What size is the current AC and what is the size of your house? I am skeptical you need a 5 ton AC. If the AC is over sized you will have poor humidity control. Installing a 4 ton will get the price down.

I also question installing a 10 KW heat strip. It seems too big. Does the temperature ever go below freezing? I would spend the extra money on upgrading to a heat pump and installing a small heat strip (5KW) would seem to make more sense. For some reason AC only with heat strips is the way it is done in Florida.

7.5 KW heat strip=25,000 BTUs of heat...

Thanks for the replies. Shows you how much I know..I thought it was a heat pump.
Our house is 2500 sq ft with vaulted ceilings and a couple walls of sliders. The current AC is 4ton. It does occasionally go below freezing, we typically use our heat a couple times a year. Our bedroom is at the end of the run and we like to have that room really cool for sleeping.

Given your climate, if it were me I would check out the Bosch Inverter.

The approach this machine takes is unique. It's a heat pump, it's an AC all in one. But it's more than that.

The Bosch Inverter will cost more up front.

But it will pay for itself in the long run. I live in an all Electric home here in Katy, Texas very similar climate to Florida. Just installed one of these at my house here in Katy. After installation electric bill cut in half. This month's bill is the lowest bill in 3 yrs at my house since I moved here at $56 @ 11.6 cents per kwh. I was paying around 9 cents a kwh when I moved here. (I don't use heating except to remove chill from the house on cold days)

Put one of these Bosch babies in for a long time customer several months earlier with AC only set up because they have gas heat and it cut their electric bill in half.

Here's a recent Bosch Heat pump thread that goes into more detail.

You should not increase the the size from 4 ton to 5 ton even thought the company hour husband likes "strongly suggests" the bigger size. Your duct work is not sized to handle 5 tons of air flow, therefore you will not get the benefit of a larger system. In addition the climate in Florida tends to be humid. The 5 ton system will short cycle which will cause the humidity to be higher. The installer will say it is a 2-stage system so it will have good humidity control. That is true to some degree, but why buy a system that rarely ever goes into the second stage?

The cost difference between an AC only and heat pump is usually a few hundred dollars. I suggest getting quotes on the 4 ton sizes for both. The Bosch is a very nice system, but in general you should stick with the brands that are most common in your area. The inverter type is going to be significantly more money. You have to decide if it fits your budget.

The normal response to an upsizing suggestion is to ask for a calculation of heating and cooling demands, but as has been seen repeatedly on threads here, with a little number fiddling, anything can be justified.

Let’s ask the most simple question, did the previous 4 ton unit heat and cool to your satisfaction? If there was some dissatisfaction with how the previous unit functioned, what was the complaint? As long as the previous unit cooled enough on the peak heating day of the year, there is absolutely no need for a larger unit. In fact, as noted above, the larger unit would likely make the home less comfortable. Be wary of an installer that suggests that a larger unit is better because it will run less, or some such crap. A properly sized unit will run almost all the time at the hottest point of the year, and some unscrupulous types will use that to suggest upsizing is needed.

The Bosch is a very nice system, but in general you should stick with the brands that are most common in your area. The inverter type is going to be significantly more money. You have to decide if it fits your budget.

Budget: you pay $200 a month in utilities or more. (What you pay to utility company for electric power)

If you live in some place like New Jersey like Mike your electric bill doesn't stay elevated, because New Jersey climate is cooler.

So what is the payback for cutting your utility bill in half if you average $200 a month or more now?

You live there 8 months --- so if you bill is 200 dropped to $100 = $100 a month.

8 months x 100 = $800 annually.

x 10 = $8,000 So ultimately it depends on what you are paying in utility costs. Those utility costs are directly tied to how much or how little you use your AC system now.

If you are paying less than $200 a month in electric costs, then it may not be worth it to go to the Bosch system. Florida is a warmer climate where cooling is likely needed all year long. Which is why I suggested it to you.

It's December 16, 2019 yesterday in Katy, Texas it was 80 degrees. I've been running my Bosch in cooling mode.

Are there risks in selecting the Bosch, sure... BUT you could do far worse with a regular brand. If the system pays for itself what difference does it make?

Another interesting feature of the Bosch is that they don't make a 4 ton unit. You buy a 5 ton unit and during installation it is configured as either 4 ton or 5 ton. So you remove the argument over sizing of the system, if you're not sure.

If the Bosch system is configured as a 4 ton and it's determined that it can't handle the load it can be reconfigured to a 5 ton. There is no other brand that I know of that has this option.

CoolAir, is your professional recommendation the original poster should abandon the ducts in their 2500 sq. foot house and install ductless heat pumps in each bedroom and throughout the rest of the house?

The current system has done ok on most days, just a few where it didn’t get the house as cool as I want. It takes a long time to get it cool though. My one complaint is that I would really like to get the bedroom VERY cool at night. This can’t be accomplished without cooling the entire house and turning the temperature down a lot earlier than what is ideal. The way I understand it the best way to accomplish this would be to put a mini split in the mbr? We got a very high quote for that by one of the companies. I think he told my husband the biggest cost would be getting the electric all the way to that side of the house. Is there another way to get that bedroom on a “different zone”?
I called yesterday about getting a price for a heat pump and they both said that heat pumps are not really cost effective this far south in Florida because we have so few days with cold temperatures (none so far this season). We are about 2 1/2 hours south of Tampa.
The space the air handler is current in is very tight. The only option to keep it in its current location is by going with the shorty Rheem. There is one duct that makes a sharp turn right away and one person said this is not ideal. We got a quote to move it about 12 ft to above the garage for $1200. Does this make sense?
They each are saying that our house rates out at about 4.5ton. I guess the zone, vaulted ceilings and glass contribute to this.
What would you do if you were us? Thanks again for your help, we really appreciate it.

Twosit4me,

If you're wanting a zoned set up the mini split option is likely your better way because you have 'no room' at the air handler. (from what you've said)

Dealing with zoning is complicated and needs room to be able to do it elegantly, not a hack job operation. This is why zoning is not a fix for everything. Certain homes are just not 'cut out for it'.

The Bosch Heat pump is what I was recommending....... not because it's a heat pump. But because of what it does in AC mode. Bosch doesn't make an AC only system. You either buy the heat pump or take a hike. Which means 'it's not for everyone'. Like areas of the country that are less humid and electric costs are lower.

Because of the over sizing issue, the humidity your area has to deal with make it a good choice. However, if you choose Bosch, you get the heat pump as a bonus because they DO NOT make an AC only option. Look for a Bosch Dealer in your area. (do not compare the Bosch to a single speed or even a two speed AC --- it is not a fair comparison based on what the Bosch does for you.)

Compare the Bosch to other manufactures Inverter solutions. For any manufacturer this is the MOST HIGH Model. The highest model they have typically in the 20 SEER range of efficiency.

The Bosch has the ability to ramp up and ramp down as the load dictates. Because of this operation it removes humidity much better which in turn makes you feel more comfortable.

In other words you could oversize the Bosch Inverter and it is only going to deliver the amount of cooling needed. If the Bosch is over sized it more or less is unused capacity. It starts slow and ramps up... how high or low it ramps is dependent upon refrigerant pressures that directly correlate to air temperature.

Because as air temperature changes --- so does refrigerant pressures. (indoor and outdoor temps)

If you choose the mini split option you're choosing to ignore the issues with the main system and or possibly spend more than just fixing the issue(s) you have. It is my opinion if you go that route, you'll probably regret it later on down the road.

Things like: some ugly box hanging on the wall, another appliance to maintain and fix when it breaks as well as replace when that time comes... etc.