Heating, Air Conditioning, Fridge, HVAC/Split system vs heat pumps

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Question
I live in SW Florida where day time temps reach 100F in the summer months and 70F-90F in winter months. It can get down into the upper 20's to low 30's night time temps on rare occasion. My home was built in 2007 2400sq ft with 1580sq ft under roof that is A/C and Heated. My current system is a Rheem Classic Series 3 ton 13 seer with a 10KW heat element...Model #RHSA-HM3617JA.

I was told the unit is contractor grade, 5 year parts warranty on everything, 10 year on the compressor. I'm being told newer upgrade systems carry 10 years across the board. I had to replace the outside condenser fan in 2010. This week I had to have 106 oz of R-22 put in as the system kept freezing up. I'm told something is leaking however, the cost to find the leak is a little prohibitive given the age and life expectancy of the unit. I'm told 10 years in Florida is a fair life expectancy for any HVAC unit given the fact they run 24/7 365 days a year.

MY QUESTION: Is a split system a better choice over a heat pump? My mother and brother both have heat pumps and the only difference I'm seeing is I can get my A/C down to 70F and my heat up to as high as I'd like.....probably 90F?? There heat pumps seem to do a great job at A/C but short on the heat side. Would just like an opinion and any suggestions you might offer. Thanks

ANSWER: Dennis,

Sounds like you have straight A/C with a Air Handler with electric heat strips for heat. 10 KW . I would go with a Heat Pump and get a new air handler wit a 10 KW heat element. Put an outdoor t-stat ( located inside the outdoor unit ) and set it for 30-35 degree. anytime your 2nd stage heat calls   it will not energise the heaters until the OD temperature goes below 30-35. Your first stage would be your Heat Pump. You would have to change the existing indoor unit and electric heaters, outdoor unit and interconnecting line set. The new refrigerant is R 410A and runs at up to 60 % higher pressures than R22, so you cannot use the indoor coil. The line set may have residual mineral based oil and would need to be replaced as the new units use a different type of compressor oil ,and the oils do not mix. If your line set runs through an exterior wall and cannot be replaced, you would need to flush out the line set.

A typical 3 ton Heat pump outdoor unit runs at 8-10 amps. a 10 KW electric heater draws 38-40 amps. So clearly the HP is more efficient than running straight electric.

10 year all parts warranty is standard ,but there are better warranties than that, if warranties area a high consideration for you when purchasing a new system.  Amana has a whole outdoor unit replacement if the compressor fails. They also have a lifetime compressor warranty ( both apply to the original owner only ) Goodman ( a value line brand ) has the 2nd best warranty. Actually Goodman is the Company that started the 5 year compressor 5 years parts when other Companies were offering one year parts five year compressor, when the Competitors matched Goodman, they went one better and where the first to offer the 10 years compressor 10 years parts. They also offer a lifetime compressor warranty, the higher you go in SEER rating. Most other manufacture flat line or only go slightly higher after 10/10 warranty even when you go up in SEER.

Whatever brand you decide get all your warranties in writing, including the labor. Even the t-stat if that is going to be replaced. Chances are your current circuit breaker for the outdoor unit is going to be oversized ( rating wise )for the newer more energy-efficient units of the same tonnage. It will state on the electrical data plate on the outdoor unit the maximum overcurrent amprege size . If that is the case ,you need to have it replaced. The indoor breaker should be OK.

The installation and proper refrigerant charging ,correct ductwork, proper static pressure set up is the key to a dependable trouble free system not name brand. Having unit PM serviced over the years helps also.  All manufactures make very few of their own parts. Of a total Central A/C Heat Pump in a residence, probably only up to 10-15 % parts is made by any manufacture. The ductwork and grilles alone is probably upwards of 50 % of the system and that's installed by local Contractors.

---------- FOLLOW-UP ----------

QUESTION: I'm replacing both the air handler and the outside unit of the split system. My technician thinks the leak is more likely than not in the evaporator coils. I have a very good understanding of automotive A/C and have repaired many but residential A/C is a whole different tune that I basically understand components but not familiar with what can go with what. My technician informed me they just pull out the old air handler and put the new one in and usually get away with little or no modification. Being my consideration for a split unit would be Carrier over Rheem it seems a bit far fetched that the air handlers would be exact fit......however, as previously stated, I am not familiar with residential A/C and maybe some size standardization exist.
Should I elect a heat pump with new air handler would there be much modification installing that system where a split system previously existed?? The tech already stated he doesn't reuse the Freon lines and always replaces them when replacing a system so that shouldn't be a concern. Would the heat pump system last as long or longer than the split system.......would it be working harder or would it be less strain with more efficiency? I guess what I'm asking, which would you choose here in Florida given the 3-4 months of 100F days? Thank you for your response as it was very informative.

ANSWER: Dennis,

Your house being built in 2007 means your unit is only 6 years old, ( parts are readily available ) if the outdoor unit is in good overall condition, buy a replacement coil ,( not the whole Air Handler ) via internet , supply house , pump the refrigerant into the outdoor unit, cut the two lines at the indoor unit, slide out old coil, slide in new coil  and replace filter drier, solder/braze ,leak test line set and new coil, if all is OK evacuate lines/coil then slowly open the two service valves at the outdoor unit. That would be your cheapest, easiest way to go. The above is if your positive the leak is at the coil.

If you decide to replace with new equiptment the new Air Handler will not be an exact fit, and you would need to have make up a short custom transition piece to connect your existing duct to the air handler.

You state the A/C unit is used 365 days a year , so a heat pump  is nothing more than a A/C unit with a  reversing valve. All it does is reverse direction of the refrigerant. Heat Pumps are reliable if installed correctly as stated above.

If you like the Rheem , stick with it if you upgrade, get several bids.

---------- FOLLOW-UP ----------

QUESTION: My unit will actually be 7 years old come March of 2007. Given the fact I'm told by several HVAC professionals here in Florida that life expectancy of an HVAC system is 10 years. Contractor grade units (which I currently have) is about 7 years and the best of systems (I'm told is Lennox) will last 10-15 with proper maintainence. I change my filter every 90 days as directed by the first tech when I bought the house. Given these facts, it just doesn't make good fiscal sense to dump $1000-$1500 (the quotes I'm getting for coil replacement)into a system that is nearing it's life expectancy in March 2014. Yes, I have taken excellent care of it with servicing and filter change however, I have already replaced the condenser fan ($500) and now the evaporator coil.
Two more questions and I'll leave you be (lol).....
Would you install a heat pump system over what I already have and if so, what is the longevity expectation on a heat pump?
What are the top of the line brands? I'm told Carrier (day&night) is much better than the Rheem Classic series I already have? Lennox came up in one discussion I had with a supplier as the best you can buy....any comments on that?? Once again, thank you very much for your prompt and knowledgeable responses! I don't always get this from some "ALL EXPERTS" providers.......but then again, what credentials declare them an expert? I've seen people with 10-20-30 years in a specific livelihood who are no more informed 20 years down the road then the day they started!! I can tell by your answers you are not one of those people!!

Answer
Dennis,

Rheem makes more than just the Classis series ,( which is the mid line , they have a value line also )their top of the line is the Prestige series, Pretty much all brands have different tier levels. If you live near the salt water ,I would say expect shorter life from your system. Heat Pumps are very reliable when installed and set up correctly. Lennox has different series also, so you would need to compare a top of the line Lennox with a top of the line Carrier, Rheem or other brands. If your looking at mid level ,same applies. Nicer the nice higher the price. Higher tier units may have a quieter condensing unit, heavier rated outdoor motor, basically more features, such as both a high and low pressure refrigerant switch ,where as a mid level model may have only the low pressure switch. ETC. ETC. They are not anymore reliable than mid levels, just has more features. All the brands you mentioned probably have a Copeland Compressor, which is a world class Company and is the standard in most systems, there are other well known compressor manufacture . Only one HVAC manufacture makes their own compressor. and it's not any of the above mentioned. Day Night is not the top of the line unit ,Carrier is UTC top of the line ,and again they have value lines, mid lines and top of the lines. Carrier, Bryant, Day Night, Heil, Payne , ArcoAire, Comfortmaker are owned by  United Technologies Corporation. Day Night was reintroduced into the marketplace fairly recently. It was always under UTC umbrella, but they took it off the market years ago. I do not know the reason why. Seen one recently, at a supply house looked like a nice unit with decent features.

I do believe they make outdoor units for salty environments, I do not know how the warranty differ for those types of units. Something you can discuss with the future Installing Contractors.I believe they have a special coating on the coil.

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40+ years diversified experience.An HVAC/Refrigeration Self Employed Contractor since 1986. NATE Certifield. Answer questions pertaining to Residential and Commercial Air Conditioning , Warm Air Heating, Heat Pump systems.Mechanical and Electrical troubleshooting of these systems.Be as detailed as possible when describing problem.Packaged unit or split systems.No appliance questions.

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Installation and Troubleshooting, Mechanical and Electrical, in following areas, Refrigeration ( Walk In and Reach In Coolers and Freezers ) Commercial Roof Top and Packaged Heating/Cooling ( Natural Gas,Propane, Electric, and Heat Pumps ) Computer Room Air Conditoning Systems,Commercial Residential Packaged and Split Systems Air Conditoning and Heat Pumps.Warm Air Oil , Natural and Propane Gas Heating systems.

Education/Credentials
Graduated from Private Technical School in 1975. An HVAC/Refrigeration Contractor . Have Unlimited Heating/Piping and Cooling Contractor License.Limited Sheetmetal Contractors License.NATE Certifield. York Certifield Master Heat Pump Technician 1986. Served 33 years combination Active Duty Air Force , Air Force Reserves and Air National Guard in the HVAC/Refrigeration Shop/Mechanical Shop. Troubleshooting/Installing HVAC/Refrigeration Equiptment Worldwide. Retiring in 2003 as a Senior NCO ,and a Mechanical Superintendent.

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