What SEER for Central Fl ??

[RedVise]

1800sqf ranch house in Central Fl.
Great room in center of house with vaulted ceiling.
Due to vaulted ceiling we have a front and rear HVAC system.
Both systems cool the great room.
Rear system installed in 2000 ,
has been leaking for 2 years with yearly freon refill in spring.

I have a quote to replace Rear system from AC company that has been doing my service work for the last 6 years.
Quote:
14 SEER
R/R old system with Goodman 2.5 straight cool split system w/ 8Kw heat strip.
Labor, materials, permit, digital t-stat
Warr = 1 year labor, 10 year all parts

So... questions

Should I be looking for a higher SEER ?
How high, I have heard that above 16 SEER is a waste of money ?
My current Rear system is a reverse cycle with that I use to heat the entire house.
(Rear has back up heat strip, rarely needed)
No heat in the front system, but as I am in Central FL the rear heats the whole house without seeming to overwork the system.
Is a reverse cycle system cheaper to use that a heat strip only system ?

When I follow up I will specify all Made in USA components and new coolant lines.

Anything I am forgetting ?

Thanks for any suggestions !

Brian

 

[LS6 Tommy]

Heat pumps are always cheaper than straight resistance heat. Unless there's a GIGANTIC cost difference, I would get the highest SEER rating. BTW, heat pumps are SEER, EER and HSPF rated and the ratings are not the same, so don't try to compare two units unless you are looking at the same ratings.

Tommy

 

[crabjoe]

Get a heat pump, not just a straight AC. Heat pumps are basically AC with a reversing valve that allows it to run in reverse.

Based on what I know, which isn't much since I'm not in the HVAC biz, anything under 16 seer is a single stage unit. Also a 14 SEER unit might be rated at 15 or even 16 SEER depending on the evap coil it's matched with and the they of blower motor.

If you know the model number of the Goodman unit, you can go to the AHRI site to see what coils and air handlers might give you the most efficiency for that unit.
https://www.ahridirectory.org/ahridirectory/pages/home.aspx

Select if it's just an AC or Heat pump to do the search.

BTW, make sure you get more quotes than just one.

 

[DC73]

Should I be looking for a higher SEER ?
How high, I have heard that above 16 SEER is a waste of money ?

An easy way to choose SEER is to get a quote for every increment. That is, get a quote for a 15 SEER, a 16 SEER, 17, 18, 19, etc. By studying the cost, you'll learn fairly quickly if there is a sweet spot. For example, if a 16 SEER is $100 more than a 15, and a 17 SEER is $100 more than the 16, but the 18 is $500 more than the 17, you've found the sweet spot and should choose a 17.

Is a reverse cycle system cheaper to use that a heat strip only system ?

Yes. A heat pump will be much more economical to run than heat strips.

DC

 

[Mowerpan]

I recently researched this as well as I am planning on replacing our single 3 Ton unit and what I found was the deciding factor is whether or not you want a two stage unit or not as the 16 seer units are nearly all two stage which can increase comfort levels while keeping the electricity bill down. Unless something changes between now and winter I as far as pricing goes I will be going with a 14 seer unit as my electricity bill even in the summer months is not expensive and any potential savings in minimal.

 

[CNGsaves]

+1 to get quotes for 15,16, 17 & 18 SEER along with 2-stage. Unless you plan on moving soon, I would not settle for plain jane 14 SEER in Florida where the unit runs all the time.

Also evaluate whether your ductwork is working to your best advantage with proper flow of both RETURN and SUPPLY vents. Are your ducts exposed to heat properly insulated ??

Is that vaulted ceiling properly insulated ??? I'd bet it needs more insulation.

 

[Fixin'Stuff]

You should go for higher SEER, as I researched, A higher SEER rating indicates a more efficient unit which in turn results in lower energy bills, especially the case in Florida as it is warmer and more humid than most other states.

You have to work the math to know for certain. If you drop an extra $1,000 to upgrade but it only saves you $50/year on your electric bill, then you're betting that the system will last long enough to pay for the extra upfront cash.

For places with insane electricity prices, such as Hawaii or California, the payback comes much quicker.

 

[zmaxmotorsports]

You have to work the math to know for certain. If you drop an extra $1,000 to upgrade but it only saves you $50/year on your electric bill, then you're betting that the system will last long enough to pay for the extra upfront cash.

For places with insane electricity prices, such as Hawaii or California, the payback comes much quicker.

 

[Fixin'Stuff]

FYI, It saves more that $50/year, we must choose energy efficient electronics to save energy.

FYI, you need to do your own research and not depend on the HVAC salesperson telling you that you're going to save a fortune and that the system will pay for itself in just "a few years!".

You can check it out here: http://www.airinnovationsllc.com/energy-savings-calculator/

I punched in 4 tons and 16 SEER for the "Old" system, then 4 tons and 17 SEER for the "New" system. For Houston, at 12 cents per Kwh, the annual "savings" came out to $50 and change. When you get into the higher SEER units, the incremental price jumps get serious. The savings? Not so much...

It reminds me of the guys that sell vinyl windows. One of them visited a friend in Colorado and told him that his fabulous new windows would save so much money on his heating bill that they would easily "pay for themselves in just two years!". The windows would have cost $11,000. His heating bill was $90/month, 6 months per year, with his OLD windows. He asked the window salesperson if those windows were going to print money, as they wouldn't pay for themselves in two years even if his heating bill went to zero. Always do your own math.

 

[dw1]

I replaced my units (Furnace and Air Cond.) 2 years ago, I went high efficiency (Goodman 18 SEER outside unit and New 96+ gas furnace) but it can only achieve that rating if paired together, AC with a high efficiency furnace. My new Goodman furnace has a variable speed DC blower, together, they can operate at 18 SEER. My heating/cooling costs seemed to have gone down. Not sure if you are replacing your air handler, ask your AC guy if you can achieve that rating with a new unit paired to your exsisting air handler set up.

 

[HoosierBuddy]

You should check with your power provider and see if they offer rebates for efficiency upgrades. If they do, they will likely specify a minimum SEER that qualifies for a rebate. Typically you can find some information on these programs through the utility's website.

Sometimes that will help you make the jump to the next level of efficiency and speed your payback.

Phil

 

[RedVise]

Thanks for the suggestions. I have a much better idea of the questions and research needed.

Brian

 

[theoldwizard1]

I know it will cost more (probably a LOT more), but you should check into a geothermal heat pump. All heat pumps/air conditioners loose efficiency as the outside temperature increases. When you get into the mid/high 90s, you are WAY DOWN !

These is where geothermal pays back because the ground water will stay fairly constant.

Several of the southern states have passed laws that all new government buildings, including school, MUST have geothermal heat pumps.

 

[pseudorealityx]

I know it will cost more (probably a LOT more), but you should check into a geothermal heat pump. All heat pumps/air conditioners loose efficiency as the outside temperature increases. When you get into the mid/high 90s, you are WAY DOWN !

These is where geothermal pays back because the ground water will stay fairly constant.

Several of the southern states have passed laws that all new government buildings, including school, MUST have geothermal heat pumps.

Woah... hang on.

1. Most units are nominally rated at 95 degrees outside air temperature. So the "WAY DOWN" bit is a bit overblown.

2. There's a lot of upfront cost on any geothermal system. Wells, pumps, piping etc. Lots of first cost, and potential maintenance issues.

3. I'm not aware of ANY southern states that require government buildings to be geothermal heat pumps. And it would be a bad idea since the feasibility depends so much on the local geological conditions. Now one thing we do see a fair bit of is the requirement for new government buildings to be LEED accredited, although that's starting to phase out now since LEED has done such a wonderful job of shooting themselves in the foot.

 

[theoldwizard1]

Woah... hang on.

1. Most units are nominally rated at 95 degrees outside air temperature. So the "WAY DOWN" bit is a bit overblown.

Okay, so I should have said "upper 90s".

2. There's a lot of upfront cost on any geothermal system. Wells, pumps, piping etc. Lots of first cost, and potential maintenance issues.

I did say it would cost a lot more !!

3. I'm not aware of ANY southern states that require government buildings to be geothermal heat pumps.

Several years ago when "Dirtiest Jobs" was still shooting, Mike Rowe joined a crew in SC (or was it NC ?) that was drilling geothermal wells for a new school. That is my source.

And it would be a bad idea since the feasibility depends so much on the local geological conditions.

I don't understand that statement. IMHO, wells are the BEST solution for geothermal heat pumps. Filled with grout, they will provide 55-60° return water (assuming the size and number of wells is appropriate for the building).

 

[pseudorealityx]

My statement was simply that not all locations are great for geo-thermal due to multiple reasons. It could be the type of sand/rock below, or an ubran location with simply no available room to lay out wells, etc... could even be the simple payback depending on utility costs.

Ie... governments don't just 'declare' that all government properties must utilize X or Y system. They may prefer one type of system over another, but that's why we have mechanical engineers to analyze and recommend systems types that fit a particular application.

 

[Fixin'Stuff]

Yep, around Austin, the ground is solid limestone. Drilling the holes for geothermal would cost somewhere around $10,000. Payback on that is about never.

 

[TangoFoxTrot]

Here's a SEER calculator from the Lennox website. I'm sure there are all sorts of factors that can't be accounted for on a simple calculator like this, but for most people, I think a simple unit makes the most financial sense.

My concern with buying something high end like a variable speed unit or one with two compressors was the cost of repair down the road would easily cost more than whatever you saved on your utility bill.

Over 10 years, they are saying the savings from a 14 Seer vs 17 Seer is $370.

http://www.lennox.com/buyers-guide/tools/energy-savings-calculator

 

[nsula_country]

OP is in FL... Heat Pump is a no-brainer. Resistive heat is the most expensive heat to produce. Heat pump BTU vs Resistive BTU is about 3:1...

14-16 SEER single stage Heat Pump will be fine for your application. Above 16 SEER many different technologies are available to further improve COMFORT. Two-stage, variable speed, multiple compressors, ect. They use less electricity, but run almost constantly to maintain a closer temperature to the setpoint and better interior humidity control.

My opinions are a result of:

I do HVAC installation troubleshooting, and maintenance... When I want to... Not my primary occupation.

I am an engineer for Copeland and we built the scroll compressors in these systems. From legacy R22 to high end two-stage compressors.

Brand is not as important as installation quality. (Almost all will have a Copeland Scroll) A competent HVAC company will evaluate your duct work and run a Manual J to ensure correct sizing.

Get 2 or 3 quotes from different contractors for the same SEER, brand unimportant. You will be surprised at the spread!

CT

 

[shawhite]

My concern with buying something high end like a variable speed unit or one with two compressors was the cost of repair down the road would easily cost more than whatever you saved on your utility bill.

Took the words right out of my mouth. Look at the repair cost for the multi speed blower motors or the 2 stage compressors. They are easily 3 times what the single speed blower motor or single stage compressor cost just to say $50-$100 a year in electric cost.

 

[danski0224]

You will not get your claimed SEER rating if your ductwork cannot flow enough air.

Have your contractor perform a TESP (total external static pressure) test of your existing system. I'd be willing to bet that it is over 0.5" w.c., and if it is, then you have ductwork issues.

If your contractor does not know what TESP is or how to measure it....

 

[nsula_country]

+1

New systems are designed for up to 0.7" wc st pressure. Older home duct design, mobile homes, and poor duct work can be over 1.0" wc st pressure.

Louisiana mandates pressure test and leakage testing on all new installs. Mandated to meet SEER rating.

CT

 

[RedVise]

Again, Thanks for the help, being in Florida, I need to get this right !

Have your contractor perform a TESP (total external static pressure) test of your existing system. I'd be willing to bet that it is over 0.5" w.c., and if it is, then you have ductwork issues.

Will do.

Look at the repair cost for the multi speed blower motors or the 2 stage compressors. They are easily 3 times what the single speed blower motor or single stage compressor cost just to say $50-$100 a year in electric cost.

14-16 SEER single stage Heat Pump will be fine for your application. Above 16 SEER many different technologies are available to further improve COMFORT. Two-stage, variable speed, multiple compressors, ect. They use less electricity, but run almost constantly to maintain a closer temperature to the setpoint and better interior humidity control.



A competent HVAC company will evaluate your duct work and run a Manual J to ensure correct sizing.
CT

Looks like 14-16 SEER single stage Heat Pump is what we will price.

Would I be asking to see the results of the Manual J, or would it be incomprehensible to me ?

Brian

 

[nsula_country]

Seeing the results of the Manual J would prove the installing contractor actually crunched the numbers! The other option is stand at the curb, hold out your hand and see how many fingers it takes to cover the house... How many fingers = tonnage! (HVAC joke).

Good luck

CT