Just bought a house here in central Florida - so we're going to be using our AC a LOT more than in TN.  1350 sq. ft. home, new roof, ceiling fans throughout.  Quite a few windows as well.

The current AC unit works, but I'm wondering if spending the money to replace it with a new, more efficient unit would save me enough to eventually justify the extra expense.

Stats on current unit:

2.5 Ton self-contained AC system with 2.5 ton heat pump system, 10.5 SEER rating.

At least you have a heat pump.  We looked into one, it's big money up front, but long-term it s way cheaper.  I'm no HVAC technician, but I'd leave it alone if it works... it couldn't be that inefficient with a heat pump.

ETA: Add insulation... it's a royal PITA (read: itchy), but it's cheap and it's likely to pay for itself in less than a year assuming you do it yourself.

Quoted: Just bought a house here in central Florida - so we're going to be using our AC a LOT more than in TN.  1350 sq. ft. home, new roof, ceiling fans throughout.  Quite a few windows as well. The current AC unit works, but I'm wondering if spending the money to replace it with a new, more efficient unit would save me enough to eventually justify the extra expense. Stats on current unit: 2.5 Ton self-contained AC system with 2.5 ton heat pump system, 10.5 SEER rating.

Leave it alone... dont fix what is NOT broken. 10.5 is NOT bad.

Quoted: Just bought a house here in central Florida - so we're going to be using our AC a LOT more than in TN.  1350 sq. ft. home, new roof, ceiling fans throughout.  Quite a few windows as well. The current AC unit works, but I'm wondering if spending the money to replace it with a new, more efficient unit would save me enough to eventually justify the extra expense. Stats on current unit: 2.5 Ton self-contained AC system with 2.5 ton heat pump system, 10.5 SEER rating.

2.5 is plenty for that sq footage.. as is the heat...

if it runs fine leave it..unless you want to drop  2-3000$ to replace it! cuz thats what its gonna cost you if not more!

Check out the roof decking from the inside (ie, look at it from the attic).  Is it a "cool ply" type decking?  If not, you can go to Sherwin-Williams and buy radiant barrier pant and spray paint the inside of the roof decking.  I did this an it dropped the attic temp about 30 degrees.  If you have cool ply, you are good to go on that front.

Thanks, guys.  God knows I've spent thousands in the past on other houses (new insulated windows, insulation, doors, new AC units, etc.) and haven't noticed that big of a difference (maybe $10-$15 a month) in my bills.  Not exactly a good return on investment.

No-one on a web forum is going to be able to tell you if you should replace the unit from a simple description.

The real questions are: What is the apparent age of the condensing unit, how does the external appearance, {dents, rust, etc} how well does it work. {fan noise, temp drop before/after evaporator coil during operation}

To read some of the criteria of a/c operation read this home or office "do-it-yourself" air conditioning guide. www.longviewweb.com/do_it_yourself.htm

If you should decide that you’re a/c may only last a couple of years more, the time to replace it is NOW.

The national efficiency standard for central ACs took effect in 1992, requiring a minimum SEER of 10. New standards, set to take effect in 2006, will raise the SEER requirement to 13, an improvement of 30% relative to 10-SEER units. These more efficient systems ultimately will save homeowners money on utility bills and help to conserve energy. But air conditioner manufacturers estimate that the price of the new units will be 30% to 50% higher -- with the cost passed on to the consumer.

Homeowners may grapple, though, with how environmentally conscious they should be. Should you save money by installing the current SEER 10 system, or pay more for a more energy efficient unit that is cheaper to operate over time? The quandary is similar to one in the early 1990s when homeowners were ordered to install low-flow toilets that use 1.5 gallons of water per flush compared to the then-standard 3 gallons. Many refused to give up the larger tanks, and rushed out to buy more.

According to Gary Marowske, president of Flame Heating, Cooling & Electrical in Warren, replacing an average SEER 10 central air conditioner costs $2,500 to $3,500. For each SEER upgrade -- there are 11, 12, and 13s already being sold locally and nationally -- the cost increases $400 to $600. So under the new mandatory guidelines, a homeowner could pay an additional $1,200 to $1,800 for a new SEER 13 system.

Before replacing the unit:

Have your contractor perform a complete load calculation (called a "Manual J" calculation) to make sure you get a properly sized unit. An oversized central AC will cycle on and off too often, impeding its ability to control humidity.

Make sure that all of the components of your new system are designed to work together. In addition to the large outdoor unit (the condenser and compressor), your contractor should replace the indoor unit (the blower coil), and, if necessary, even the thermostat. Your system will work best if all the pieces take advantage of advances in product design and are matched to each other.

For efficiency when it is needed most (on the hottest days), be sure that the unit has a TXV (thermal expansion valve) plus an EER (high temperature rating) greater than 11.6. Ask your contractor to provide details on the models that you are considering or check the CEE Directory of ARI Verified Equipment to make sure that the combination of condenser and indoor unit your contractor has proposed meet the efficiency levels recommended by the Consortium for Energy Efficiency.

A variable speed air handler will improve comfort and efficiency and allow continuous air filtering at minimum energy cost.

Have your contractor check that all supply and return systems balanced.

Attic fan.
More insulation.

Quoted: No-one on a web forum is going to be able to tell you if you should replace the unit from a simple description.

But that sure won't stop them from having opinions.

Quoted: Quoted: No-one on a web forum is going to be able to tell you if you should replace the unit from a simple description. But that sure won't stop them from having opinions.

Opinions are like assholes, everyone should have one.
If you don't, then you are full of shit.

Quoted: No-one on a web forum is going to be able to tell you if you should replace the unit from a simple description. .

Sure you can. Its like asking "What should I have to eat" ...first you have to pass the criteria of "Am I hungry or not?" In this case, you have a working unit...LEAVE IT ALONE! someone already has done the heat load calculations to install it in the first place....; and it works.

Its not a technical question. Its a common sense question so to answer your statement... YES it CAN be answered on the web.

Quoted: Attic fan. More insulation.

THIS is gospel! and if I may add one more thing... double pane windows.

Quoted: Quoted: No-one on a web forum is going to be able to tell you if you should replace the unit from a simple description. . Sure you can. Its like asking "What should I have to eat" ...first you have to pass the criteria of "Am I hungry or not?" In this case, you have a working unit...LEAVE IT ALONE! someone already has done the heat load calculations to install it in the first place....; and it works. Its not a technical question. Its a common sense question so to answer your statement... YES it CAN be answered on the web.

Read my second sentence ABOVE before posting again.

Sooo, since you are clairvoyant, tell me how MY a/c is working. Mr. Smart "Cookie"
How loud is my condensing fan? Has it blown a capacitor recently?
What is my temp drop? Is my suction line sweating on a humid day?

How deep is his attic insulation? Do you know IF he he even has single pane windows? Since you want him to pull out what may be double pane windows What is the energy difference/cost between newer double pane windows and his?

Someone has already done the calculations huh? WHO? A do-it-yourselfer? The house contractor who may have cut cornors? That's why my parent's central a/c worked so well when the house was built new. The contracter put in the smaller rated unit than was advisable.

Our HVAC guy told us that in 2006, the Fed requirements for SEER ratings, coolant types, etc., are going to change enough that every new or replacement AC/Heat unit will double in cost.

He says do it NOW.

Preferably in Oct/Nov when his work load is lighter.

And he is our friend, not an opportunistic HVAC vulture.

Do it NOW, it will cost a LOT more later.

Quoted: Quoted: Just bought a house here in central Florida - so we're going to be using our AC a LOT more than in TN.  1350 sq. ft. home, new roof, ceiling fans throughout.  Quite a few windows as well. The current AC unit works, but I'm wondering if spending the money to replace it with a new, more efficient unit would save me enough to eventually justify the extra expense. Stats on current unit: 2.5 Ton self-contained AC system with 2.5 ton heat pump system, 10.5 SEER rating. Leave it alone... dont fix what is NOT broken. 10.5 is NOT bad.

Wise advice!  

Quoted: Our HVAC guy told us that in 2006, the Fed requirements for SEER ratings, coolant types, etc., are going to change enough that every new or replacement AC/Heat unit will double in cost. He says do it NOW. Preferably in Oct/Nov when his work load is lighter. And he is our friend, not an opportunistic HVAC vulture. Do it NOW, it will cost a LOT more later.

jan 06'   they go to 13 seer.....


perosnally i stay outta  most of these  "" ohh my a/c dont work hive mind save me"" threads.... to many shade tree know it alls,,..

I never said I know what his situation is and I read your comments above. I have been in the HVACR industry for over 20+ years and I can tell you that in my journeys I have turned away MANY jobs because the unit is working 100% and because someone put the SEER bug in the customer's ear, they are ready to spend a crap load of money where they didnt need to.

Not much to AC work to know that if the unit is working, leave it alone. I have had too many customers have units changed out to a higher SEER rating only to say "Wow. all that money I spent to change the unit out and this is ALL I save?... what a rip"

About the windows, insulation and attic fan, They are SUGGESTIONS and NOT ORDERS.

My qualifications?

--AS I said 20+ years in the HVAC business
--Technical Advisor to a Major manufacturer on quality and servicability issues
--Troubleshooter to a High end refrigeration company when other companies cannot repair the problem, they call me.
--Installed more units than I care to remember
--Own my own refrigeration company.

So do I qualify?

Quoted: Thanks, guys.  God knows I've spent thousands in the past on other houses (new insulated windows, insulation, doors, new AC units, etc.) and haven't noticed that big of a difference (maybe $10-$15 a month) in my bills.  Not exactly a good return on investment.

Trees?

The house currently has a new roof, roofer said insulation looked pretty good and thick.

Not much shade, though.

Most of the windows are single pane crank-style Florida windows, though there are a couple of double-paned double-hung windows up front.

However, I would think it would probably be a good idea to have the AC and blower professionally inspected and serviced (yearly tune-up), right?  Pretty cheap, and I'll know it is operating at peak efficiency.

Not yet ready to spend a ton of cash on new windows, AC, etc. for a possibly lower energy bill.

every new or replacement AC/Heat unit will double in cost.

It's even worse than that.  I manage about 150 apartments and houses part-time, and the quote I got for our replacement cost on Trane compressors was three times what we're paying now.   We're buying a dozen compressors before the end of the year because of the huge price increase.

The contracter put in the smaller rated unit than was advisable.

They always do that so then they'll be back out in a summer or two to make even more money off of you.

To the original poster, does your current unit keep the house cool?  If so, don't worry about doing anything.  If you're like most people and it doesn't, then let us know how poorly it performs.z

Welcome to the latitudes of heat. Once you have plenty of insulation make Solar screens for your windows. They are without a doubt the most bang for your buck. Solar screens replace the outside window screen with a one piece screen of woven sunshade cloth. Use window screen frame and spline to complete. They also add a cool look to the house if you get the right color fabric.

Quoted: Just bought a house here in central Florida - so we're going to be using our AC a LOT more than in TN.  1350 sq. ft. home, new roof, ceiling fans throughout.  Quite a few windows as well. The current AC unit works, but I'm wondering if spending the money to replace it with a new, more efficient unit would save me enough to eventually justify the extra expense. Stats on current unit: 2.5 Ton self-contained AC system with 2.5 ton heat pump system, 10.5 SEER rating.

Some day it will pay for itself but depending on how much you run the unit will dictate when that will be....

Quoted: I never said I know what his situation is and I read your comments above. I have been in the HVACR industry for over 20+ years and I can tell you that in my journeys I have turned away MANY jobs because the unit is working 100% and because someone put the SEER bug in the customer's ear, they are ready to spend a crap load of money where they didnt need to. Not much to AC work to know that if the unit is working, leave it alone. I have had too many customers have units changed out to a higher SEER rating only to say "Wow. all that money I spent to change the unit out and this is ALL I save?... what a rip" About the windows, insulation and attic fan, They are SUGGESTIONS and NOT ORDERS. My qualifications? --AS I said 20+ years in the HVAC business --Technical Advisor to a Major manufacturer on quality and servicability issues --Troubleshooter to a High end refrigeration company when other companies cannot repair the problem, they call me. --Installed more units than I care to remember --Own my own refrigeration company. So do I qualify?

If those are really your qualifications. . . .
However, instead of calling me out because I thought we needed more information, a professional could have asked a simple professional question such as this:

Quoted: To the original poster, does your current unit keep the house cool?  If so, don't worry about doing anything.  If you're like most people and it doesn't, then let us know how poorly it performs.z

An answer to that is going to begin telling us something. Though, we still don't know if the a/c runs hours to maintain a comfortable temperature.  Just because something works doesn't mean it runs well.

Since you are a professional, I'll wait to see if you give some easy suggestions that a normal homeowner can use to determine whether his system is running efficiently.

We only learned 11/2 hours after the first post that Greywolf2112 has some single pane windows.

Quoted: The house currently has a new roof, roofer said insulation looked pretty good and thick. Not much shade, though. Most of the windows are single pane crank-style Florida windows, though there are a couple of double-paned double-hung windows up front. However, I would think it would probably be a good idea to have the AC and blower professionally inspected and serviced (yearly tune-up), right?  Pretty cheap, and I'll know it is operating at peak efficiency. Not yet ready to spend a ton of cash on new windows, AC, etc. for a possibly lower energy bill.

So DrFrige, you now know more. Greywolf2112 probably has enough insulation. And he is not going for a windows replacement project. So be a professional and give him a short list of things he can do do lower cooling costs with money-saving tips.  AND there's an answer to Greywolf2112's curiosity if >>"a new, more efficient unit would save me enough to eventually justify the extra expense."<<  The answer isn't always NO! and depends on a little math.

If you need some help, getting Greywolf2112 information, you can google it.

Oh, and in the future, make a mental note not to fire a shot across someone's bow when they're trying to help, instead of offering constructive help yourself!  

Quoted: Quoted: I never said I know what his situation is and I read your comments above. I have been in the HVACR industry for over 20+ years and I can tell you that in my journeys I have turned away MANY jobs because the unit is working 100% and because someone put the SEER bug in the customer's ear, they are ready to spend a crap load of money where they didnt need to. Not much to AC work to know that if the unit is working, leave it alone. I have had too many customers have units changed out to a higher SEER rating only to say "Wow. all that money I spent to change the unit out and this is ALL I save?... what a rip" About the windows, insulation and attic fan, They are SUGGESTIONS and NOT ORDERS. My qualifications? --AS I said 20+ years in the HVAC business --Technical Advisor to a Major manufacturer on quality and servicability issues --Troubleshooter to a High end refrigeration company when other companies cannot repair the problem, they call me. --Installed more units than I care to remember --Own my own refrigeration company. So do I qualify? If those are really your qualifications. . . . Yes they are and if you have been here since 4/01 You KNOW that they are However, instead of calling me out because I thought we needed more information,I NEVER called you out. a professional could have asked a simple professional question such as this: Quoted: To the original poster, does your current unit keep the house cool?  If so, don't worry about doing anything.  If you're like most people and it doesn't, then let us know how poorly it performs.z An answer to that is going to begin telling us something. Though, we still don't know if the a/c runs hours to maintain a comfortable temperature.  Just because something works doesn't mean it runs well. Since you are a professional, I'll wait to see if you give some easy suggestions that a normal homeowner can use to determine whether his system is running efficiently.I will NOT give you any professional suggestions. You are the FIRST person on ARFCOM I am denying ANY free advice for. I only help those that have asked nicely and appreciated it. We only learned 11/2 hours after the first post that Greywolf2112 has some single pane windows. Quoted: The house currently has a new roof, roofer said insulation looked pretty good and thick. Not much shade, though. Most of the windows are single pane crank-style Florida windows, though there are a couple of double-paned double-hung windows up front. However, I would think it would probably be a good idea to have the AC and blower professionally inspected and serviced (yearly tune-up), right?  Pretty cheap, and I'll know it is operating at peak efficiency. Not yet ready to spend a ton of cash on new windows, AC, etc. for a possibly lower energy bill. So DrFrige, you now know more. Greywolf2112 probably has enough insulation. And he is not going for a windows replacement project. So be a professional and give him a short list of things he can do do lower cooling costs with money-saving tips.  AND there's an answer to Greywolf2112's curiosity if >>"a new, more efficient unit would save me enough to eventually justify the extra expense."<<  The answer isn't always NO! and depends on a little math. If you need some help, getting Greywolf2112 information, you can google it. Oh, and in the future, make a mental note not to fire a shot across someone's bow when they're trying to help, instead of offering constructive help yourself!  I NEVER fired a shot... YOU did.

Wow, I seriously didn't expect my post to start a minor shitstorm.  Sorry about that, guys.

I won't know until I've been in the house (I close on Tuesday) for a while what the bills are like and how much it runs.  Seems to cool the house well, but I haven't been in there for more than 30 minutes at a time yet.

Thanks for the suggestion on the solar screens.  Will have to look that up.

I'm also going to have the local utility come by and do an energy audit as well to see what can be done to better insulate and weatherproof the house.

About 2 years ago, I replaced my worn out, constantly breaking down electric heat pump with a new unit, electric as well. My old unit was about 17 years old and the best we could tell the SEER rating was about a 8. The new unit was the same tonnage but the SEER rating was about a 12 to 12.5 as I recall. I do balanced bill pay on my electric bill so every month it is the same. I saved about $25 a month from my old unit by going to the newer unit. I did not add any insulation as I did not need to.

Quoted: About 2 years ago, I replaced my worn out, constantly breaking down electric heat pump with a new unit, electric as well. My old unit was about 17 years old and the best we could tell the SEER rating was about a 8. The new unit was the same tonnage but the SEER rating was about a 12 to 12.5 as I recall. I do balanced bill pay on my electric bill so every month it is the same. I saved about $25 a month from my old unit by going to the newer unit. I did not add any insulation as I did not need to.

May I ask what did you pay for the new unit?

It is an Amana with scroll compressor and is a 3 ton electric unit. As I recall, I paid about $3500 installed. They also removed my old unit and hauled it off. That also included a digital thermostat, which is the finest thing since sliced bread by the way.

I compared this unit to about 5 or 6 others by 3 other contractors. A friend of mine had some Amana units installed and highly recommended them.

Quoted: It is an Amana with scroll compressor and is a 3 ton electric unit. As I recall, I paid about $3500 installed. They also removed my old unit and hauled it off. That also included a digital thermostat, which is the finest thing since sliced bread by the way. I compared this unit to about 5 or 6 others by 3 other contractors. A friend of mine had some Amana units installed and highly recommended them.

Digital Thermostats are the way to go... They also have a delay safety feature that protects compressors believe it or ... They delay the restart of a compressor by 5-10 minutes so the pressures can equalize... Nice move!

reason I was asking about the price is to show that the price recovery of your unit of 3500.00 and a savings of 25.00 on your electric bill can take up to 140 months. Now your old unit was breaking down a lot so it is WAY worth it to do what you did.

Thank you sir!

About the last 3 to 4 years I had the old unit, I was paying about $200 to $400 a year in maintance at the change of the seasons. What finally made my mind up was when I was without heat for about 5 days and the temps made it down into the 20's and the absolute warmest I could get the house during the day was 60, that is cold even for me. Basically, I was slowly re-building my old unit and the compressor was about crapped out along with some other major parts. The heating strips were completely gone and even after they were replaced the little ceramic washers that they are inside of were completely shot and cracked and fell apart. Going for several days in the summer with no air and several days in the winter with no heat was NOT cutting it. I got my moneys worth out of the old unit.


ETA: Not to mention the days I had to leave work early waiting on a repair guy. You know the spiel, "he'll be there between 10 and 4, so someone has to be there." I absolutely HATE that shit.

Quoted: Wow, I seriously didn't expect my post to start a minor shitstorm.  Sorry about that, guys.

No Greywolf2112; YOU do not have to apologize for anything.

DrFrige and I do.
--------------------------------------------------------
POST EDITED:

DrFridge and I have exchanged IM's late Sat night.
DrFridge realizes that when he wrote the first picayune comments towards fnbrowning, that he stopped being helpful to Greywolf2112, to become plainly critical of another ARFCOM member who was just giving assistance.

And I of course took the bait, which led to the:


I believe the whole thing can end here/now. Any post after this concerning DrFridge/fnbrowning is not helpful.


And now I'm done having fun.

From what I have read YOU were the first one to mouth off to him. So everyone just drop it and go back to what this thread was about....

Quoted:

Tag.

Looking at possibly replacing my ac unit as well.......

Thanks for the info guys.

Can't we all just get along?

I lived and worked in SW Fla.  The HVAC issue we had where I worked was maintenance.  The dewpoint is ridiculous (in my opinion...I know people who love it), and the bugs are nasty.  One of my duties was to hose out the condensers to keep them from getting clogged with bugs.  The boss also showed me BOTH condensate drains and explained that one was from the regular drain connection and that line should have water coming out of it, and the emergency pan drain that should NOT have water coming out of it.  Even my house had another pan under the inside unit.  In case the drain gets clogged, the condensate will be caught by the emergency overflow pan and not ruin the ceiling drywall until you can get the main drain working again.

Took me a long time to get used to the noise of the tree frogs hitting my windows at night.  Thought someone was throwing stuff at the house.  

Quoted: I lived and worked in SW Fla.  The HVAC issue we had where I worked was maintenance.  The dewpoint is ridiculous (in my opinion...I know people who love it), and the bugs are nasty.  One of my duties was to hose out the condensers to keep them from getting clogged with bugs.  The boss also showed me BOTH condensate drains and explained that one was from the regular drain connection and that line should have water coming out of it, and the emergency pan drain that should NOT have water coming out of it.  Even my house had another pan under the inside unit.  In case the drain gets clogged, the condensate will be caught by the emergency overflow pan and not ruin the ceiling drywall until you can get the main drain working again. Took me a long time to get used to the noise of the tree frogs hitting my windows at night.  Thought someone was throwing stuff at the house.

Nah Fla is NOT a place I wanna live... I HATE bugs and I have seen those huge ass roaches... NO THANKS!!!... But what is the deal with the tree frogs hitting the window all about??

Don't want to hijack Greywolf's thread so I'll try to keep it brief.  I think the tree frog is nocturnal.  They like bugs.  I'm in the house with the lights on and the bugs would hang around the outside of the windows.  The tree frog would jump and land on the glass, and would stick to it.  I had some high windows that were about 8 feet off the ground and those suckers could hit those.

tree frog

The 'love bugs' are another treat. love bugs

"window" a/c units were the worst.  My guess is they drain the condensate to the rear of the unit to be evaporated by the condenser fan.  Bugs and algae and crap plugs them up and water starts running out either inside or outside.

DrFrige
                   I have a Question,  I am building a new 2 story house about 1800sq. feet.  Now the A/C heating contractor has suggested a unit that is a A/C and Heating all in one unit that sits outside,  And has the Condenser/air handler under the house and use's insulated ducting through the house. If you are familiar with these units what do you think of them. I and looking at the Goodman brand unit.
                                  thanks for the help
                                               tucker

Quoted: DrFrige                    I have a Question,  I am building a new 2 story house about 1800sq. feet.  Now the A/C heating contractor has suggested a unit that is a A/C and Heating all in one unit that sits outside,  And has the Condenser/air handler under the house and use's insulated ducting through the house. If you are familiar with these units what do you think of them. I and looking at the Goodman brand unit.                                   thanks for the help                                                tucker

I have a Goodman unit myself... Not "Thrilled" with it.. I only got it because my supplier had one and  it was cheap and worked good. Right off the bat I had the condenser fan motor miswired and that was not a good sign. I fixed that and then had issues with two blown capacitors over 6 years and a contactor fail... not good... Plus the neighbors HATE the condensing unit noise outside. I am inside so I dont hear it.

I dont know the layout of your home so I dont know how practical the evaporator air handler 'under' a house would be. I have never seen it done that way. Seen them in closets, attics and basements... never seen them under a house. Are you talking in a crawlspace? If you are I would think of the servicer and the accessability.

Hindsight I should have looked into Lennox or Trane. Yes they are more but you want to get the most out of your money. Get yourself a few other estimates and CALL the manufacturers and ask them who the BEST servicer is in your area. Many times they cant tell you because it is playing favoritism so ask the CS rep, If YOU were building a home, who would you recommend. sometimes they will hint to you who is the best.

Sorry I wish I could be of more help

oops double post

If anyone needs help with plans for solar screens please email me. I can give you materials lists and connections for the screen material. I cant stress enough how much difference they make.

Another question - how difficult is it to install a digital, programmable thermostat on this puppy of mine?  I think it is a 2-stage unit.  I've done this before, but I think it was a single stage unit.

Perhaps I could get a AC service company to come and do a yearly PM on the unit, test it, etc. and have them install the digital thermostat.  Sound like a good idea?

Quoted: Another question - how difficult is it to install a digital, programmable thermostat on this puppy of mine?

Very, very simple

Quoted: Another question - how difficult is it to install a digital, programmable thermostat on this puppy of mine?  I think it is a 2-stage unit.  I've done this before, but I think it was a single stage unit. Perhaps I could get a AC service company to come and do a yearly PM on the unit, test it, etc. and have them install the digital thermostat.  Sound like a good idea?

Do it yourself. I charge $100 to wire in a stat id you provide it, over $200 if I provide it.

With a heat pump you will have terminals labeled on the back or inside of the old stat. R,C,G,O,E,W,Y ......  "E" may also be labeled W2.

WRITE DOWN the letters and what colors they go to and hook up the new one the same way.

Well, I figured after 13 years of hard Florida use, it was going to be time to upgrade.  And I was right.  Had an AC guy come out from a very reputable company today to do a service/tune-up/safety check.  Former Marine and a nice guy, so I had no reason to not trust him.  We checked everything out and the current unit had a frozen up exchanger (?) and the compressor had a slow leak.  Rusted like hell, too.  Air handler was full of mold, and some of the ducts were leaking.  Also it only had one return (should have two for this house).

So, since the new SEER laws are going into effect in January, I figured I might as well replace the system now with a 11 SEER while I can at a decent price.  Got the new unit, digital talking thermostat, duct repair, new air handler/furnace, new return in the back of the house, new drain lines that are up to code (mine weren't), new electrical fixtures, and a light in the attic (also needed by code) plus a $250 lifetime filter, 0% financing for 12 months, etc. for $4800.

Calling around, it is a fair price, and comes with a nice warranty.  Probably could have shopped some more, but this is a local company, 38 years in business, VERY professional and courteous and on-time (and I will pay extra for that).