40 SEER - Are they real?

[acdoctor]

EER implies a certain CoP in a static standard condition

a given heat pump will have a varying CoP with outside temperature and target delta T

me want graph of outdoor temperature vs CoP for like delta T of 5,10,15,20 degree Fahrenheit for a given aircon to get an idea of performance

These are produced for residential equipment. They should be out there for mini splits as well.

 

[Dzl]

EER implies a certain CoP in a static standard condition

a given heat pump will have a varying CoP with outside temperature and target delta T

I guess my point, or point where I need clarification, is that whatever CoP listed in the datasheet will also be based on a set of assumptions right?

If I understand correctly, COP = W of cooling per Wh of energy, whereas EER = BTU of cooling per Wh of energy.
EER is tested at 95*F / 50% humidity, COP appears not to be standardized in the same way, but its still only relative to the conditions it was tested at, right.

me want graph of outdoor temperature vs CoP for like delta T of 5,10,15,20 degree Fahrenheit for a given aircon to get an idea of performance

Yeah this would be ideal (it seems from the few datasheets i've looked at, datasheets often do give a bit of granularity with heating, but don't do this consistently with cooling). The Mitsubishi 6k for instance gives 1 SEER value, 1 EER value, no cooling COP, 1 HSPF value, and 5 different heating COP values for different temperatures. But a graph (or table) like you are describing sounds useful.

It looks like the Gree Sapphire 9k has a table somewhat similar to what you are describing, but the power numbers look off, I may be misunderstanding it

 

[acdoctor]

Here is a link to the Media 40 seer specs https://www.shareddocs.com/hvac/docs/1010/Public/04/328-12-0501-00.pdf

 

[sunshine_eggo]

EER = 3.41 x COP

If you're willing to use CoP, no reason to not use EER as it's a direct BTU/Wh number.

 

[Supervstech]

EER = 3.41 x COP

If you're willing to use CoP, no reason to not use EER as it's a direct BTU/Wh number.

True, but still at a specific set of conditions… heat transfer to a medium is based on thermal loads. What transfers at 95F won’t transfer the same at 85 or 100…
Home HVAC faces a lot of variables throughout the day, cooking, showering, home air leakage, solar gain, attic heat loads, Crawlspace humidity, draft effect, and many more… not to mention ambient conditions.
EER, SEER, COP, etc… all are a variable energy usage rating. Seer, attempts to show how miserly overall a system will perform, but it cannot tell you how well a 40vs. A 33 will be in every home. A 40 SHOULD consume less watthours over the day as a 38 or a 21, but under some conditions, a 20 can use less watthours than a 40, and others it can use more.
Over the entire year, a 40should average lower.

 

[curiouscarbon]

i’m an absolute loon and Watts(thermal)/Watt(electrical) is what i convert into for comprehension ?

to understand cooling load i think of it as a resistive heating in the negative direction in watts

100W cooling is like a 100W lightbulb’s heat but in the opposite direction ? sort of thing

 

[curiouscarbon]

I guess my point, or point where I need clarification, is that whatever CoP listed in the datasheet will also be based on a set of assumptions right?

Yes, when a manufacturer specifies a CoP it may be tied to some assumptions on operating conditions.

In general, any coefficient of performance ought to be specified along with some basic operating condition parameters, e.g. outdoor temp, outdoor relative humidity, indoor temp, indoor relative humidity, desired indoor temp, desired indoor relative humidity. or even just dT

Some graphs for compressors themselves are CoP vs RPM (rotating mechanism of compressor).

So yes there should usually be some contextual info along with a given CoP, afaik.

If I understand correctly, COP = W of cooling per Wh of energy, whereas EER = BTU of cooling per Wh of energy.
EER is tested at 95*F / 50% humidity, COP appears not to be standardized in the same way, but its still only relative to the conditions it was tested at, right.

EER to me is like a marketing speak thing
CoP to me is more of a fundamental physics thing
HVAC manufacturers do not seem to use Coefficient of Performance in any consumer facing material as far as I’ve seen. It’s mainly my weird notational preference, as BTU is meaningless to me but 1 watt is very intuitive.

Yeah this would be ideal (it seems from the few datasheets i've looked at, datasheets often do give a bit of granularity with heating, but don't do this consistently with cooling). The Mitsubishi 6k for instance gives 1 SEER value, 1 EER value, no cooling COP, 1 HSPF value, and 5 different heating COP values for different temperatures. But a graph (or table) like you are describing sounds useful.

It looks like the Gree Sapphire 9k has a table somewhat similar to what you are describing, but the power numbers look off, I may be misunderstanding it

neat! thank you for sharing.
the efficiency certainly does vary quite a bit over that range! down to 1.87 watts per watt in heating mode with outdoor temperature -22F! That’s like, only 87% better than a resistive heater. Meanwhile, the cooling at 80F outdoors is EER 10.1 or 10.1/3.412 = 2.96 CoP or 196% better than a resistive heater in the opposite direction, lol.

trying to conceptualize this stuff is challenging for me, keeping it all in Watts in my head makes thinking easier?

 

[Dzl]

EER to me is like a marketing speak thing
CoP to me is more of a fundamental physics thing

I don't know if this is a totally fair characterization. Since as @sunshine mentioned, EER is just COP in BTU/Wh
edit: actually I think I might get the distinction you are drawing.
I do agree though, its a hell of a lot more intuitive/easy to visualize the efficiency portion, when you stick to like units, Watts/Watts. Switch one side to BTU and it loses its intuitiveness (to me).

I wonder if as

HVAC manufacturers do not seem to use Coefficient of Performance in any consumer facing material as far as I’ve seen.

That's probably true (apart from datasheets--but lets be real, apart from us nerds.. consumers aren't touching datasheets with a 10ft pole, even on a DIY forum like this, I find a surprisingly large number of people who never think to crack open (or even download) the manuals and datasheets for their stuff. Half of what I do here is just figure out what component someone has, find the manual, and quote the relevant bits or interpret it for them ?

SEER seems like the best option for a single consumer friendly value to compare efficiency between AC's if we assume that people will not actually go into any depth (which is probably a reasonable assumption). But probably it could be improved upon. That paper I linked to earlier recommended regional SEER ratings or subratings to better reflect different climates, that seems like one reasonable option.

196% better than a resistive heater in the opposite direction

Lol, prefering COP and Watts is not weird to me... but this ^^ is cracking me up

I get what you are saying though.

 

[eXodus]

SEER seems like the best option for a single consumer friendly value to compare efficiency between AC's if we assume that people will not actually go into any depth

House insulation is rated and required in different zones throughout the country. Having a Single "consumer friendly" value is not doing the consumer much good - only the manufacturer since they only have to do one test and not 7 like for many other building materials.

EER to me is like a marketing speak thing
CoP to me is more of a fundamental physics thing
HVAC manufacturers do not seem to use Coefficient of Performance in any consumer facing material as far as I’ve seen. It’s mainly my weird notational preference, as BTU is meaningless to me but 1 watt is very intuitive.

COP makes sense, BTU is just a unit people got used to. (including me)
I started to to looking more into European and Asian designed A/C units and they exclusively have cooling/heating ratings in Thermal Watts.
What is difficulty for me - reading those spec sheets, Now you got at multiple spots the unit Watts,
BTU was easier to read in a sense that - you looked down the sheet - looked for the unit and found the line with cooling capacity.

I can go into a room and tell you by eye balling it - "that needs 12000 BTU conventional or a 8000 BTU inverter"
Not yet at that level for "Watts" but since that is only a fixed proportion I'm learning.

The next issue with this one Number standard I see - the Software which is controlling the variable speed Inverter components. Does it work the same in all environments? There are so many settings you can choose from today.
In the time of conventional units - there was ON and OFF - no adjustments in Fan speeds, compressor speeds and condenser.

My Window A/C Inverter - is so good - because it's soo humid.

Ew. Gross. I start to melt above 50%...

the Window A/C splashes the condensing water against the outside coils, which gives them an additional evaporative cooling.
I guess it would fare worse in a dry desert climate.

 

[curiouscarbon]

the Window A/C splashes the condensing water against the outside coils, which gives them an additional evaporative cooling.
I guess it would fare worse in a dry desert climate.

so awesome when units use the cold water condensation drain to cool the hot (refrigerant) condenser, both by conduction and evaporation ? efficiency boost!

 

[Supervstech]

so awesome when units use the cold water condensation drain to cool the hot (refrigerant) condenser, both by conduction and evaporation ? efficiency boost!

Window units do get an efficiency boost from condensate splashing, but I think it is more to save costs in manufacturing… minisplits, etc do not use the condensate, and they have far higher efficiency… and longevity.
Condensate water has a TON of contaminants in it, and the residue drastically shortens the life of the unit, but in a window unit, longevity isn’t the manufacturers goal… it's preventing water from damaging the wall the unit is poking through…

 

[curiouscarbon]

can confirm that midea small window unit does degrade relatively quickly from the water splashing and the fan.

it does fascinate me, e.g. for HEPA systems where the evap coil is directly after the filter stage

 

[Zoomyn]

I have been shopping HARD for two high rated HSPF5/6 units for a project barn/shop/house I've gotten... Almost leapt this fall yet still seeking more data before $pending money - and I am seeking another 6k or 9k btu one to tack onto my homebuilt van RV...

the efficiency certainly does vary quite a bit over that range! down to 1.87 watts per watt in heating mode with outdoor temperature -22F! That’s like, only 87% better than a resistive heater!

Only?

East of Fargo, ND - from 1 Sept to 15 Nov - grid power consumption total of 870 kwhrs with 600+ of those feeding my trusty Vornado resistance heater on its medium heat setting...

My camp was around a promaster van, with continual minor insulation improvements the best outdoors/indoors temperature differential I saw was 35*f and we saw 5*f overnight a few times...

My power outlet is fed from a lighting circuit, my one outlet 90-foot past the breaker panel fed through 14awg and then another 30-foot of extension cord...

Now if I could've gotten 1100 kWh heat versus 600 straight resistance.... since it wasn't -22*f probably more like 1500 kWh heat, my world would've MUCH nicer (or I'd have $50 more than I do)...

And at 5*f things on the van floor freeze solid, heater on or not

 

[curiouscarbon]

I have been shopping HARD for two high rated HSPF5/6 units for a project barn/shop/house I've gotten... Almost leapt this fall yet still seeking more data before $pending money - and I am seeking another 6k or 9k btu one to tack onto my homebuilt van RV...



Only?

East of Fargo, ND - from 1 Sept to 15 Nov - grid power consumption total of 870 kwhrs with 600+ of those feeding my trusty Vornado resistance heater on its medium heat setting...

My camp was around a promaster van, with continual minor insulation improvements the best outdoors/indoors temperature differential I saw was 35*f and we saw 5*f overnight a few times...

My power outlet is fed from a lighting circuit, my one outlet 90-foot past the breaker panel fed through 14awg and then another 30-foot of extension cord...

Now if I could've gotten 1100 kWh heat versus 600 straight resistance.... since it wasn't -22*f probably more like 1500 kWh heat, my world would've MUCH nicer (or I'd have $50 more than I do)...

And at 5*f things on the van floor freeze solid, heater on or not

good point, 87% increase is still almost double the heating for the energy

 

[eXodus]

Window units do get an efficiency boost from condensate splashing, but I think it is more to save costs in manufacturing… minisplits, etc do not use the condensate, and they have far higher efficiency… and longevity.
Condensate water has a TON of contaminants in it, and the residue drastically shortens the life of the unit, but in a window unit, longevity isn’t the manufacturers goal… preventing water from damaging the wall the unit is poking through…

that is true.
Yet the cost ($300-450 for 12000 BTU) and easy of installation make them still a compelling offering. And so far I have not seen a Window A/C which fails because of a coil corrosion issue (only close to the Ocean)

Usually they fail because of the electronics, Capacitor, Control Board - or one of the lines gets a pin hole and the Freon vents. Usually in a spot of high vibration close to compressor. Or the cheap metal enclosure gets so rusty that people don't want to look at them anymore

 

[acdoctor]

AHRI Air conditioning Heating and Refrigeration is a efficiency ratings organization that takes random samples from manufactures applying for ratings. And publishes those ratings. So always look for the AHRI rating. Without it who knows what it really is.

 

[Moldy1]

This thread is old however Id like to bring to attention that Midea and Carrier SEER 40 & 42 units are actually the same.

"Did you know? Midea and Carrier have a partnership that uses Midea’s Toshiba technology in Carrier-branded mini split. As a result, Midea mini split systems are often called Midea Carrier mini split systems."

Midea Mini Split Heat Pump/AC Reviews and Prices 2022 - PICKHVAC

Who Makes Midea Mini Split Units? Midea is a globally significant appliance manufacturer that specializes in air conditioning units, refrigerators, washers and dryers, and dishwashers. Headquarters for Midea are in China, and the company has over 100,000 employees. There are also many popular...

www.pickhvac.com

Each unit is different in every house no matter how efficient it is. air sealing/insulation levels / thermal breaks in wall studs etc.
GREE / Carrier / Midea are very efficient, they can ramp down the rpm on compressor,& the EEV can regulate the refrigerant flow now.

Koldsimer --> "These mini split systems tend to ramp up for a short time then settle into a lower energy consumption mode in most conditions. I imagine that those 40 seer numbers are somehow fudged by using these low usage times to represent their energy consumption. My pioneer can put out cool, refrigerated air running on around 200 watts. The heat pump can put out warm on running on as little as 300 watts."

That is darn good numbers, that is good for a 2000w inverter and a couple of Lg solar panels along with a few batteries, panels run by day, batteries by night, hopefully these units cycle off to standby or low power for when is ever goes off.

 

[CryptoTech]

I see that Sig Solar has an EG4 Hybrid AC/DC 12000 BTU for $1299. Has anyone used one of those? It doesn't mention the seer rating, but they have 220 units that are 38 seer. I can't find any user info.

 

[rustythorn]

new SEER ratings and testing methods are starting next year under SEER2 so things might change up a bit

 

[Vigo]

I see that Sig Solar has an EG4 Hybrid AC/DC 12000 BTU for $1299. Has anyone used one of those? It doesn't mention the seer rating, but they have 220 units that are 38 seer. I can't find any user info.

I'd like to know too. And I wonder how much has really been done to power the unit 'directly from solar'.. As far as I know anything that converts ac to DC through a rectifier, you can also just feed DC to at the same voltage it would normally be post-rectifier, and the DC will just flow through the rectifier section ignoring it, and everything downstream is none the wiser that it's being fed from an actual DC source. So does this unit just have mc4's paralleled off the power feeds and then say in the manual your array must produce X voltage which is coincidentally the same as rectified 120 or 240? Like 170vdc or 330vdc? Because if that's all that's done I can splice in my own mc4's thank you very much ?