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CantRepeat
04-29-2009, 08:37 PM
I have some general questions about split systems if anyone wants to entertain them.

ogrover3
04-29-2009, 08:45 PM
will try to answer have a company in central florida

CantRepeat
04-29-2009, 09:03 PM
will try to answer have a company in central florida


Thanks!

SEER Rating: I was wondering how much difference in a 13 to 15 seer. Is there really that much difference from a 13 to 50? If I have a $200 bill with a 13 what should I expect from a 15?

Single stage, two stage and variable speed air handler motors? What is the effect of these?

Does an air handler really change the rating of the outside heat pump?

R22 vs 410A is just an enviro issue or is the 410A better?

damaged442
04-29-2009, 09:45 PM
I don't think that R22 over R410A is strictly an environmental issue, although the R410A doesn't form the chlorine radical ion which reacts with ozone. It's a fact that R22 is going to be phased out. Some say by 2010, some say later, but it's going. With that the case, you can expect the prices to shoot up if it goes the way of R12. The R22 systems run with mineral oil, where the R410A systems run with synthetics. You can get into arguments about dino oil vs synthetic all day...so I won't go there. I have read that R410A systems tend to run cooler than R22 systems and as a result they feel would be less prone to failure due to overheating. Only time will tell I guess. If it were me, and I was buying a new system, I wouldn't go with R22.

ogrover3
04-29-2009, 10:22 PM
seer rating. right now some 15 seer systems and over qualify for a tax rebate thanks to mr. obama up to $1500.i would guess maybe 10 to 20 dollars less on the bill really depends on the system in place now. with the tax rebate the 15 seer is nearly the same price as the 13 seer. if not it makes the difference alot easier to make up in savings on your electric bill.
i think much over 16 is overkill but just my opinion

variable speed i am not a real big fan of because the motors if the go out are pricey also they have several circuit boards built in and can also go out easily because the unit contains moisture in it which is not friendly to these boards. but if not for this i think they are very good. quiet and comfortable.

the air handler does go into account when calculating seer. for instance the variable speed motor.

finally as far as 22 vs 410.
i think 22 will be around and there will be drop in replacements, could get pricey down the road?
at first i wasnt a fan of 410 it was very pricey but has now come to be reasonable against the 22. the thing i dont like is the high pressure that 410 runs at. 22 evap coils run at 250 psi and had leaks 410 runs at pressures of 400 or greater so whats going to happen with that.

hope this might help a little it is all my opinion with a little knowledge added in. any more questions feel free

ogrover3
04-29-2009, 10:24 PM
i would definatly go with heat pump if that is what was meant by single stage and two stage

rholmes
04-30-2009, 01:23 AM
Thanks!

SEER Rating: I was wondering how much difference in a 13 to 15 seer. Is there really that much difference from a 13 to 50? If I have a $200 bill with a 13 what should I expect from a 15?

Single stage, two stage and variable speed air handler motors? What is the effect of these?

Does an air handler really change the rating of the outside heat pump?

R22 vs 410A is just an enviro issue or is the 410A better?

I actually sell them to the wholesalers in the market, let me take stab at it for you.

The seer rating is actually fairly easy to get an estimate of what it will help save you on your utility bill, you take the lower SEER number and divide it by the higher one to get the estimated saving. 13 divided by 15 is .86666, so you can expect a 15 seer to cost about 86% of what a 13 seer does, or a bill to be about 14% cheaper.

Staged blowers and variable speed motors are designed to increase the efficiency of the system. If it were me, go for the variable speed. They convert AC to DC, and are much more efficient. They are partly what raise the SEER level of equipment, because they use a vast amount less electricity (I also sell GE/Marathon motors, and have done some pretty cool tests and read the data). They are actually a stronger motor and 95% of those replaced in the field as "defective" are actually installer error. A regular AC motor has generally has between 2-4 speeds. When installed, the installer picks which speed is needed based upon airflow, cooling needs, a whole slew of things. The important thing to remember is that they don't vary, it is a constant. With the variable speed, you get two types, constant torque or variable cfm. They achieve the same effect, and ramp up or down depending on needs, just like the engine of the car. Lots of throttle to get going, not so much once up cruising. Layman terms, but you get the point.

Airhandler changing the heat pump, not quite sure what you are asking here. When creating a system, you should always change the airhandler and condenser IF you are changing the seer rating. You don't want to put a 13seer outside and leave the old 10 seer blower inside. Massive problems occur, more technical than you want to deal with, ultimately costing you mucho dinero in utility bills, maintenance of equipment, etc. I can provide a Power point on it if interested. And having a variable speed blower on the airhandler alone can raise the SEER rating of the entire system by 1 point (from 12 to 13 for example).

Actually, R22 is a better refrigerant when it comes to cooling capacity. Current EPA requirments will mandate that by 2010, only 20% of the amount of R22 refrigerant will be produced as was being made back in 1992 during the Montreal Protocol. Almost all manufacturers of condensers stopped production or will have by July of R22 units. It is because R22 is a HCFC, where as 410A is HFC. Most people will tell you HCFC's are responsible for global warming, ozone depletion, etc. SO the switch has been to 410a. R22 will continue to climb in price, we have seen it go from around $75 a year ago for a drum up to about $190 NOW. There will always be drop ins that are replacements or can be used to make the system work, however, these drop ins are still a little unproven. Reason being, drop ins refrigerants are actually blends of various types of refrigerants out there that have different FLOC points and the refrigerants in the blend have different properties, exposure to moisture in the filter driers, saturation points and refrigerant loss will actually change the composition of the refrigerant. Imagine a blend that is 25/25/50. If one of the componets has a higher natural pressure and we have a miniscule leak in the system, you might lose 5% of just one of the parts that makes the blend, however we create a entirely new addition to the system that won't act the same as before.

Long story short, stick with the 410a. It will be around longer, stay cheaper, and still be available 15 years down the road when it comes time to replace the system anyways.

Class starts @ 8am sharp. ;) Hope you took notes!

CantRepeat
04-30-2009, 07:07 AM
Thanks everyone, very informative to say the least!

System A: a 2.5 ton system that has a 13 seer outside heat pump with a 15 seer 2 speed air handler that brings the system up to 15 and qualifies for the tax credit.

Or

System B: 2.5 ton outside heat pump that is a true 15 seer and variable speed air handler that is 15 seer when combined make a 15.5 that qualifies for the tax credit.

Both are R410a. The first system is $3800 install and the second is $4600 installed. I figure a tax credit of $1380 on the second system takes the cost out of the question. I figure on a $300 a month bill that I could save somewhere between $24 and $42 bucks depending on the month. My bill runs between $200 and $300.

The system I have now is a 10 SEER and has been in the house new since we bought. That was over 12 years ago. If i save on average $30 bucks a month on the bill the system will pay for itself in about 9 years.

So, HVAC guys, would you recommend system A or B and why?

Craig
04-30-2009, 10:03 AM
There will always be drop ins that are replacements or can be used to make the system work, however, these drop ins are still a little unproven. Reason being, drop ins refrigerants are actually blends of various types of refrigerants out there that have different FLOC points and the refrigerants in the blend have different properties, exposure to moisture in the filter driers, saturation points and refrigerant loss will actually change the composition of the refrigerant. Imagine a blend that is 25/25/50. If one of the componets has a higher natural pressure and we have a miniscule leak in the system, you might lose 5% of just one of the parts that makes the blend, however we create a entirely new addition to the system that won't act the same as before.

Long story short, stick with the 410a. It will be around longer, stay cheaper, and still be available 15 years down the road when it comes time to replace the system anyways.

Class starts @ 8am sharp. ;) Hope you took notes!

410a is a mixture of 134a and another that I cannot think of at the moment, it is pretty close to 50/50.

410a is the way of the future for now so I would get one of those systems.

I am a research engineer in HVAC; I would go with the most efficienct, or B.

Getting the more efficient heat pump seems wise but a variable speed air handler is much more complicated so maybe it is just a problem waiting to happen. Some of the other guys who have chimed in can probably answer that better than I.

CantRepeat
04-30-2009, 12:44 PM
410a is a mixture of 134a and another that I cannot think of at the moment, it is pretty close to 50/50.

410a is the way of the future for now so I would get one of those systems.

I am a research engineer in HVAC; I would go with the most efficienct, or B.

Getting the more efficient heat pump seems wise but a variable speed air handler is much more complicated so maybe it is just a problem waiting to happen. Some of the other guys who have chimed in can probably answer that better than I.


Thanks Craig.

I'm under the impression that the biggest monthly savings come from the variable speed motor handler. When talking to my installer, he led me to believe that they have about the same failure rate it's just that the motor was about $20 more then the two speed model motor.

On a side note: I don't think I've come across a profession that gets more upset when you ask technical questions about their choices like the installers I've spoken to. It seems that most of them are very happy when a customer says I have 2000sq ft house what do I need. I just can't do business like that. I've come out on the short end of the stick to many times.

Thank you everyone for your input and suggestions.

TX.X-30 fan
04-30-2009, 01:06 PM
What is Puron its in the house we bought last year, I hate heat pumps now that I have one, they even suck in mild climates. No heat and the run constantly to keep it 68.

CantRepeat
04-30-2009, 02:21 PM
Strange, we normally keep the thermostat set between 68 and 72 and don't have that issue with our 13 year old 10 SEER right now. The summer runs a pretty even 88+ from the end of May until the end of Aug. I'm banking on the fact that it will be even better with the new 15.5 SEER system.

If this new system last as long as the old one, it will have paid for itself in less then 9 years. We are going to setup a little kitty and put all the savings in pot. When the new system goes out the next one will be prepaid!!

Jesus_Freak
04-30-2009, 03:41 PM
...If this new system last as long as the old one, it will have paid for itself in less then 9 years....

This brings up something that many would consider important...payback period, ROI, ROR, etc. I am often curious about how long it really takes to recoup the capital on new HVAC units. Did you figure the time value of money in your estimate above? Something else that may influence the math is that you might tend to move your setpoints a little (down in the summer, up in the winter) once you get the new power unit. I am sure someone here has looked at this....please share.

CantRepeat
04-30-2009, 04:31 PM
This brings up something that many would consider important...payback period, ROI, ROR, etc. I am often curious about how long it really takes to recoup the capital on new HVAC units. Did you figure the time value of money in your estimate above? Something else that may influence the math is that you might tend to move your setpoints a little (down in the summer, up in the winter) once you get the new power unit. I am sure someone here has looked at this....please share.

That's the strange part too, the South. We only have about 30 days in the year that we can go without either heating or cooling the house. The bill never really changes from one season to the next. We do however, like you suggest, change the setting at some point to make it either cooler or warmer in the house depending on the time of year. I'll have to watch how much that changes from summer to winter.

Craig
04-30-2009, 04:44 PM
Another thing that could really help your costs is a better control system. One may come with the new unit, I am not sure, but a good thermostat and a programmable controller will go a long way.

One with the ability to program daytime/nighttime settings would help a lot if you do not have it already.

Jesus_Freak
04-30-2009, 04:58 PM
...One with the ability to program daytime/nighttime settings would help a lot if you do not have it already.

I have one of these and use it constantly, but the helps "a lot" will depend on the user's comfort level and the climate. A house has significant thermal intertia. Moving that around has its price. I use mine, but I never know if it is worth the effort.

CantRepeat
04-30-2009, 05:10 PM
Another thing that could really help your costs is a better control system. One may come with the new unit, I am not sure, but a good thermostat and a programmable controller will go a long way.

One with the ability to program daytime/nighttime settings would help a lot if you do not have it already.

I got the Honeywell VisionPro 8000. It's fully programmable and was one of the items I would not bend on. If I can raise the thermostat a few degrees during the day and have it cool back down before we get home I see that as a plus. The other thing is around here at night it tends to cool off a bunch around 2 or 3 am. Having the thermostat adjust so it doesn't turn the unit on until say 7 am will be nice as well.

rholmes
04-30-2009, 05:23 PM
What is Puron its in the house we bought last year, I hate heat pumps now that I have one, they even suck in mild climates. No heat and the run constantly to keep it 68.

Puron is trademark name for a "brand" of refrigerant used in Carrier systems, basically it's just 410A. Most HVAC techs will tell you that a HP or AC is capable of providing around a 20 degree difference between the interior and exterior temperatures.

We keep our home around 78 in the summer and 66-68 in the winter. Programmable thermostats do provide a fairly significant savings. The Honeywell 8000's maristar has are essentially top of the line, allowing you to have 4 temperature "times". You can easily expect a programmable thermostat to give you a minimum 10%-15% in efficiency.

I have a dual zone in my house that uses the same unit, but a system of dampers, etc to control the airflow to the zones. At night in the summer, I'll let the downstairs get up to 80, but keep the upstairs at 76. Similarly during winter, I'll let the downstairs get around 62-64, but keep the upstairs around 68. It does make a big difference, I went for a while with plain thermostats before I got hooked up with my programmables, there was a definite difference in the utility bills.

etduc
04-30-2009, 08:27 PM
What is Puron its in the house we bought last year, I hate heat pumps now that I have one, they even suck in mild climates. No heat and the run constantly to keep it 68.

I believe you are not happy, and I am not directing this comment at you.

It has been my experience, when people who don't like their comfort systems. Bought a system that was not design to their needs, the system is broken, or the system was installed incorrectly. (This includes building construction or changes.)

There can be a number of reasons, for a mech system not working properly. (Sometimes, it is not the hvac guys fault.)

Some on this board, who are knowledgeable... some others, not so much.

And yes, I am in the business.


I'll be happy to test your house and system, or provide info. Pm me, if I can be any help.

ogrover3
04-30-2009, 08:36 PM
92Maristar

if it were me 15 seer is 15 seer and once again the variable speed is a very nice feature but costly repairs and maybe not available on fri night in aug when it is 100 deg outside

rholmes

i would be interested in the powerpoint that you should not change just one part of a system
done all the time here no problems
thanks

CantRepeat
04-30-2009, 09:17 PM
92Maristar

if it were me 15 seer is 15 seer and once again the variable speed is a very nice feature but costly repairs and maybe not available on fri night in aug when it is 100 deg outside

rholmes

i would be interested in the powerpoint that you should not change just one part of a system
done all the time here no problems
thanks

I'm wondering if what is meant by not changing one part of a system is the upgrade part. For sure if an air handler goes out changing it and not the heat pump as a repair is done all the time. Miss matching split units seems to be not recommended by many people.

rholmes
05-01-2009, 12:34 AM
92Maristar

if it were me 15 seer is 15 seer and once again the variable speed is a very nice feature but costly repairs and maybe not available on fri night in aug when it is 100 deg outside

rholmes

i would be interested in the powerpoint that you should not change just one part of a system
done all the time here no problems
thanks

Shoot me your email. Be glad to send it.