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Discussion Starter · #1 ·
1998 Houston Tx Home, 2 story 1800 up and 1800 down.

Current systems are identical: Rheem 4 ton 13 Seer R22 Condensor and 100K Rheem Critereon 2 stage Furnaces.

Yes and Yes, I know that 4 tons is too much AC per the original manual j done by the builder and the 100K is definitely too much heat.

Quick explanation of why this was done
: When we moved in 1998, the 3 ton units that were installed, were just not getting the job done. Systems were changed out to 4 ton AC and I believe at the time, they had to use a 100K furnace in order to get the 1600 CFM for the 4 ton AC. Much better for our needs and desires. Heating most always runs in low fire.

Fast forward to now and due to the equipment's age and being R22, some current issues in each unit have me looking to replace them. So I am looking for input on multi stage AC and high efficiency multi stage heat. I know nothing about these systems nor do I know what is the best application for their technology. I UNDERSTAND THAT THE MORE BELLS AND WHISTLES THAT THE MORE COMPLICATED THEY CAN BE AND OR EXPENSIVE IN INITIAL COST AND OR REPAIRS.

Brands:
So I am looking at Rheem again, since we had such good luck with the first systems and realize that their newer stuff my not be as good as the older stuff. Second brand choice is Trane, since about 3 years ago my son had a system installed and it has been great for him. (Straight single stage AC and standard 80 furnace.) Also liked this installer and I have no experience with anyone else.

So ask me questions and I will answer.

Thanks

Ed
 

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With low heating needs and having too much heat from 4 ton drive 80 to 100k furnaces, it may make sense to get heatpumps instead.

Gas heat may be cheaper, but for texas heating needs any savings may be wiped out by having to pay a monthly gas service charge.

Don't fixate on brand.

I'm betting 3 ton units didn't cut it due to duct loss or improper charge.
 

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Discussion Starter · #3 ·
With low heating needs and having too much heat from 4 ton drive 80 to 100k furnaces, it may make sense to get heatpumps instead.

Gas heat may be cheaper, but for texas heating needs any savings may be wiped out by having to pay a monthly gas service charge.

Don't fixate on brand.

I'm betting 3 ton units didn't cut it due to duct loss or improper charge.
Is the CFM output for AC and Heat the same in a heat pump?
 

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Is the CFM output for AC and Heat the same in a heat pump?
Heat CFM will be slightly higher. You can also get smaller furnaces that have 4 ton drives in them these days.

Pick your favourite installer. Go with whatever brand he likes. Being in Texas, I definitely would go with a slightly better efficiency unit. Mid range (usually still decent value) will be about 16-18 seer depending on the manufacturer.

Have them check your ductwork too. Bad ductwork and /or duct insulation can cost a fortune in lost efficiency. Especially when the ductwork is in the attic, and a hot climate feels it even more.
 

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You already decided on Rheem.....what's to discuss?
Rheem allows homeowners to purchase directly.
Goodman is another mfg. that allows distributors to sell to homeowners.
There is money to be saved if you know someone who can install and set it up.
And despite the fact that a contractor isn't needs to purchase or install, both of those brands are rated as highly as Trane, Lennox or Carrier.
 

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If the duct work for the second floor is in the attic. Then don't get more than a 2 stage furnace for the second floor. A modulating or multistage furnace in its lowest firing rate won't be moving enough air to get enough throw and mixing to heat the second floor right.

As for A/C, might want to check out the Bosh BOVA.

Texas=dirt cheap gas, so no heat pump. Newer gas furnaces can be gotten in lower BTU sizes with 4 ton drives. Plus, an over sized gas furnace doesn't hurt the heating bill. And if its 2 stage, all the better.
 

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Discussion Starter · #8 ·
Heat CFM will be slightly higher. You can also get smaller furnaces that have 4 ton drives in them these days.

Pick your favourite installer. Go with whatever brand he likes. Being in Texas, I definitely would go with a slightly better efficiency unit. Mid range (usually still decent value) will be about 16-18 seer depending on the manufacturer.

Have them check your ductwork too. Bad ductwork and /or duct insulation can cost a fortune in lost efficiency. Especially when the ductwork is in the attic, and a hot climate feels it even more.
Thanks, I had not received a notification that you responded.
 

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Discussion Starter · #9 ·
You already decided on Rheem.....what's to discuss?
Rheem allows homeowners to purchase directly.
Goodman is another mfg. that allows distributors to sell to homeowners.
There is money to be saved if you know someone who can install and set it up.
And despite the fact that a contractor isn't needs to purchase or install, both of those brands are rated as highly as Trane, Lennox or Carrier.
Thanks for your response, I did not receive a notification that you responded. Actually while it seems I like Rheem because of my past good luck, I am actually open, somewhat.

Thanks for your suggestions.
 

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If the duct work for the second floor is in the attic. Then don't get more than a 2 stage furnace for the second floor. A modulating or multistage furnace in its lowest firing rate won't be moving enough air to get enough throw and mixing to heat the second floor right.

As for A/C, might want to check out the Bosh BOVA.

Texas=dirt cheap gas, so no heat pump. Newer gas furnaces can be gotten in lower BTU sizes with 4 ton drives. Plus, an over sized gas furnace doesn't hurt the heating bill. And if its 2 stage, all the better.
I have both gas heat and a heat pump. Heatpump heat is much more comfortable than furnace heat. That is something to consider. When it gets really cold, gas heat is the order of the day.
 

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Discussion Starter · #11 ·
If the duct work for the second floor is in the attic. Then don't get more than a 2 stage furnace for the second floor. A modulating or multistage furnace in its lowest firing rate won't be moving enough air to get enough throw and mixing to heat the second floor right.

As for A/C, might want to check out the Bosh BOVA.

Texas=dirt cheap gas, so no heat pump. Newer gas furnaces can be gotten in lower BTU sizes with 4 ton drives. Plus, an over sized gas furnace doesn't hurt the heating bill. And if its 2 stage, all the better.

Thanks, was thinking of either a straight 80 or 90 plus single stage heat for the second floor and straight single stage cooling for the second floor. Interesting that you talk about the "throw" since this seems to be an issue with my downstairs! Hmmm after all of these years could a resolve for poor heat exchange downstairs be in the works?

Will look at the Bosch, Yes was looking forward to reducing these heater from 100K because I know they are oversized and now with 4 ton drives having lower heating BTU's it will work out.

I was also thinking that since the downstairs is our main living area now that kids have moved on, I would at least 2 stage the cooling downstairs for more comfort and single stage the heat for better throw. Upstairs would be single stage cooling and heat via ECM.
 

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If the duct work for the second floor is in the attic. Then don't get more than a 2 stage furnace for the second floor. A modulating or multistage furnace in its lowest firing rate won't be moving enough air to get enough throw and mixing to heat the second floor right.

As for A/C, might want to check out the Bosh BOVA.

Texas=dirt cheap gas, so no heat pump. Newer gas furnaces can be gotten in lower BTU sizes with 4 ton drives. Plus, an over sized gas furnace doesn't hurt the heating bill. And if its 2 stage, all the better.
How much heating is needed in texas though?
I can't imagine much at all.
What about the monthly gas meter charge?
 

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Discussion Starter · #13 ·
How much heating is needed in texas though?
I can't imagine much at all.
What about the monthly gas meter charge?
Heat in Texas, most likely not a lot. But BT has hit a nail on the head about "throw" that could be an answer to a long term problem we have had downstairs. That coupled with a ceiling return only has caused the downstairs to always feel cold and not the usual heat turn over when the heater comes on.

My house is a large 2 story 1800 up and 1800 down and has NEVER felt comfortable heat wise, especially downstairs with 8' ceilings. Another issue downstairs is that they placed the return air in the ceiling. A good friend of mine, now passed, who owned his own HVAC business once tested the issue with the return by attaching a flex duct from the ceiling to the floor. We ran it that way for several days and drawing the cool air from down low brought the warm air down making a better comfort feeling. We were never ever able to figure out a redesign of the return air: move from ceiling to lower wall.

My costs for gas which include 2 40 gal water heaters and gas dryer is approximately 30-130 during winter months. Even on the higher end when colder, the house never seems warm when the heater comes on.
 

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Heat in Texas, most likely not a lot. But BT has hit a nail on the head about "throw" that could be an answer to a long term problem we have had downstairs. That coupled with a ceiling return only has caused the downstairs to always feel cold and not the usual heat turn over when the heater comes on.

My house is a large 2 story 1800 up and 1800 down and has NEVER felt comfortable heat wise, especially downstairs with 8' ceilings. Another issue downstairs is that they placed the return air in the ceiling. A good friend of mine, now passed, who owned his own HVAC business once tested the issue with the return by attaching a flex duct from the ceiling to the floor. We ran it that way for several days and drawing the cool air from down low brought the warm air down making a better comfort feeling. We were never ever able to figure out a redesign of the return air: move from ceiling to lower wall.

My costs for gas which include 2 40 gal water heaters and gas dryer is approximately 30-130 during winter months.
Cooler supply air in heating can help with mixing.
Low level return is quite important when vents are on the ceiling, so it will never be perfect without.

If you end up with furnaces, seek units with low rated temperature rise ranges.
Not that I'm fond of goodman, but they make a 60k 80% with a 4 ton drive, 20-50f temp rise range. (ss-gmes80_gces80abbb4c0022fa6258827eff0a00754798)

The 80% furnaces are for more southern climates and have lower btu output relative to input - more blower capacity relative to heat output.
For 90%+, to my knowledge need to buy a 80k btu (75 to 58k output) to get 4 ton drive.
 

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I would highly suggest going for the 2 stage heat. Go as low as you can on the furnaces. The longer runtimes really help mix the air. Most mid tier units have more options for adjusting airflow. Higher low stage heating airflow will help mixing. You'll just have to pick a setting that doesn't feel drafty.

The oversized furnaces can really make the just uneven and feel cold in places.

Ground floor really should have had low returns. If you can figure that out, it'll make a big difference.
 

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Before you go off and dump a lot of money into the economy. I would reconsider.

Furnaces are rated in BTU's then you have to take the efficiency into account.
100,000 BTU furnace that is 80% efficient is an 80,000 btu furnace. Number chosen to make it easy.
There is nothing wrong with R-22, it is just expensive. It can still be purchased. I ripped my R22 system out 4 years ago and discovered that the new R410a is not any better. Oh the days of R12. I found that after I got my A coil out the inside of the coil was dirty. If I had done a good cleaning I could have saved $3500 in equipment. Yes the inside of the coil, pain in the ass to get to but possible.
A better than average tech can evaluate your system and find the flaws in it when compared to what is available today.
Since you in the SW you will not be able to buy anything less than 14-15 seer. Which is a joke to use as a comparison tool. It is not about the equipment it is about how your house feels. The amp draw will go down a bit the higher the seer. Mine went from 23 amps to 19. Electric bill stayed the same.

All MFG's build to a price point. Between the MFG's there is very little differences in the equipment in the class. Choose something that has a great, not good, local parts stock.

Multi speed units for new construction and a very tight home maybe. Retrofit, save your money. You need a better than average equipment installer to apply high tech equipment.
The installer is the MOST important part of this equation.

I choose VFD's on my air handler. I do so because the stock programing goes a long way to handle the humidity in my home. Humidity causes health issues for me. (desert dweller so I can breathe) If not important to you then you can go with something less expensive.
I would be interested in air filtration in the new equipment. A way to keep the home cleaner is always a good idea. Cheaper when done on the install.

Back up heat might be a good idea, but only if you have an alternate source of power. (generator installed correctly as back up) My family in Paris, TX were pretty chilly last winter.
They have several fireplaces and wood stacked outside.

Lastly where the equipment is located and the area around it is very important. Sizes of the equipment has changed. Mine was narrower and shorter than what I replaced.
Split systems have line sets, if in good condition these can be cleaned. If not clean correctly can be a problem. Mixing freon is not a good idea.

I personally will not own a vehicle with ONSTAR nor will have have my computer on wireless.
I am old school when it comes to security. OFF is impossible to hack.

I am building a new home and chose 2 inverter mini splits for it. Lots of differences and no duct work install. Besides the rated noise from the minis is less than what I have now.
 

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I have both gas heat and a heat pump. Heatpump heat is much more comfortable than furnace heat. That is something to consider. When it gets really cold, gas heat is the order of the day.
I think you'll find at least as many people that will tell you that gas heat is far more comfortable then a heat pump. Its a personal preference/comfort think. Not something that holds true for everyone.
 

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Discussion Starter · #18 ·
Can someone speak to multi stage AC systems? Their operation compared to a single stage that we are use to?

Thanks
 

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Multi stage, or 2 stage?
 

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The lower the capacity it can run at, (2 or more stages) the longer it runs. Preferably indefinitely. It mixes air better, but you also have less aggressive temperature swings. That holds true for gas heating, cooling, or heat pumps, etc.
 
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