40 SEER - Are they real?

[Riley]

https://www.djscompanies.com/carrier-infinity-series-ductless-up-to-42-seer-system.html

Midea 9000 Btu 40 SEER Mini Split Hyper Heat Pump AC

MAX SERIES/ 40 SEER / 220V This Package Includes: (1) Indoor Unit : ( DLFPH )AH09XAK DLFPH Features Include : Relative Humidity Sensor Set the desired relative humidity in 5% increments. Occupancy Sensor 'EYE' can send airflow twords or away from people in the room. 9 Modes Cool, Heat, Dry, Fan...

www.minisplitwarehouse.com

It seems there is some mini-split only uses half of the energy compared to a Mr. Cool or Pioneer. I am seriously thinking about returning my Pioneer and getting a 40 SEER mini split because the solar system won't offer me enough power to run a 21 SEER Pioneer.

But that's a lot of work, and I need to pay 3x the price to get a Midea. Does anyone know their numbers are real, and you can really expect to use only 50% energy compared to a Pioneer??

One thing I noticed is that Pioneer had 14 EER and CARRIER Infinity had 15 EER, so their difference is only SEER: 21 VS 42

I wondered if I should spend that $1500+ to get a better mini-split or just to get more batteries. More solar panels aren't an option because the roof is full.

 

[sunshine_eggo]

I'm dubious primarily because of "Up to 40 SEER". I read that as the unit can be extremely efficient in certain ideal scenarios, but I would expect the typical SEER would be lower - in the 20/low 30s for sure. Almost all references I can find put high SEERs on ductless mini-splits to be not higher than 30.

This unit is 230VAC, which typically have higher efficiency over 120VAC units.

From:

https://d11fdyfhxcs9cr.cloudfront.net/templates/32505/myimages/cmna_jg/max_series_specs_w_sensor.png

It also doesn't make sense that their SEER ratings are 40/30 (25% difference) vs. EER ratings 15/13.5 (10% difference)

SEER takes into account seasonal variations. EER is a hard number, i.e., it's a test standard with fixed temperatures/humidity:

The energy efficiency ratio (EER) of a particular cooling device is the ratio of output cooling energy (in BTUs) to input electrical energy (in watt-hours) at a given operating point. EER is generally calculated using a 95 °F (35 °C) outside temperature and an inside (actually return-air) temperature of 80 °F (27 °C) and 50% relative humidity.

So, for the given conditions:
The 9000 BTU/hr unit with EER of 15 is going to consume 600W of power.
The 12000 BTU/hr unit with EER of 13.5 is going to consume 889W of power.

33% more cooling for 48% more energy.

That's a pretty small difference in comparison to their SEER rating.

I looked up a 9000 BTU 230VAC SEER 22.8 Pioneer unit, and it has an EER of 14, so the Midea will out perform it, but only by about 7%:

Pioneer 9000/14 (SEER 22.8) = 643W vs. 600W for the Midea (SEER 40)

Somethin' fishy 'bout that Midea SEER number.

 

[Dzl]

As far as I know, there is only one A/C over 40 SEER, which is made by Carrier, and about a half dozen others between 30-40 SEER. Do I recall correctly that Carrier and Midea are related brands?

I've never been able to fully understand SEER ratings. I try, but my eyes quickly glaze over. I think COP and EER are rather straightforward, SEER is a bit more complicated.

I had a spreadsheet comparing the SEER / EER / COP / HSPF and Watt ratings of some of the most efficient small minisplits on my desktop, but I don't think I ever got around to transfering it over to my laptop which is all I have right now.

 

[Riley]

I'm dubious primarily because of "Up to 40 SEER". I read that as the unit can be extremely efficient in certain ideal scenarios, but I would expect the typical SEER would be lower - in the 20/low 30s for sure. Almost all references I can find put high SEERs on ductless mini-splits to be not higher than 30.

This unit is 230VAC, which typically have higher efficiency over 120VAC units.

From:

https://d11fdyfhxcs9cr.cloudfront.net/templates/32505/myimages/cmna_jg/max_series_specs_w_sensor.png

It also doesn't make sense that their SEER ratings are 40/30 (25% difference) vs. EER ratings 15/13.5 (10% difference)

SEER takes into account seasonal variations. EER is a hard number, i.e., it's a test standard with fixed temperatures/humidity:

The energy efficiency ratio (EER) of a particular cooling device is the ratio of output cooling energy (in BTUs) to input electrical energy (in watt-hours) at a given operating point. EER is generally calculated using a 95 °F (35 °C) outside temperature and an inside (actually return-air) temperature of 80 °F (27 °C) and 50% relative humidity.

So, for the given conditions:
The 9000 BTU/hr unit with EER of 15 is going to consume 600W of power.
The 12000 BTU/hr unit with EER of 13.5 is going to consume 889W of power.

33% more cooling for 48% more energy.

That's a pretty small difference in comparison to their SEER rating.

I looked up a 9000 BTU 230VAC SEER 22.8 Pioneer unit, and it has an EER of 14, so the Midea will out perform it, but only by about 7%:

Pioneer 9000/14 (SEER 22.8) = 643W vs. 600W for the Midea (SEER 40)

Somethin' fishy 'bout that Midea SEER number.

If we look at EER only , this one seems to be the highest I can find -- 19.05 EER : https://ashp.neep.org/#!/product/34424

 

[Dzl]

If we look at EER only , this one seems to be the highest I can find -- 19.05 EER : https://ashp.neep.org/#!/product/34424

High EER and high SEER

 

[curiouscarbon]

As far as I know, there is only one A/C over 40 SEER, which is made by Carrier, and about a half dozen others between 30-40 SEER. Do I recall correctly that Carrier and Midea are related brands?

I've never been able to fully understand SEER ratings. I try, but my eyes quickly glaze over. I think COP and EER are rather straightforward, SEER is a bit more complicated.

I had a spreadsheet comparing the SEER / EER / COP / HSPF and Watt ratings of some of the most efficient small minisplits on my desktop, but I don't think I ever got around to transfering it over to my laptop which is all I have right now.

EER is at one temperature and one humidity i thought

SEER is the same but a weighted average over a number of different combinations of temperature and humidity numbered N over the season.

so it’s like (EER1+EER2+EER3)/3 for three combinations of temp and humidity

someone please correct me, i’m an amateur, not an hvac tech.

---

3.412 BTU/hr per 1 Watt thermal is what i remember

40 SEER is equivalent to approximately 11.7 thermal watts pumped per 1 electrical watt power input. which is a peak Coefficient of Performance of 11.7!!! Over 10!

Existing aged HVAC in USA seems to be like CoP 2-4.

Modern mini split and other efficient seem to be like CoP 4-6.

CoP 10 is magic to me and I don’t know how to consistently achieve it over a wide range of temperatures and humidities (-20C to 60C, 10-100% RH)

Refrigerant pumping can be very efficient. Wonder what the CoP vs delta temperature is.

 

[Dzl]

EER is at one temperature and one humidity i thought

SEER is the same but a weighted average over a number of different combinations of temperature and humidity numbered N over the season.

so it’s like (EER1+EER2+EER3)/3 for three combinations of temp and humidity

someone please correct me, i’m an amateur, not an hvac tech.

Looks like youve got it right. From Wikipedia:

Relationship of SEER to EER and COP​

The energy efficiency ratio (EER) of a particular cooling device is the ratio of output cooling energy (in BTUs) to input electrical energy (in watt-hours) at a given operating point. EER is generally calculated using a 95 °F (35 °C) outside temperature and an inside (actually return-air) temperature of 80 °F (27 °C) and 50% relative humidity.

The EER is related to the coefficient of performance (COP) commonly used in thermodynamics, with the primary difference being that the COP of a cooling device is unit-less, because the numerator and denominator are expressed in the same units. The EER uses mixed units, so it doesn't have an immediate physical sense and is obtained by multiplying the COP (or EER) by the conversion factor from BTUs to watt-hours: EER = 3.41214 × COP (see British thermal unit).

The seasonal energy efficiency ratio (SEER) is also the COP (or EER) expressed in BTU/watt-hour, but instead of being evaluated at a single operating condition, it represents the expected overall performance for a typical year's weather in a given location. The SEER is thus calculated with the same indoor temperature, but over a range of outside temperatures from 65 °F (18 °C) to 104 °F (40 °C), with a certain specified percentage of time in each of 8 bins spanning 5 °F (2.8 °C). There is no allowance for different climates in this rating, which is intended to give an indication of how the EER is affected by a range of outside temperatures over the course of a cooling season.

 

[curiouscarbon]

thank you for investigating this;

according to this reference,

65F to 104F
18C to 40C

8 bins or “weather grades”
5F granularity
2.8C granularity

in terms of how the SEER is actually calculate

Histogram - Wikipedia

en.wikipedia.org

 

[Koldsimer]

My experience with my Pioneer 12kbtu has taught me a couple things.... 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.

I considered getting just one of the super high seer (30+) midea, carrier or Mitsubishi units but i was able to get two of the pioneer units for less money and I couldn't be happier.

The only complaint i have is that i wish there was a way to override the thermostat and have individual control over the compressor. It would be nice to just run it at say 10% for a fixed time. It would make load calculations and estimates easier and more accurate.

 

[eXodus]

https://www.djscompanies.com/carrier-infinity-series-ductless-up-to-42-seer-system.html

Midea 9000 Btu 40 SEER Mini Split Hyper Heat Pump AC

MAX SERIES/ 40 SEER / 220V This Package Includes: (1) Indoor Unit : ( DLFPH )AH09XAK DLFPH Features Include : Relative Humidity Sensor Set the desired relative humidity in 5% increments. Occupancy Sensor 'EYE' can send airflow twords or away from people in the room. 9 Modes Cool, Heat, Dry, Fan...

www.minisplitwarehouse.com

It seems there is some mini-split only uses half of the energy compared to a Mr. Cool or Pioneer. I am seriously thinking about returning my Pioneer and getting a 40 SEER mini split because the solar system won't offer me enough power to run a 21 SEER Pioneer.

But that's a lot of work, and I need to pay 3x the price to get a Midea. Does anyone know their numbers are real, and you can really expect to use only 50% energy compared to a Pioneer??

One thing I noticed is that Pioneer had 14 EER and CARRIER Infinity had 15 EER, so their difference is only SEER: 21 VS 42

I wondered if I should spend that $1500+ to get a better mini-split or just to get more batteries. More solar panels aren't an option because the roof is full.

I really don't like SEER and EER. It's a weird North American standard. Which is only applicable to a small range of climates and applications.

Existing aged HVAC in USA seems to be like CoP 2-4.

Modern mini split and other efficient seem to be like CoP 4-6.

CoP 10 is magic

this here. I care about - how many BTU of cool do I get for 1 WH.

For instance, my roof A/C of my RV:

13500BTU / 1200WH = 11.25 BTU/WH

Regular Window A/C
5000BTU / 350W = 14 BTU/WH

My Midea Window Inverter:
12000BTU / 600WH = 20 BTU/WH

It seems there is some mini-split only uses half of the energy compared to a Mr. Cool or Pioneer. I am seriously thinking about returning my Pioneer and getting a 40 SEER mini split because the solar system won't offer me enough power to run a 21 SEER Pioneer.

Is your Pioneer a inverter? Changing from one inverter to another - shouldn't be a crazy difference.

So far I also noted - all inverters I installed outperforming similar sized conventional units in the humid climate of Florida.
The factor is about 1.4-2 I've replaced a 3 Ton A/C (36000BTU) unit with a 20000BTU inverter - which is cooling better.

 

[sunshine_eggo]

I really don't like SEER and EER. It's a weird North American standard. Which is only applicable to a small range of climates and applications.

I get your dislike of SEER, I'm with you, but why EER? EER is a specific BTU/Wh value for 95°F outdoor and 80°F indoor, 50% humidity.

this here. I care about - how many BTU of cool do I get for 1 WH.

For instance, my roof A/C of my RV:

13500BTU / 1200WH = 11.25 BTU/WH

That varies with conditions. Sure, you may burn a pretty steady 1200W, BUT as conditions change, so will your BTU/h flux.

Regular Window A/C
5000BTU / 350W = 14 BTU/WH

My Midea Window Inverter:
12000BTU / 600WH = 20 BTU/WH

Same is true for the above. It's subjective as the BTU/Wh will change with conditions.

Is your Pioneer a inverter? Changing from one inverter to another - shouldn't be a crazy difference.

So far I also noted - all inverters I installed outperforming similar sized conventional units in the humid climate of Florida.
The factor is about 1.4-2 I've replaced a 3 Ton A/C (36000BTU) unit with a 20000BTU inverter - which is cooling better.

That's good to know. My gut says that it's their relatively steady operation vs. on/off that allows for a continual reduction in humidity.

 

[Supervstech]

My take on high seer equipment is dehumidification at low cooling needs raises their seer...
So in dry areas, high seer equipment doesnt...

 

[Dzl]

Seems like both have their pros/cons:
COP & EER are 'hard numbers' / easy to understand values. There is something to be said for simplicity and easy to understand numbers. But at the same time, basing efficiency numbers off a single test condition, may not be very representative of the full range of real-world conditions, and may even be misleading.
SEER on the other hand is harder to understand / less intuitive (for layfolk like me at least), but makes an attempt to establish an indicator of efficiency over a range of conditions. Still won't be representative of all conditions/climates, but maybe a better indication of real world efficiency (at least for a certain climate), I just wish it was a little less opaque.

 

[eXodus]

I get your dislike of SEER, I'm with you, but why EER? EER is a specific BTU/Wh value for 95°F outdoor and 80°F indoor, 50% humidity.

100% humidity where I'm for most of the cooling seasons.

That's good to know. My gut says that it's their relatively steady operation vs. on/off that allows for a continual reduction in humidity.

you just answered your question. EER is not comparable between inverter and conventional units for a real world environment.

Who ever makes those standards need to include a regular daily temperature cycle to test A/C units. Start with 70F outside in the morning - warm up 95F and go down gain. It's really not that difficult to program a ramp like that.

The primary issue with that EER standard is - it's a full load no changes scenario. While in nothing in the weather of the real world is ever constant. I mean it's better then nothing - but was defined in a time when A/C units still worked differently.

 

[Dzl]

Relevant paper I found on SEER, the methodology, the limitations, and some discussion of scenarios where it is and isn't a good metric, and ways to improve it.

One takeaway, one of the climates its least useful for is hot + dry, such as the US southwest.

 

[eXodus]

efficiency numbers off a single test condition,

That is what like never happens in the world.

It's like Dieselgate perfect on the test but, awful when used like most people would use it.

 

[sunshine_eggo]

100% humidity where I'm for most of the cooling seasons.

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

you just answered your question. EER is not comparable between inverter and conventional units for a real world environment.

Except this thread is comparing mini-splits, but I get your point.

 

[Dzl]

just answered your question. EER is not comparable between inverter and conventional units for a real world environment.

How is COP superior to this though? COP is also just based on some static condition is it not? Or am I misunderstanding?

 

[curiouscarbon]

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

 

[acdoctor]

I am a HVAC contractor and I have the high seer 1 ton Madia marketed through Heil in my shop running right now. If memory serves the 9k in the only one that is 40 Seer the 12k is 38. In my house I have 2 12k 33 Seer Fujitsu. Also have a 12k 26 Seer in a out building.They all sip electricity. It’s hard to use a amp meter to compare they are always in flux. SEER does make a difference and is real though.