real-world difference in 13, 14, 15, etc. SEER

[collbill57]

I am looking for a new split heat pump - and the questions coming up from the contractors are 13 SEER or higher? 410A or 22?

So, given the many options out there, what are the actual performance comparisons between the higher SEER units (16+), 14-15 and good old 13?

Of course, the tax savings will come into it, and if the cap-n-trade bill passes the house, I bet the 13 won't be good enough to allow you to sell your house...

Thanks.

[beachtech]

410a hands down! anyone selling 22 systems is as foolish as person buying!

is gonna take 14 SEER or better in most lines of equipment to make tax credit. buy as much efficiency as you can afford and payback is within reasonable amount of time, comfort also comes with higher efficiency and two stage cooling equipment.

most home buyers aren't going to say we don't want this house, it only has 13 SEER. most home buyers aren't savy as too look at the HVAC other than to pay a home inspector that doesn't dig deep enough into the equipment to give actual performance and condition

[gary_g]

I am looking for a new split heat pump - and the questions coming up from the contractors are 13 SEER or higher? 410A or 22?

So, given the many options out there, what are the actual performance comparisons between the higher SEER units (16+), 14-15 and good old 13?

Of course, the tax savings will come into it, and if the cap-n-trade bill passes the house, I bet the 13 won't be good enough to allow you to sell your house...

Thanks.

For a heat pump to qualify for the Fed Tax Credit: 15 SEER and 12.5 EER and 8.5 HSPF. All 3 must be met.

With that said, a 13 SEER heat pump will have a lower HSPF - Heating Seasonal Performance Factor (some as low as 7.5). The condenser (outdoor unit) will probably be louder than a higher SEER condenser.

In my opinion (and I've been beat up many times on this site for it), a 14 or 15 SEER usually offers the best combination of purchase price and operating costs.

Depending on your geographical area, a 2-stage compressor (usually 16 SEER or higher) can help with summer humidity removal.

Good luck.

[ClassicDave]

Definitely look into a system that at least qualifies for a tax credit.
Most important, the systems that qualify get you out of a RNC (residential new construction) models. Many A/C guys love selling the low models because they think that's all people can afford. They don't realize that people want to save money over the life of the air conditioning system.

[collbill57]

That is kinda where I think I'm heading. I'd like to have the performance for tax purposes, and as you say, it will continue to pay back in savings over the life of the unit. Electricity won't be getting cheaper.

This is a builder-original system (1999) and lots of them have been replaced in this neighborhood. Neighbors have said it really helped their electric bills.

I want a scroll compressor and variable speed fan. 2-stage compressor would be a nice addition.

We're in the Atlanta area so it is quite warm, along with humidity. We cool here a lot more than heat, but low temps get to the teens for a couple - 3 weeks.

Now I gotta start looking at 3T models that meet these specs.

Thanks!

[bluefitness]

Definitely look into a system that at least qualifies for a tax credit.
Most important, the systems that qualify get you out of a RNC (residential new construction) models. Many A/C guys love selling the low models because they think that's all people can afford. They don't realize that people want to save money over the life of the air conditioning system.

In most cases, your initial cash outlay negates in cost savings you experience over the life of the air conditioning system. Therefore, you are not actually saving money over the life of the system. Even in Florida, it takes way too long to recoup your initial investment. It even takes longer if you take opportunity costs into account (one could invest the money into an investment that will bring in a positive return).

[collbill57]

Aaah - the crux of the biscuit:

Say I select a 3T 14SEER unit, and then compare the operating costs to a 15 or 16, at higher initial cost, in my (Atlanta) environment, how much difference will I see? (Ballpark, of course). The efficiencies go up and the incremental operating cost savings go down. But at what rate. My parents just put in am 18SEER unit. I'm interested to see their electric bill compared with the previous month and same month(s) a year ago. Will post them when I do.

Seems to me the reduction is asymptotic, getting smaller and smaller, but at a slower rate.

Going from an old 10 SEER or lower (my 1998 system) to 14 will be a nice drop in operating cost, I presume.

As I said earlier, if initial $ weren't an issue, then I'd go geothermal. Or if I had a spring on the property... ;-). My brother built a home and drilled a water well for his geo unit. Don't think he's recycling the water though.

[gary_g]

www.hvacopcost.com gives a ballpark estimate on operating costs using different SEER systems. Not sure how they derive their numbers, that's why I call it a ballpark figure.

A 10 SEER to 14 SEER should be a 30% to 40% reduction in energy consumption. That's the range I saw when I replaced a 21 year-old heat pump.

[ChuckHVAC]

If geothermal is not an option, considering only actual monthly cost, we usually end up installing 14 of 15 SEER. But with the tax credit figured in, right now 16 SEER is usually a good option. Based on economics alone we never install over 16 SEER.
Real world performance is going to depend on proper installation and maintenance more than the SEER numbers or the HSPF. Get a good relationship with a quality contractor and discuss the best options for your situation. In our climate I am more concerned with heating performance than cooling performance.
In my experience the rated cooling performance of a heat pump is fairly accurate if properly sized and installed. The heating performance of air source heat pumps is always overrated because of the defrost cycle. Theoretically heat pumps with demand defrost should out perform basic timed defrost heat pumps of the same HSPF rating.

[collbill57]

Thanks Gary,
Those are the numbers I was expecting to see. As with all things environmental, it is an estimate between the lab and the actual conditions, but 30 to 40% is a number I can love. Especially when I get the water heater turned off.

Chuck,
Our heating season is not nearly as long as yours. I have thought for years that bigger coil area in the condenser - turned into the evaporator during heating mode - would lead to higher heating performance. Then the costs of material, refrigerant, pumping energy, etc. and crunch all those lines and then the bean counters tell you where to put it! Big business. ( I know the fight on ROI for capital systems and products).

Maintenance and install are key - I agree. When chasing those small numbers it really matters. My Dad says that he notices their 18SEER system kick on in response to cooking or shower - it is only the 2 of them - in response to humidity increase. They are in East TN where it is like a sponge in the summer.

Thanks a lot,
Bill

[udarrell]

I don't know what the Fed weatherization money & credits will amount to, but we should always start with what we can do, that's cost-effective, with the building.

Correcting excessive Air infiltration rates & ductwork system problems will produce many fold more energy savings than the difference in SEER numbers. I'd incorporate both in my HVAC business.

If you can drop heat-gain by a ton, a smaller more efficient unit will provide excellent comfort with a much lower utility bill, plus big heating savings.

It's okay to go to the higher SEER units, but the govt should not outlaw anything below a 16-SEER like they did with the 10 & 12-Seer units.

You can take a high percentage of homes & upgrade the weatherization factors & the ductwork, install a smaller tonnage unit & get great energy savings.

Paul42, is an exceptional example of 2-Ton cooling tremendous square footage. Check his posts, click on his stats!
http://hvac-talk.com/vbb/member.php?u=3467 - Darrell

[hotntired]

There are quite a few options to get you into the qualifying tax credit systems, most are using two stage compressors. However, there are several brands that will get you there more economically by using a 14 SEER condenser and an air handler with an ECM motor (not variable speed). Check into these options with YORK in the YHJF series heat pumps and Several lines from ICP (Comfortmaker, Tempstar, etc.). I have found these to be in that "sweet spot" for consumers: getting the tax credit for efficiency and not breaking the bank on the initial installation.

[bluefitness]

Thanks Gary,
Those are the numbers I was expecting to see. As with all things environmental, it is an estimate between the lab and the actual conditions, but 30 to 40% is a number I can love. Especially when I get the water heater turned off.

Chuck,
Our heating season is not nearly as long as yours. I have thought for years that bigger coil area in the condenser - turned into the evaporator during heating mode - would lead to higher heating performance. Then the costs of material, refrigerant, pumping energy, etc. and crunch all those lines and then the bean counters tell you where to put it! Big business. ( I know the fight on ROI for capital systems and products).

Maintenance and install are key - I agree. When chasing those small numbers it really matters. My Dad says that he notices their 18SEER system kick on in response to cooking or shower - it is only the 2 of them - in response to humidity increase. They are in East TN where it is like a sponge in the summer.

Thanks a lot,
Bill

Please keep in mind the energy savings are for heating/cooling consumption only. A lot of sales people misguide customers into believing they will save that much on their total utility bill. It is also important to see the actual SEER rating with the complete system. Different air handler matches produce different SEER ratings. Also, you should take into account existing problems like Darrell suggested.

[motoguy128]

Ya... but since when is the governemnt any good and putting resources where they can have the greatest impact. It always goes at the most abvious solution rather than the root cause because the "sheeple" as someone on here called them, can't see past the most obvious.

"Gas prices are too high and my car uses too much gas". Buy a smaller vehicle! When I was little, our family of 5 took trips in a midsized sedan with a roof top carrier. It can be done.

My home costs too much to heat. Build/buy a smaller home. I bet 25% of Americans don't even think it's possible to have a 3 bedroom home with 1-1/2 baths that's only 1100 sqft. I live in one. It's very space efficient. With modern building practices, I could easily cool it with as little as 1-1/2 tons with capacity to spare and even heat the a full basement too with a 40k BTU furnace.

We spent the last 2 decades supersizing everything. Lets get back building quality instead of quantity when possible.

[jerryd_2008]

... considering only actual monthly cost, we usually end up installing 14 of 15 SEER. But with the tax credit figured in, right now 16 SEER is usually a good option. ...

Talking cost, you should also factor in the rebates offered by the manufacturer. May require some extras, some you might want anyway, but the rebates can be dare I say much higher for top end SEER/EER/HSPF. I figure the total tax credit/rebate discount on a very competitive high-end system price will be around 34%.

Then there is the comfort view. I finely figured out that I bought a top end HP system in large part for comfort with an assumption of more efficiency. Hope I am not wrong.

...
My home costs too much to heat. Build/buy a smaller home. I bet 25% of Americans don't even think it's possible to have a 3 bedroom home with 1-1/2 baths that's only 1100 sqft. I live in one. It's very space efficient. With modern building practices, I could easily cool it with as little as 1-1/2 tons with capacity to spare and even heat the a full basement too with a 40k BTU furnace.
...

Maybe, Motoguy. I listen weekly to a call-in energy expert's radio show (syndicated across a number of states) here in Arkansas. I am shocked when people answer his standard question (he is an architect also) how big id the house followed by and what is your recent monthly electric bill. The bill is frequently quite high in the sub-2000 sqft range.

Motoguy, our house is at least 3 times larger than yours (sorry, loved the view and knew we didn't need that big) and built in 1994. We keep the heat at 70 in the winter, AC at 78 June-September, and just enjoy open doors in the extremely long Spring and Falls here. Total NG and electric is $15-1600/year and we always have the PC on or 2 TV's with security lights (CFL or little night lights where we can). Yea, don't build bigger than needed but isn't it really about how you build? Also wouldn't want to raise 3 kids in an 1100 sqft house (is that with basement?) if I didn't have to.

An interesting fact. We went to an open house very recently for an all-electric, 2900 sqft house. The above eferenced energy expert was there because they met or even exceeded his construction criteria. HVAC cost per month is $40.

[eloy]

I like high seer equipment, not only for their ability to better dehumidify the air in you home and multi staging options but also for their better warranty. Try to get extended labor warranty program from manufaturer. They really come handy when the equipment fails and an expensive repair is needed. The 13 SEER line also is a lower quality built than main line products (usually 14 seer and above). Make sure that the system is a true certified match. You could ask to the contractor for the ARI cetificate or get the model # of the equipment and check it out at http://www.ahridirectory.org/ahridir...ages/home.aspx
Good Luck!

[motoguy128]

Maybe, Motoguy. I listen weekly to a call-in energy expert's radio show (syndicated across a number of states) here in Arkansas. I am shocked when people answer his standard question (he is an architect also) how big id the house followed by and what is your recent monthly electric bill. The bill is frequently quite high in the sub-2000 sqft range.

Motoguy, our house is at least 3 times larger than yours (sorry, loved the view and knew we didn't need that big) and built in 1994. We keep the heat at 70 in the winter, AC at 78 June-September, and just enjoy open doors in the extremely long Spring and Falls here. Total NG and electric is $15-1600/year and we always have the PC on or 2 TV's with security lights (CFL or little night lights where we can). Yea, don't build bigger than needed but isn't it really about how you build? Also wouldn't want to raise 3 kids in an 1100 sqft house (is that with basement?) if I didn't have to.

An interesting fact. We went to an open house very recently for an all-electric, 2900 sqft house. The above eferenced energy expert was there because they met or even exceeded his construction criteria. HVAC cost per month is $40.

You'd probably fidn that all of thsoe smaller homes were either constructed before 1980, or were constructed cheaply. Sort of similar ot why compact cars in hte US are always cheap. It's assumed that nobady would pay $30k or a compact car that had descent suspension and had real leather seats and other luxury features. They sell plenty in Europe where gas is cheap. MFG's are afraid to sell them here. It brings bad images of failures like the Cadillac Cimmeron (sp?). I'm sure GM wishes they could take that one back.

the point being that a 1500 sqft home built with the same techniques as the 2900 sqft home you mention would have a electric bill around $28-30.

Small homes do suffer from having a less favorable surface area to volume ratio, especially when you compare a 2 stroy home vs a smaller single story home. Cut off the top floor of a 2500 sqft homes and you heating and cooling bills may only drop by 30% or less because the exterior roof and floor surfaces areas are the same.

So size, layout and construction methods combined are improtant. My point is that many folks sacrificed quality and efficency for square footage. They traded and extra $10,000 for another 500sqft or fancier cabinets and countertops, instead of increasing their R value, or using construction techniques to tighten their home.... or just hiring a better GC.

This has all been rambled on about before, but it's worth mentioning again.


BTW - we figure this is a starter home for my wife and I. Our gas and electric combined are around $1300 annually. But our electric rates are $0.12-0.15/kwhr. We don't open the doors or windows very much, and our winter temps are quite a bit colder than Arkansas with the summer not a lot cooler. We keep it a little cooler (66-70) in the winter, but a lot cooler in the summer (72-75) than you. We do have a partially finished basement that's heated as well. Our insulated is probably pretty poor in our walls, lots of leaks at the subfloor and no vapor barriers. But hey...energy was cheap... in 1967.

Ultimately our "baseline" without heating and cooling is still about $600-700 / year. That minimal electric use will be about the same no matter how big or small our home is. So even constructed to the best standard, I think we'd still be looking at a $1000 bill. He** the 2 sattelite DVR recievers I have use about $300/year in electricity alone... and the TV is probably consumes around $60/year. Computers another $50. Add 30% in the summer months to remove that heat too. Dont forget that electric clothes dryer. Figure a $1 per load. 5-6 loads per week. Yikes!


In another thread a university paper mention 200Watts for an internal load. I should clock my electric meter sometime when I'm not runing the A/C. I bet it closer to 400 or 500 Watts.

[jerryd_2008]

You'd probably fidn that all of thsoe smaller homes were either constructed before 1980, or were constructed cheaply. Sort of similar ot why compact cars in hte US are always cheap. ...

I was raised in a mining town where most of my friends lived in a half a company house. Never thought much of it then since it was common. Wonder more and more how did you get Mom, Dad and the 4 kids in bedrooms especially if there were boys and girls and they ranged from 5 to 17. Just to blow your mind, my folk's neighbor had 22 kids. Yes! That's what I said. Of course they had a big house. Right...! Still don't know where they slept and how they could and where they feed them. And then there were the girls having babies at the same time as Mom.

the point being that a 1500 sqft home built with the same techniques as the 2900 sqft home you mention would have a electric bill around $28-30.

I would scrape up the extra $40-30 = $120/year since I have to be able to cover the mortgage anyway.

... Cut off the top floor of a 2500 sqft homes and you heating and cooling bills may only drop by 30% or less because the exterior roof and floor surfaces areas are the same.

Then my wife would accuse me of being under her feet all of the time, not just occasionally. Besides, she watches soaps and I prefer more advanced entertainment. So 2 TV's don't fit well in one room.

... many folks sacrificed quality and efficency for square footage. They traded and extra $10,000 for another 500sqft or fancier cabinets and countertops, instead of increasing their R value, or using construction techniques to tighten their home.... or just hiring a better GC.

If you ever build a house ask the contractor just how much some desired improvements will cost. I couldn't believe the choices they make without even telling me the very modest savings (or is that profit) they just gave me.

Also, I recommend that you go to www.dougrye.com and order his tape on designing an energy-efficient home, only about $40. His son is an engineer and he will evaluate and suggest modifications to your plans for only a a fraction of a $1,000. think he will also guarantee your sub $100/month enegy bills also.

... Our gas and electric combined are around $1300 annually. But our electric rates are $0.12-0.15/kwhr. We don't open the doors or windows very much, and our winter temps are quite a bit colder than Arkansas with the summer not a lot cooler.

Ours is around $.10/kwhr. I would say there are 3-4 months here that are just beautiful with the doors open. In the Upper Midwest Spring and Fall came and went in about 2 weeks. In the far Northern Midwest, didn't need AC but you kept the furnace on the ready all year round.

...Ultimately our "baseline" without heating and cooling is still about $600-700 / year. That minimal electric use will be about the same no matter how big or small our home is. So even constructed to the best standard, I think we'd still be looking at a $1000 bill. He** the 2 sattelite DVR recievers I have use about $300/year in electricity alone...

Your baseline is ball park my guess too. You're not serious about your DVR's are you?

... Dont forget that electric clothes dryer. Figure a $1 per load. 5-6 loads per week. Yikes!

Wait until you get 3-4 kids, especially if they are girls that change into fresh clothes 2-3 times a day and take long showers too.

In another thread a university paper mention 200Watts for an internal load.

Get a Kill-A-Watt or similar. Some measure one plugged in device. Others can wrap around you meter and measure your entire house. Only a couple hundred too.

[motoguy128]

Your baseline is ball park my guess too. You're not serious about your DVR's are you?


Wait until you get 3-4 kids, especially if they are girls that change into fresh clothes 2-3 times a day and take long showers too.


Get a Kill-A-Watt or similar. Some measure one plugged in device. Others can wrap around you meter and measure your entire house. Only a couple hundred too.

The nameplate on the DVR's is arund 250Watts. Even at "idle" the hardisks are still running so it probably only drops to around 200 Watts. you could cut power to the unit when not in use... but sattelite aquisition takes about 2-3 minutes...longer in overcast weather (but I probbly need to get my dish alignment checked).

The TV is also about 250 Watts according to the nameplate.


For various reasons, we're sticking to having just 1 kid.

We'd still like more space and a better layout (full mater bath, walk-in closet... and a family room). We loved a 1500sqft layout my BIL had, ...although his HVAC (all flex) was the one of the worst hack jobs I've seen in person (new construction in Columbia, MO )... electric furnace... no heat pump!... combined with leaky flex in the attic meant a $400 bill in January... and he only kept it at 68F. He smartly walked away from a purchase agreement after renting it for 2 months.


Thought about getting one of those meters to better monitor my pwoer consumption. But ultimately I don't think my wife and I really want to change our habits much. I know where we're wasting energy, but not really interested in doing anything about it.

We save in other ways. Our combined annual mileage for all 3 vehciles (2 cars + motorcycle) is only about 12,000 miles. Real estate is cheap here (you can buy beautiful, historic 80-100 year old 4000+sqft mansions overlooking the Mississippi River on the bluff for under 300k... 1/3 of what it would cost to build it today using cheaper construction tehcniques), so our mortgage is about 1/3 of the amount we could get approved for. But we have debts from before we got married along with a fancy Hawaii trip we took last year. We also love our neighborhood and neighbors and moving to a different house means new problems. We just got this one fixed up and up to date.