Air Conditioning in Houston

[David]

Originally Posted by red-beard

I have leak frogs

You learn something new every day!

[brainz01]

My condolences. I had to replace my 3 units seven years ago. I planned ahead and had the work done in the middle of winter (February), which kept the cost down. I seem to recall getting a 15 or 20% discount as that's low season. It still cost me $23k. I've heard it's more now.

Can you FlexSeal from the outside of the evaporator? Or even pour some liquid sealant in the pan and let it flow out? Maybe tape the large crack first?

If you do replace, I highly recommend 2 stage variable speed units. The difference in humidity control and comfort is night and day.

Also, not sure if your current unit is r22 or 410a, but the 410a (used by new units) is cheap and readily available. With a good set of gauges it's easy to top off the units ever other year or so.

And yes, always keep a spare capacitor in the correct size, even on new units. Some last forever, others only days - - I actually had one new replacement explode and catch fire...

[red-beard]

There is no access to the internal drip pan, short of cutting holes in the sides of the evaporator box.

I have opened up the drains.

As far as replacement, I am heading towards a true Variable Speed Trane, probably an XV18 or XV20i or Carrier 19VS or 20VS.

[brainz01]

Those are very nice units. I'd suspect they'd be much better at humidity control in the shoulder months - - even on low (stage 1), sometimes my capacity is too high to get long run times in moderate temps and high humidity.

I probably missed it, but how old is the system? Is it still young enough that a new evaporator makes sense?

In my case I knew the old units were toast: 12 year old builder grade R22 and leaking like sieves, and R22 was pricey, not to mention the costvof my time dealing with lots of failures. There was zero sense in throwing thousands at each ubit to keep them going.

Good luck with getting it sorted.

[Tobra]

How about turning the outside of the evaporator box into a drip pan? Flex seal bottom inch or two, put a few shims under one corner and make a drain on the opposite corner.

[SCadaddle]

I just had an HVAC contractor remove my old 3 ton Goodman system and install a new 3 ton Rheem system in my home. The compressor in the 10 year old condenser crapped out and the inside system was 15 years old....so it was time. Interesting enough, the evaporator box and coil was an "Advanced Distributor Products" component, not a Rheem component, and made just up the road in Grenada Mississippi. Just throwing that out here, maybe a solution to be found for your issue.


https://www.adpnow.com/

[Fischer_76_911S]

I had a 17 year old Carrier 2 speed unit that was working flawlessly that I replaced this Jan with a Carrier 20 seer true variable speed drive system. Before you flame me for replacing a working system, let me disclose that I’m in the biz. I thought I had low power bills until this system came along. Absolutely nothing like it. You will never go back to any other type. Hopefully the technology trickles down to the lesser units over the years because it really is a game changer.

Btw, there are rebates right now that may be available in your area.

My 2 cents
Bob

[red-beard]

Originally Posted by brainz01

Those are very nice units. I'd suspect they'd be much better at humidity control in the shoulder months - - even on low (stage 1), sometimes my capacity is too high to get long run times in moderate temps and high humidity.

I probably missed it, but how old is the system? Is it still young enough that a new evaporator makes sense?

In my case I knew the old units were toast: 12 year old builder grade R22 and leaking like sieves, and R22 was pricey, not to mention the costvof my time dealing with lots of failures. There was zero sense in throwing thousands at each ubit to keep them going.

Good luck with getting it sorted.

15 years old originally a York builders grade. The Condenser is 8 years old, RHEEM. I think I've done at least 1, if not 2 main control boards. And sometimes, the air handler/blower squeaks. It was a 13 SEER system, not sure it is doing now with mix of components.

I have no doubt that if I were to put in a 14 SEER system I would see energy savings. My parents put in a two stage system. Their cost is lower, but they have better insulation and they are old and like it about 2 degrees warmer!

Bob:

What would you charge for complete install of two systems, one 3 ton, the other 3.5 ton, with 50KBTU natural gas heaters? Assume the copper line sets do not need to be replaced. Do add in the thermostat upgrades needed.

[cabmandone]

You can pretty much figure they'll replace the line sets when going from 22 to Puron. If you're going from a standard drive to a variable speed indoor and outdoor, the only way to obtain the maximum efficiency is to have the duct system designed for the variable speed system. Anything short of a duct redesign and you don't get full efficiency. If you're selling the place, why are you putting the money in a variable speed system? I don't see recouping the additional cost.

[GH85Carrera]

Originally Posted by red-beard

There is no access to the internal drip pan, short of cutting holes in the sides of the evaporator box.

I have opened up the drains.

As far as replacement, I am heading towards a true Variable Speed Trane, probably an XV18 or XV20i or Carrier 19VS or 20VS.

It sounds like the installer for your AC unit must have been related to the guy that put in the koi pond pump in my back yard. It was all 2.5 inch PVC glued together. No possible repair or replacement of the pump without sawing through the pipes.

I had to dig up some pipe to cut it in a place I could glue on new pieces. I had to completely re-plumb the pump box and filter area. It now has a quick connect fitting to the pump, and I can replace the pump in 5 minutes.

[red-beard]

Originally Posted by cabmando

You can pretty much figure they'll replace the line sets when going from 22 to Puron. If you're going from a standard drive to a variable speed indoor and outdoor, the only way to obtain the maximum efficiency is to have the duct system designed for the variable speed system. Anything short of a duct redesign and you don't get full efficiency. If you're selling the place, why are you putting the money in a variable speed system? I don't see recouping the additional cost.

Im not selling. If I said that, it was meant from being tired of fixing things

[red-beard]

Originally Posted by cabmando

You can pretty much figure they'll replace the line sets when going from 22 to Puron. If you're going from a standard drive to a variable speed indoor and outdoor, the only way to obtain the maximum efficiency is to have the duct system designed for the variable speed system. Anything short of a duct redesign and you don't get full efficiency.

What is different in the duct design for a VSD system versus a single stage?

[Fischer_76_911S]

[/QUOTE]Bob:

What would you charge for complete install of two systems, one 3 ton, the other 3.5 ton, with 50KBTU natural gas heaters? Assume the copper line sets do not need to be replaced. Do add in the thermostat upgrades needed.[/QUOTE]


Quotes vary so much from job to job it's impossible to quote over the phone/keyboard. I flush the copper lines and use a whole tank of Nitrogen purging the system. Unless the lines are short and readily accessible there is really no need to replace them unless they are sized incorrectly.


As far as the comment about ductwork - There is no such thing as sizing for variable speed systems. You size for airflow and constant static pressure. I have designed hundreds of jobs for TVA and Georgia Power as well as hundreds more for "cash" customers. That is how I started in this biz. Variable speed systems generally operate at lower static pressures and will actually push many times harder than a standard system if needed. They usually correct for duct design flaws and the low speed continuous fan settings do wonders for keeping the air moving throughout the house and keeping it filtered while adding roughly a few dollars per month to your power bill.

As far as replacing the system before I sell - it will be 7 years before I sell. Hard to sell a house with a 24 year old system even if it is running perfect, especially when I am in the field. I get the enjoyment, comfort and power savings for 7 years (when I sell) and it will still be under warranty and the low power bills will be a selling bonus. I have over 3400 square feet, a bonus room with 19 windows and two doors (in that 3400 figure) + I am cooling a 28x34 garage with a 42 SEER Carrier ductless mini-split. We are a family of 4 with the washer and dryer always going. My rates are 10 cents per kW/h and my last bill was $95 before all the taxes and "fees" were added. It is so low I wouldn't believe it myself.

My opinion only.
Bob

[Fischer_76_911S]

And yes, they come with their own touch screen communicating stats. Nothing else will work. I also have no horse in this race, just trying to help out a fellow Pelican with a topic I know dear and well.

[cabmandone]

Originally Posted by red-beard

What is different in the duct design for a VSD system versus a single stage?

Variable speed systems are more sensitive to duct design than single speed systems. If you're going to go variable speed, have the static pressure measured to make sure your duct system is adequate for the variable speed system. It has been a long time since I installed a variable speed system but I seem to recall using a different static pressure to design the duct system. The duct system has a pretty big effect on a variable speed system and its ability to reach maximum efficiency.

fisch,
Not saying you're wrong... but variable speed systems do not overcome an improperly designed duct system. They suffer efficiency loss if the system isn't properly designed. Point being, if you're going to spend money on a variable speed system, why not make sure the duct system is designed properly to achieve the maximum efficiency. As a dealer for Carrier for several years, I can tell you with 100% certainty that Carrier would recommend a full duct system evaluation prior to installing one of their infinity systems. They'd also tell you that an infinity system will not reach maximum efficiency without a properly sized duct system.

[aschen]

Our AC units are 18 years old so we will be due soon. It is easy enough to DIY replace caps, fan motors, contactors etc. I am scared of getting fancy new units where i will have to call on skilled tech

[Fischer_76_911S]

Originally Posted by cabmando

fisch,
Not saying you're wrong... but variable speed systems do not overcome an improperly designed duct system. They suffer efficiency loss if the system isn't properly designed. Point being, if you're going to spend money on a variable speed system, why not make sure the duct system is designed properly to achieve the maximum efficiency. As a dealer for Carrier for several years, I can tell you with 100% certainty that Carrier would recommend a full duct system evaluation prior to installing one of their infinity systems. They'd also tell you that an infinity system will not reach maximum efficiency without a properly sized duct system.

Yes, I agree, and sorry to derail this thread. A system is only as good as the duct system. I took a previous post that someone had the impression that the duct designs were different for variable speed heat pumps versus standard single speed units.

A neat feature of the Carrier Infinity line, as you know, is that they will actually do a duct assessment and spit out a calculated duct loss and static pressure and adjust the system accordingly to maximize the performance to what it is hooked up to.

Yes, these systems are going to be far beyond the average DIY’er if something goes wrong. For 99% of my customers, this is not an issue as I get called for clogged traps and the ubiquitous capacitors all the time.

Huge Carrier fan.

[cabmandone]

Not a derail at all. Just good information sharing to help someone make an informed decision before dropping a lot of coin. And yeah Carrier has some impressive tech.