HVAC BTU and Ton

[henrym02]

thank you, simple formula but works great

[DrZarkloff]

@henrym02 Thanks for watching.

[AZtuber1]

DrZarkoff, I just want to thank you for your great videos. I am currently a student at The Refrigeration School (RSI) in Phoenix, Arizona. We watch your videos in class. They are very useful. Thanks again and keep them coming!

[DrZarkloff]

@AZtuber1 Thank you very much for watching my videos. Please say hello to your class for me.

[stevieb031969]

I knew 12,000 btu was a ton,it helped seeing the model # with the two letter rating for tonnage.

[sqhunters]

Hi DrZarkloff.please help me with this.I was deployed to service a window casement unit.after cleaning the coils.I fitted it back in the frame.I switched on and there is cold air blowing in and hot blown out by the other blower.surprisingly it doesn't cool the room even after running it for an hour.not even a bit.can u please educate me in troubleshooting this problem.thanks very much.

[DrZarkloff]

@sqhunters If the coils are already clean then the problem is probably with the compressor. Time for a new unit.

[amberlynn6914]

@cdelacruz808dsm your Trane unit is a 5 ton..

[jjpjjpjjp1]

@DrZarkloff thanks

[Jamieinchains]

Good vid!

[DrZarkloff]

@cdelacruz808dsm You'll really need to call a parts house that has that info handy.

[braulio1350]

Do you know how many calls a part house will get a day if people followed your advice.

[DrZarkloff]

@braulio1350 I'm not sure. I hope they can make many sales.

[nynick11223]

I want to say that ur videos are great. Please keep up the good work. I would like to see you test the reversing valves, and replace one. Thank you.

[DrZarkloff]

@nynick11223 Thanks for watching.

[m57yugo]

hello are you still making videos I sure would love to see some simply things done like changing a filter drier with using a passive recovery.a lot of home owners don't know about how to switch between cool and heat for there belt driven adjustable pulley that would be a good video.you make some great videos keep up the good work.

[jjpjjpjjp1]

i would like to find the tonnage for a - lets say- 10x10x7 walk in cooler and or freezer???? please would like a rule of thumb way i can get the size of condensing unit for it and possible evaporator size

[DrZarkloff]

@jjpjjpjjp1 You could go to Johnstone Supply and ask them to calculate the horsepower size system that you'll need. Refrigeration systems are rated in horsepower instead of BTU.

[sqhunters]

Hello Dr Zarkloff,Can you help me with this problem.I have a multi split R22 system that has three units attach .Everytime i switch on this particular unit (thats attached to one of the two compressors) the ELCB trips after 8 minutes.Tested the capacitors and the rest of things and they are fine.Can you please enlighten me.

[DrZarkloff]

@sqhunters Have you mega ohmed your motors and compressors?

[1edbtz]

Hay my frind

[stoutair01]

you are the man. thanks for all the advice

[pitolove71]

Dr. Zarkloff!!! Hey, this is Ariel. I wrote you a few months ago on advice in taking an HVACR Technician course. Well, I did the research & took your advice!! I started school today & I'm really excited about this. I'm in Florida and HVAC techs are in high demand. By the way I'm one of the minorities that you posted are hard to find in this industry. The pay is attractive & the work is great!! Thank you for your advice & I'm subscribing to your channel because I want to learn from the best!!!

[DrZarkloff]

@pitolove71 Thank you for watching. I wish you the best in school.

[sqhunters]

Hello Dr Zarloff.I have a problem with a National multi split unit.The compressor doesnt cut in for one of the unit.When i remove the refrigerant it runs well.As i load in the refrigerant it just shuts down.I have checked the transformers,compressors,conta­ctors,capacitors,blower fan and they are all working fine.I suspect the pc board is down.Can you enlighten me further.I have also set the thermostat to cool on this R22 non inverter system.Thanks in advance.

[DrZarkloff]

@sqhunters You've described to me exactly what happens when I rotary compressor has gone bad. It could have been because of an overcharge or the compressor is just old and wore out.

[jlsalazar101]

Hello Dr Zarloff this is the first posting addressed to you . Your knowledge is real extensive keep it up. I have a question perhaps you could help. My unit had a frosted suction line starting at the condenser and eventually it works its way to the evaporator. The low side psi is 54 and the high side is 260. My vent temp is around 49 degrees. All media is clean filter, evaporator etc. Besides a dirty filter or coil or low refrigerant what else would cause this problem?

[DrZarkloff]

@jlsalazar101 You might want to check the blower wheel and motor to see if it's clean and working properly. Also, clean the evaporator coil. Even if it looks clean from the outside, it could be dirty on the inside.

[jlsalazar101]

@DrZarkloff The blower appeared to be working properly there was plenbty of air flowing through the vents. Someone lowers the thermostat way too low would this cause the line to freeze up.?

[DrZarkloff]

@jlsalazar101 Yes, the evaporator could ice up if the thermostat is left below 65 F.

[jlsalazar101]

@DrZarkloff You are the undisputed man it definetly was the blower motor. The curious thing was the amperage was good but I did notice the motor get real hot.When I took out the blower motor I noticed some play in the shaft...Thanks alot for the help..keep up the good work.

[DrZarkloff]

@jlsalazar101 I'm glad to have helped.

[thisisnotyours1]

Thank you....

[merodaryl]

Like always good stuff my man! keep them coming. I will be a master Tech before the summer"s out!

[DrZarkloff]

@merodaryl Cool! That's a lot to learn.

[apnaconstruction]

so how many lbs r22 i need to put in 3 ton unit

there is any calculator for that ??

how to calculated freon to put in unit ??

Dr z

thanks

[DrZarkloff]

@apnaconstruction You should put about 2 pounds of refrigerant per ton of air before starting the system for a weigh-in charge or for superheat and subcooling charge.

[blissJesus1]

dr. Z, I am trying to wrap my mind around friction rates, with length of duct by size; for example' A duct is 40 ft. long, and is 6 in. by 9 in.. The quantity of air to be delivered is 400 cfm. What is the friction rate?. Is there a simple way to understand how to figure this out?, and thank you Dr. Z, your the best HVAC/ YOU TUBER.

[DrZarkloff]

@blissJesus1 You could get a ductulator from a HVAC parts house. Just line up your duct size and cfms to get your friction rate. Friction rate is the amount of drag there is on the air flow.

[whyms1]

how do you calculate the amount of refreg gas to put in a system when rechargeing a hvac system

[DrZarkloff]

@whyms1 the refrigerant charge should always be weighed in with packaged systems. Split systems, with the exception of mini split systems, should be charged by superheat or subcooling.

[whyms1]

@DrZarkloff Does the lenght of the line set effect the amount of gas needed to charge a HVAC system Mike Key West, Fl

[djslay34982]

@whyms1 Yep, Usually you can call the manufacturer and ask how much more refrigerant needs to be added per foot of line set.

[yantur52]

You r the best teacher that I see at this time for real thanks to be here.

[DrZarkloff]

@yantur52 Thanks for watching.

[uchemp]

Here are you from?

[DrZarkloff]

@uchemp I live in High Springs, Florida. I was born in Ohio, raised in Arizona and I've lived in Florida nearly all of my adult life.

[death2opposeme]

say Dr. Z you got anything on zone controls?? or 24v communication boards?? or anything like water towers, chillers, boilers, larger package units with rtrm or upc boards in them. ice machines or drink machines?? i do a little of everything. im lucky starting out on the large equip.

[Tranic85]

zone control systems just flat out dont work. they cant keep up in the summer time.

[DrZarkloff]

@death2opposeme All of the zoning controls that I work on are by computer. Alerton is the most common.

[death2opposeme]

@DrZarkloff ill have to see how its done at a few of our customer's buildings... and come back to you on that. there rough. even our experienced tech who can handle em, hates them to hell and back lol.

[albookham]

Hi dr zarloff just want to say you are doing a wonderful job in helping us young A/C techicians. im a A/C and refrigeration technician from Jamaica. a good topic would be types of compressor and how they work. respect, nuff luv seeen yeh man

[playone4me]

DR Z can you figure the btu.s by measureing current readings ? If so can you make a short video to prove the point thanks very much for your videos Pete from Newyork city electrician

[DrZarkloff]

I'm sure that it can be done. I all depends on the type of compressor. Be it scroll, reciprocating, centrifugal, screw, rotary, etc.

[rhgoodwin5zvm]

Just a question... I thought 1 ton = 12,000 BTU/hr. BTU is unit of energy, where BTU/hr is a unit of power? What am i doing wrong?

[DrZarkloff]

1 ton = 12,000 BTU. BTU/HR: means British Thermal Units per hour. One BTU is the amount of energy that it take to raise one pound of water one degree F.

[rgarciajr4]

thanks a lot man that really helps... i am a pretty ignorant person when it comes to things like this... i learned something thanks to you..

[DrZarkloff]

Thanks for watching.

[vBotics]

should I be concerned with large difference in the A/C and the cooling unit? If so, what's the difference. Can you give me an example of what I would see if the A/C unit was higher (say 2.5 ton) than cooling unit (say 2 ton). Then if the reverse was true.

[DrZarkloff]

You wouldn't be able to get the correct superheat in any case. If the condensing unit were undersize, the evaporator would freeze. If it were oversize, the condensing unit would stack refrigerant.

[jkuang8]

Dr. Z, I have under some units are easier. But RUUD unit is one of the problem I didn't understand. Can you explaint that?

thank you

[DrZarkloff]

Some manufacturers use model numbers that have a different nomenclature. That's when you're stuck having to get someone at the parts store look it up for you.

[jkuang8]

Thank you, I found out the RUUD unit(UAK037) is a 3 ton unit.

[diymania]

Whats w this Ton stuff ? I thought a Ton was 1000 kilos :-/

[DrZarkloff]

One ton equals 12,000 btu.

[jahweh99]

can this apply then to being able to determine capacity of a/c by the btuh of a furnace? so if you want to estimate cooling loads by the required total heating load?

[grego10r]

great vid man

[DrZarkloff]

Thnaks

[Epicx1984]

Can you make a video about sizing the cfm of the furnace to handle the exsisting system for retrofits. Transfering ductwork dimensions to cfm capacity.

I'd also love to see a video about the proper way to read a ductulator.

Thanks in advance

[waters65]

was wonderinf if you might have a sec to help troubleshoot, I have a customer carrier condesing unit fan on top for some reason fan is blowing downward i reversed fan motor doesnt blow at all i flipped blade and tried both ways only blows downward should blow upward right? ty for any help

[DrZarkloff]

Yes, the fan should blow upward. It's one of those things that I'd be able to help if I were there.

[waters65]

customer said hasnt worked right in years if it had a ccw blade and needed a cc blade would that be the prob ya think, maybe someone put wrong blade on it?

[DrZarkloff]

I'd say that if you got the opposite blade rotation that you already have then that should do the trick.

[CarlLewenski]

Don't forget that by posting these videos you are giving away trade secrets...

[DrZarkloff]

Yeah right. LOL

[CarlLewenski]

LOL! I just wanted to see what you would say to that! ;)

I graduated 5 months ago. One more week until I join the Union! YES!!

[hvac809]

now that you talking about calculations, HOW OFTEN do you use CFM ( cubic feet per minute) and FPM ( feet per minute) and calculating tonage and btu's in the field?

[DrZarkloff]

Usually when I have to make corrections to duct.

[Hungry2Play]

i just learned all about this yesterday and today... and many people told me i wont be using this in the field once i get a job... is that true?

[SNL0907]

You use cfm and fpm for sizing ductwork , as well as picking the size of the A/C unit needed to condition the space. You can tell how much cfm an A/C unit can produce by it's capacity. 400 cfm = 1 ton, therefore a 5 ton unit will give you 2,000 cfm. (5 x 400), You also calculate your duct size based on recommended velocity (fpm) for different zones.

[anamericanstory]

that's right!!

[hvac809]

great video by the way.

[hvac809]

WAIT A MINUTE. 1 KW is NOT 3.413 btu.

A KILOWATT is one thousand watts.

1 KW = 3,413 btu with a comma.

1 watt = 3.413 btu with a decimol point.

[jessierios1055]

ur a genius

[NeMeSiSxNai]

you wouldn't believe the number of people that didn't know this / great video!

[tazzjr74]

thanks for the fast response dr z

[tazzjr74]

hey dr z how about figuring out the SEER number of a unit?

[DrZarkloff]

Some manufacturers will proudly print the SEER rating on the unit. In many cases, you'll have to write down the model and serial numbers and find out from a parts store or the manufacturer.

[Wecamefromthestars81]

Goodman=crap

[L3G4LIZ3]

amen

[napais]

This it is another good educational/technical video. Thanks Dr.

[jenko701]

Jim help me find out how where to go to learn how to read carrier model numbers. I think they are differnt than what you are showing.

[DrZarkloff]

I'll try to do another videos soon.

[Aussie50]

I know the Mitsubishi MV series window unit in the back of my workshop is 12,000 BTU / 1 ton, but my Fujitsu split is only marked in Kw, not BTU.

I'm just wondering how to convert Kw to ton. the model is N807 (8.1Kw) on the Fujitsu BTW

Great vid though, I didn't know 12,000 BTU was a ton.

[caletcalet]

1 Kw = 3.413 BTU

[Aussie50]

Thx m8

Its just over 2 ton then

[ArtistBlade1972]

@Aussie50 The refrigeration "ton" comes from ice. It takes 144 BTU to melt 1 lb of ice. A ton 2000lbs in the US would absorb 288,000 BTU in melting. The scale is based on it melting in a 24hr period which would be 288,000/24=12,000

So the ton of ice as it melts in one day's time would absorb 12000 BTU per hour

[Darvin1964]

thanks for refresher keep up good work

[V8Jagnut]

good vid. now i know i have a 1 ton a/c in my shed.lol

[DrZarkloff]

That's pretty good for a window unit.

[V8Jagnut]

yer. 15,000 btu. it gets hot hear. i have a 12,000btu in my room.lol

[gasfitter1]

thanks for the info very helpfull,but i had the pleasure of having to work on a unit that had no data plate

[DrZarkloff]

You can do the same thing with the model number on most compressors, too.

[heavyhvac]

good one dr Z thats how we do it in class keep up the good work

[DrZarkloff]

Thanks