Will 16 SEER air conditioning systems become standard on new Phoenix area homes? (Gilbert: home builders, heat pump)

[Pink Jazz]

Ever since the beginning of the Energy Star Homes craze, most Phoenix area builders now include 14 SEER air conditioning systems standard. However, now that 14 SEER is the minimum federal standard for our state, does anyone think 16 SEER AC systems will eventually become standard on new homes? After all, the point of the Energy Star program is to exceed minimum efficiency standards.

Typically, the only difference between a 14 SEER vs. 16 SEER system is the use of an ECM blower in the furnace or air handler. This is what builders typically do in their 14 to 16 SEER upgrade option, while using the same outdoor condenser.

I know that Fulton is offering a 16 SEER system standard at their new Warner Groves at Morrison Ranch community in Gilbert, however, I am not sure if this will become the norm in future Fulton communities. I haven't researched other builders if they are offering 16 SEER systems standard yet.

If builders do make 16 SEER systems standard, I also wonder if higher SEER systems will become available as upgrades. Systems higher than 16 SEER will generally require a different model of condenser (such as a Carrier Performance or Infinity series), so instead of changing the furnace or air handler, such upgrades would instead change the condenser.

So, does anyone think 16 SEER AC systems will become the norm on new Phoenix area homes?

[wit-nit]

Yes they will in a few years, and then in a few more years it'll go higher again.
We have a 19 seer now and it's fantastic.

[Pink Jazz]

Originally Posted by wit-nit

Yes they will in a few years, and then in a few more years it'll go higher again.
We have a 19 seer now and it's fantastic.

It will be several years before the next Energy Star standards are released, so I don't see it going higher than 16 SEER anytime soon. However, more builders could soon start offering upgrades for systems of 17 SEER or higher.

I also wonder if more tract home builders will reconsider using heat pumps instead of an AC+gas furnace. I know that prior to the housing market crash, some tract builders did experiment with heat pumps in lieu of an AC+gas furnace (even in communities with gas service), however, it seems that many have reverted to using AC+gas furnaces except in all-electric communities without gas service. Most new custom homes, as well as most replacement systems use heat pumps, so I wonder why many tract builders continue to use gas furnaces. I don't expect Phoenix area builders to use 90%+ AFUE condensing furnaces due to their higher installation costs and poor ROI in our climate, so perhaps they will be left with no choice but to use a heat pump. The typical tract home installation here in the Phoenix area is to install the furnace in the attic, which is generally not recommended for condensing furnaces due to the potential for the condensate line to freeze.

[hikernut]

For cooling, the cost of the equipment is enormous. The new systems we just installed, amortized out across all of the cooling months during the expected life, is perhaps $250-$300 per month. The cost of the system is probably more than the cost of the electricity it will use during its lifetime.

I won't spend thousands of extra dollars on a system that will (maybe) save us a couple hundred bucks a year. The machines they are selling today are absolute junk.

[Zippyman]

The seer rating in our climate is basically worthless. 80% of the seer rating is weighted towards efficiency at temps under 80 degrees, which is where We actually start to turn our a/c units on. In warm & humid climates where they might run the air in 76 degree weather (because of humidity), it's a much more accurate measure of efficiency. At 100 degrees & 10% humidity, the performance / efficiency charts for an 8 seer & an 18 seer look almost the same.

Nobody seems to talk about this, but the data is actually *in* the installer's manual for every unit (the installer needs to know both the line pressure & the projected amp-draw at a given outdoor temp to verify the refrigerant charge). I've downloaded these manuals in the past & actually done the math for my own house (seer 14 vs seer 18), and the savings are truly underwhelming. To slightly oversimplify, amps = quarters & a 14 seer & an 18 seer draw almost the same amount of "quarters" per hour at 90, 100, or 110 degrees.

It's kinda like if the "efficiency ratings" for cars were figured at 20 mph. Nobody really drives at 20mph sustained (unless you get stuck on the I-10 everyday lol!), so people would reject those ratings. Seer ratings might as well be "performance on Jupiter " ratings, because they don't tell you anything meaningful if you live in the desert.

Further, you wouldn't even try to measure fuel "efficiency" in a car that had a leaking gas tank, and our houses have a "built in" duct-leakage of 10-15% (if we're lucky!) - only the newest, tightest houses have a leakage rate of less than 10%. Putting a 18 seer unit on a 30 year-old house is just like having a Prius with a leaky fuel tank. You're saving some & losing more..

There's a *huge* bump in efficiency (in our climate) when you go to dual-stage units though..
If they made dual-stage 14seer units, we could save big piles of cash here.

That said, seer ratings are backed by the government, so people buy into the myth, even if it saves nothing.

[Pink Jazz]

Originally Posted by Zippyman

The seer rating in our climate is basically worthless. 80% of the seer rating is weighted towards efficiency at temps under 80 degrees, which is where We actually start to turn our a/c units on. In warm & humid climates where they might run the air in 76 degree weather (because of humidity), it's a much more accurate measure of efficiency. At 100 degrees & 10% humidity, the performance / efficiency charts for an 8 seer & an 18 seer look almost the same.

Nobody seems to talk about this, but the data is actually *in* the installer's manual for every unit (the installer needs to know both the line pressure & the projected amp-draw at a given outdoor temp to verify the refrigerant charge). I've downloaded these manuals in the past & actually done the math for my own house (seer 14 vs seer 18), and the savings are truly underwhelming. To slightly oversimplify, amps = quarters & a 14 seer & an 18 seer draw almost the same amount of "quarters" per hour at 90, 100, or 110 degrees.

It's kinda like if the "efficiency ratings" for cars were figured at 20 mph. Nobody really drives at 20mph sustained (unless you get stuck on the I-10 everyday lol!), so people would reject those ratings. Seer ratings might as well be "performance on Jupiter " ratings, because they don't tell you anything meaningful if you live in the desert.

Further, you wouldn't even try to measure fuel "efficiency" in a car that had a leaking gas tank, and our houses have a "built in" duct-leakage of 10-15% (if we're lucky!) - only the newest, tightest houses have a leakage rate of less than 10%. Putting a 18 seer unit on a 30 year-old house is just like having a Prius with a leaky fuel tank. You're saving some & losing more..

There's a *huge* bump in efficiency (in our climate) when you go to dual-stage units though..
If they made dual-stage 14seer units, we could save big piles of cash here.

That said, seer ratings are backed by the government, so people buy into the myth, even if it saves nothing.

Does this take into account the use of PSC vs. ECM blowers in the furnace or air handler? Often the only difference between a 14 SEER and a 16 SEER system is that the former uses a PSC blower while the latter uses an ECM blower, while using an identical condenser. ECM blowers are inherently more efficient than PSC blowers.

[DougStark]

Zippy, you make an excellent point. SEER rating is a joke for our climate. At 100 degrees and above, all air cooled condensers lose their efficiency. The hotter it is, the harder they work to cool the refrigerant.

If the A/C industry was serious about residential energy efficiency in super hot climates like ours, they'd design and market water-cooled condensers for homes (big buildings are cooled this way.) A little company offered one (Freus?), but I don't think they're in business anymore.

[hikernut]

Originally Posted by DougStark

If the A/C industry was serious about residential energy efficiency in super hot climates like ours, they'd design and market water-cooled condensers for homes (big buildings are cooled this way.) A little company offered one (Freus?), but I don't think they're in business anymore.

No, they're not a going concern any longer. We purchased a home that had a Freus system. It was a real headache. The hard water here causes lots of problems and the systems do not have much of a lifespan. Ours made it to ten years which I gather is quite heroic. The service guy that worked on it said he'd never seen one more then seven years old until he came to our house. Good in theory, not so good in practice.

Another idea is to make ice or chilled water at night, when the air temperature is a little less and the electric rates are lower (if on a time of use plan). I think some commercial systems work like this, but I suppose it's not practical for a (smaller) residential application?

[DougStark]

hiker, you're right. The minerals in the water here are the major problem for water cooled condensers for residential use. Technicians servicing commercial applications (cooling towers) know all about this problem. But the geniuses employed by the major HVAC mfrs. should be able to come up with something.

[stevek64]

Originally Posted by DougStark

hiker, you're right. The minerals in the water here are the major problem for water cooled condensers for residential use. Technicians servicing commercial applications (cooling towers) know all about this problem. But the geniuses employed by the major HVAC mfrs. should be able to come up with something.

I think they did.......planned obsolescence.....for the obvious reason.

Originally Posted by Zippyman

The seer rating in our climate is basically worthless. 80% of the seer rating is weighted towards efficiency at temps under 80 degrees, which is where We actually start to turn our a/c units on. In warm & humid climates where they might run the air in 76 degree weather (because of humidity), it's a much more accurate measure of efficiency. At 100 degrees & 10% humidity, the performance / efficiency charts for an 8 seer & an 18 seer look almost the same.

Nobody seems to talk about this, but the data is actually *in* the installer's manual for every unit (the installer needs to know both the line pressure & the projected amp-draw at a given outdoor temp to verify the refrigerant charge). I've downloaded these manuals in the past & actually done the math for my own house (seer 14 vs seer 18), and the savings are truly underwhelming. To slightly oversimplify, amps = quarters & a 14 seer & an 18 seer draw almost the same amount of "quarters" per hour at 90, 100, or 110 degrees.

It's kinda like if the "efficiency ratings" for cars were figured at 20 mph. Nobody really drives at 20mph sustained (unless you get stuck on the I-10 everyday lol!), so people would reject those ratings. Seer ratings might as well be "performance on Jupiter " ratings, because they don't tell you anything meaningful if you live in the desert.

Further, you wouldn't even try to measure fuel "efficiency" in a car that had a leaking gas tank, and our houses have a "built in" duct-leakage of 10-15% (if we're lucky!) - only the newest, tightest houses have a leakage rate of less than 10%. Putting a 18 seer unit on a 30 year-old house is just like having a Prius with a leaky fuel tank. You're saving some & losing more..

There's a *huge* bump in efficiency (in our climate) when you go to dual-stage units though..
If they made dual-stage 14seer units, we could save big piles of cash here.

That said, seer ratings are backed by the government, so people buy into the myth, even if it saves nothing.

Shhhh....you're going to cut into the bottom line of some out there with that kind of straight talk.