1000+ in installation costs.

" The measure to being accurate here is again to guess. "

Who wants a contractor of any kind with this attitude? This says it all.