Energy efficiency EER SEER HSPF COP

I'd like to talk now about energy

efficiency we have the ratings for room

air conditioners we have energy

efficiency ratings for residential

buildings and then we have heat pump

efficiency ratings and in all of these

we're going to use conversion factors

and this these two are the same

conversion factor just reciprocal one or

the other and so this one I'm going to

use a lot of which is one BTU per hour

that's a rate of cooling or rate of

heating is equivalent to zero point two

nine three watts okay so let's jump into

it so first is the energy efficiency

ratio ear EER its acronym it's defined

as that cooling rate of cooling divided

by the power input it has units of BTU

per hour that's then the traditional way

of describing or Quanah quantifying rate

of cooling divided by W dot which is the

rate at which you have to purchase the

power input to it electricity watts they

have the air-conditioning system will

run under controlled set of the

conditions so 35 degree outside 27

inside with 50% relative humidity inside

and they find that typical room air

conditioners can have an ear rating

between 8 and 10 maybe there's now more

than 10 but between 8 and 10 will be

their ear rating have you seen some

guides like this as little stickers you

want to buy some appliances the EPA the

US government came out with this and

it's caught on it's very popular you see

them have seen it for many years now and

they have a standard template so

basically it's a federal prohibition to

remove this tag unless you're the

consumer and you bought the product you

know if you're trying to sell the

product don't go and rip off all the

tags right and this is your Energy guide

to help consumers make good choices and

over here this is the Box the location

where the man you

sure puts in the model number and some

grading specifications and then over

here it's a description like okay that's

there's a lot of people selling room air

conditioners multiple manufacturers at

different sizes this is some description

oh it's with reverse cycle and it's with

louvered sides okay down here is a

visual image if you don't like numbers

you like graphs and they're saying hey

from the this is my yearly operating

cost estimated so if I bought a

different model I could probably spend

as low as that much an energy cost to

run this piece of equipment that I'm

thinking of buying or if I bought the

most efficient model out there I'd

probably be in this range from different

competitors but here's the one that I'm

looking at right now kind of like mpg on

your automobiles right range of vehicle

fuel economy here you have appliance

fuel economy's this is for a window air

conditioner but right down here they

have the ear as a number the ear energy

efficiency rate ratio is nine point five

for this now they have a lot of

qualifiers you can spend some time you

know depends on your utility rate data

and blah blah blah mount to use averaged

over the United States but there it is

alright I have a room air conditioner

with the rating of ear of nine point

five what is the coefficient of


here's multiple choice you're gonna need

to know that the ear has these units BTU

per hour per watt and you're gonna need

this energy conversion ratio of one B to

per hour as point two nine three watt

the first person to get my attention Inc

can answer this correct answer answer

this question correctly will be off the

hook for the rest of the lecture the EP

a little yellow rating sticker on the

appliance talks about ear you spent the

whole semester talked about Co P yes sir

hey he's good so definitely this were

kind of bogus down in here you knew it

was gonna be lower right there you go so

a it is then we move from window or room

air conditioners to what we call

residential air conditioners seer it's a

seasonal energy efficiency ratio and

what are they doing is they're averaging

some temperature conditions so it's not

always the extreme hot day and it's

trying to get better representation what

your actual energy use would be if you

bought this type of system and installed

it so how many people know how big the

air conditioning system is in the home

that they have lived in or their parents

owned or a friend owns or they'e

currently owned themselves how big is

your house how many square foot and how

big in tongues do is the air

conditioning system for at home one

person how big is your house you got

about 4 or 5 ton unit 5 ton and how many

square foot 3600 who okay that's pretty

efficient home pretty big home too you

probably have a pool and you know all

these friends have plus myself would

like to go to a pool party at that nice

house sometimes I can't resist myself of

an easy joke right all right what did

you have oh okay that's about right

little this sounds small but that's okay

she's got about a 14 little under 1500

square foot home with about a one and a

half ton unit so that sounds like it was

a pretty efficient system pretty good

windows sealed up pretty good otherwise

you're gonna be a strut it'll struggle

in the summer yeah who else nobody else

well in a couple more years when you

purchase homes you'll be in tune with

this alright did I tell you that this is

the lecture

to that you will get you more questions

some people come they graduate they go

away or they go home for vacation is Oh

what are you still on mechanical engine

what do you study in mechanical injury

list a bunch of topics and some of the

topics like that right up there on the

board what is that my boss transform

will get a big blank stare and maybe a

jaw drop like oh but then you're gonna

smash you something like thermodynamics

will you study the internal combustion

don't grab on I got a problem with my

car help me with my car yeah I know and

then the owner but I didn't study or

could I studied also air-conditioning

they'll grab on to you I got a problem

with my house my air conditioning my

house can you come over and help

diagnosis for me or they'll say things

like I'm making a big purchase my old

air conditioning systems going out can

you give me some advice because it's

gonna cost me thousands of dollars this

is serious business hasn't it already

happened to some of us yeah yeah anyway

so you can buy the lower efficiency

lower number seer or you can buy higher

efficiency higher number seer and the

seer has guess what the same units as

the ear it's how much beats you per hour

cooling per watt of electricity you

gotta buy so here is a visual guide your

EPA with the BOE you know joint venture

here this company makes it this is a

central air-conditioning system cooling

only and it has a split system we're

going to talk about split system in a

minute least efficient down here most

efficient over here they're showing you

the seer number 10 it's pretty low this

is old 13 would be right here and this

is a very high gonna cost you more money

for high-efficiency systems

way back when they used to sell lower

seer I remember when my dad he's paid

extra money and he put a 10 seer split

system for his house in San Antonio that

was a number of years ago you can't buy

a 10 seer anymore but he paid more money

for that high-efficiency unit and over

the years the engineers have been doing


work in air conditioning and moving up

that energy efficiency in 2015 federal

law came in effect basically saying if

you live in the southeast region the

United States you must have it 14 seer

that's the only ones legally they could

sell you where is the southeast region

the United States Alabama Arkansas

Delaware Florida Georgia Hawaii Hawaii

anyway Kentucky Louisiana Maryland

Mississippi North Carolina Oklahoma

South Carolina Tennessee and us and

Virginia those states use a lot of air

conditioning that's why now if you live

in another place it can still be a

minimum of 13 seer but and these rules

and laws continue to change so I don't

know if 2018 has something new for us or

not or 2020 probably does alright

somebody says I have a seer of 14 what

is the co P for refrigeration for that

system yes sir 4.1 this is a type of

question you'll get asked last summer

the electric bill to run the air

conditioning system was estimated be

three thousand dollars first of all they

usually don't meter only the air

conditioning system they metered a whole

house and you use electricity and a hot

water heater you use electricity and

your lighting maybe the stove maybe the

pool pump maybe some other things right

but somehow you're able to only get what

was used to provide air conditioning it

was only three thousand dollars over the

whole year the summer okay what you had

a seer of 13 and it's on its last leg

and you have to replace it and now you

can buy a seer 18 and the salesman

saying oh this will save you money

estimate the electric bill to run the AC

for next summer if you do buy that seer

of 18 this is a very good question so

what I'm going to do is I'm going to do

the same thing

I've got the answer covered up but I'm

gonna give you a second or two there's

the strategy everything laid out first

one to answer it 2200 there you go

so your savings is about eight hundred

eight hundred and thirty dollars per

year you can do a simple pay back you

know again this type of thing you will

be asked a lot to do after you get your

degree but I've been asked a lot about

things like this simple payback and

efficiency units well not only do we

have to struggle through the summer but

every now and then we have a winter that

we struggle through and a lot of the

northern part of the United States has a

lot more winter they have nine months of

winter instead of nine months of summer

sometimes and they have the heating

seasonal performance factor what is that

you know it has the same exact units

it's like a heat pump you're providing Q

dot into the warm dwelling to keep it

warm and you're having to pay for it pay

for the system to run it so instead of

being in watts per watt sits in these

BTU per hour

that's BTU per hour divided by watts the

unit's you can take a look US government

don't remove the label Energy Guide for

the consumer this is the making it their

model number of ratings over here is a

general description of classification oh

it's a heat pump it provides cooling and

heating meaning the same system in the

summer provides cooling same system in

the winter provides heating heat pump

how many people live in a house or have

lived at a house with heat pumps one two

that's it three four okay yeah my

daughter lives in one I don't that has a

heat pump that's the device that runs my

dad has one two okay they're getting

more and more common they were more and

more common in the northern middle part

let's say northern Texas middle part of

the United States where they have more

winter here we don't have enough winter

we still have a lot of lectric resistive

heating in San Antonio which is you

don't want that if you're living north

in in the middle let's say in Missouri

you don't want to have electric

resistive heating in Missouri or lower

Illinois or Kansas or something it would

just cost too much okay so here notice

that they give you the rating the seer

for the summer it's a 15 seer pretty

decent and they give you the heating

seasonal performance factor of 8.2 how

it's performing compared to others in

the winter because this system works

both alright question if the heat pump

has HS PF of 8.2 what is the co p no did

you already do it are you out for the

day okay do you want my attention you

want to give me the answer two

significant digits bingo you're done for

the day

congratulations and notice that we use

this conversion factor again and again

and again for both the ear the seer in

this heat pump performance factor

heating seasonal performance factor so

there you go those are very common this

is not really in the textbook but this

is what you'll be confronted with when

you lead this class and graduate right