Carrier Model Numbers Explained
Partner, Carrier Corporation has determined that this product meets the ENERGY STAR® guidelines for energy efficiency. Model number nomenclature 38EZG 018 Standard 12 SEER Split-System Air Conditioner Nominal Capacity 018 — 18,000 Btuh 042 — 42,000 Btuh 024 — 24,000 Btuh 048 — 48,000 Btuh 030 — 30,000 Btuh 060 — 60,000 Btuh 036.
- POST a QUESTION or READ FAQs about how to find out the cooling capability of an air conditioner or heat pump from translating its data tag, label, or other information.
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Rated cooling capacity of an air conditioner or heat pump:
Here we explain exactly how to estimate the rated cooling capacity of an air conditioning system by examining various data tags and components.
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
RATED COOLING CAPACITY - How to Determine Air Conditioning or Heat Pump Equipment Rated Cooling Capacity
The cooling capacity of an air conditioning system is expressed in BTU's or tons. One ton of coolingcapacity equals 12,000 BTU's/hour of cooling capacity.
[Click to enlarge any image]
'One ton' of cooling capacity, historically, referred to the cooling capacity of a ton of ice.Tons of ice does not explain a key ingredient in the comfort producedby air conditioning systems, dehumidification of indoor air - that is, taking water out of the air.
Cool air can hold less water (in the form of water molecules or gaseous form of H2O) than warm air. Think of the warmer air as havingmore space between the gas molecules for the water molecules to remain suspended.
When we cool the air, we in effect are squeezing thewater molecules out of the air.
When an air conditioner blows warm humid building air across an evaporator coil in the air handler unit, it is not only cooling the air, it's squeezing out some of the water in that air. Both of these effects, cooler air and drier air, increase the comfort for building occupants. Sketch courtesy of Carson Dunlop Associates.
There are several ways to determine the rated cooling capacity of an air conditioning system's equipment:
Air Conditioning Equipment Age and Capacity from Equipment Numbers
Serial number formats vary by range of years over which equipment was manufactured, and mayvary among countries of manufacture for a given company's equipment, for example between theU.S. and Canada for Carrier air conditioning equipment.
Example: a Carrier Compressor/Condenser Serial# 1389E54894 on a compressor unit.
Air conditioning equipment age from serial number for the example above, the equipmentwas made after 1980. The first four digits of the serial number are week and year of manufacture,in this case, week 13 of 1989.
See AIR CONDITIONER BTU CHART for a guide to selecting an air conditioning system with the proper cooling capacity in tons or in BTUs.
Sankat mochan hanuman temple gilroy. Sketch courtesy of Carson Dunlop Associates.
FROM MODEL # - Air conditioning equipment capacity from model number
Example: Carrier A/C Compressor Condenser Model# 38XD12400 (same unit as usedfor the serial number example above), there is variation in how Carrier assigned thesenumbers but typically the numbers indicate either tonnage or MBTUH. This example hasdigits in the 4th and 5th positions (right hand 5 digits), so the rating isin MBTUH for this number and '24' signifies 24 MBTUH or 2 tons of capacity.
Be sure to review our article on how to read the data in
A/C DATA TAGS for a guide to reading the system cooling capacity either directly off of the sticker on the equipment, or for examples ofhow to find them model number which can be de-coded into cooling capacity and other features.
A Reference Guide to Heating and Air Conditioning Equipment model numbers, serial numbers, age, and capacity:at Carson Dunlop's - Technical Reference Guide, publishedby Carson Dunlop Weldon & Associates, Ltd., Toronto, 2006 for a $69.00 book which translates air conditioningequipment model numbers and serial numbers into date of equipment manufacture and rated BTUH capacity.
FROM EQUIPMENT RLA # - Air Conditioning Equipment Capacity from Equipment RLA Numbers
RLA Rule of Thumb: RLA, Rated Load Amps, or in some older texts, mis-named as 'Running Load Amps'is the manufacturer's specified rated current draw when the equipment is operating, excluding thecurrent draw during startup, but when the compressor is under load.
On a single-phase 240V circuit feeding an A/C compressor/condenser unit, the equipment will drawtypically 5 to 6, (7 in some cases) RLA per ton of cooling capacity.
So if the data tag on a compressor shows its RLA rating=21.2 I would rate the system as 21.2/7=3 Tons.
Translating Tons into BTUH, 3tons x 12 MBTUH/ton = 36,000 BTUH estimated Cooling Capacity. Details of this and related calculations are in the 'Guide' book cited above.
COOLING RULES OF THUMB - determining Cooling Capacity Requirements - Rules of Thumb
A home inspection does not involve the calculationsof heat gain necessary to decide if the cooling capacity on a building is adequate, but the inspector is expectedto examine and report on the rated system capacity (such as '36,000 BTUH') and on the presence or absence ofcooling sources in the habitable rooms of the building.
Air conditioning capacity requirement:
A simple rule of thumb for relatively cool climates such as the Northeastern United States: one ton per 400 sq .ft. (Commercial) or one ton per 500 to 1000 sq .ft. (Residential)
Orwe estimate an air conditioning requirement of one ton per 400 to 800 sq .ft. for Space Pak Systems.
Or a 3000 sq .ft. house may require a 5-ton unit. Or count thesupply outlets: 10 outlets @ 100 cfm (estimated) = 1,000 cfm = 2.5 tonsneeded.
Oversized Air Conditioning Systems: Can an air conditioning system have too much capacity?
Carrier Model Numbers Tonnage
Yes. If a system is over sized for a building it may be able to drop the indoor temperature so rapidly that the cooling cycle is too short to permit adequate reduction in the humidity level. Remember that indoor comfort is a function of both temperature and relative humidity.
Also, since an oversized air conditioning system will be cycling on andoff more frequently, not only is the building actually less comfortable (temperatures are swinging up and downunnecessarily quickly and frequently) but it may also be harder on the equipment, thus shortening its life.
Turning electric motors on and off is hard on them.
If the 'on cycle' of the A/C system seems unusually brief, or if the indoorhumidity is not dropping this question merits further investigation. Sketch courtesy of Carson Dunlop Associates.
Do not buy an air conditioner that has more tons or BTUs of capacity than you actually need.
How to Determine BTUs or Tons of Cooling Capacity of an Air Conditioner from its Data Tags
In addtion to reading the present article (here) see
COOLING COIL or EVAPORATOR COIL
or determine rated cooling capacity
FROM MODEL # - how to determine the BTU capacity or Tons of cooling capacity of an air conditioner from model number
FROM EQUIPMENT RLA # - how to determine the BTU capacity or Tons of cooling capacity of an air conditioner from the RLA number.
How Big Should My Air Conditioner Be in BTUs or Tons?
In addition to reviewing
our COOLING RULES OF THUMB shown above,
see AIR CONDITIONER BTU CHART for a guide to selecting an air conditioning system with the proper cooling capacity in tons or in BTUs.
What Temperature Should an Air Conditioner Be Able to Maintain
Reader Question: 8/27/2014 Anonymous said: hat temperature should my new central A/C be able to hold
Regardless of all the sizing, energy usage and environmental considerations, what temperature should my new central A/C be able to hold at the hottest time of day? It seems like this should by irrespective of any particular climate, just need more capacity the hotter it can become.
Reply:
I'm not sure I agree that the performance of air conditioning systems - the ability to hold a specific temperature at the hottest time of the day - is nor can be independent of the system design.
For example, if we have a poorly insulated building, a building with high heat gains, a building where people regularly leave windows and doors open or come in and out constantly, it could be misleading and specious to only blame the air conditioning system for complaints that the building interior is too arm.
Wouldn't we first close open windows and doors, before installing a new, larger cooling system?
However you are quite right to ask how we should measure whether an AC system is performing as it should.
Some helpful references that answer that question are at
ANSI/AHRI Standard 210/240 with Addenda 1 and 2 (formerly ARI Standard 210/240) titled in more detail '2008 Standard for Performance Rating of Unitary Air - Conditioning & Air-Source Heat Pump Equipmet' (available online from AHRI and ANSI)
You might also want to refer to TSI's 'Hvac Assessment Handbook A practical guide to performance Measurements in mechanical heating, Ventilating, and air conditioning systems' available from tsi [dot] com
In Australia and New Zealand or the South Pacific we refer readers to 'Performance Standards Of Hvac Equipment (HVAC Equipment Performance Consultancy)' available from the Australian government abcb [dot] gov [dot] au
Carrier Hvac Model Numbers Explained
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Continue reading at SEER RATINGS & OTHER DEFINITIONS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
Or see RATED COOLING CAPACITY FAQs - questions & answers posted originally at this page.
AIR CONDITIONER TEMPERATURE MEASUREMENT for a discussion of what temperatures to expect at different points in the air conditioning system.
AIR CONDITIONER BTU CHART - table of BTU requirements by cooling area size & other parameters
Also see LOST COOLING CAPACITY for diagnosis of poor air conditioner performance, and see This website answers all questions about air conditioning and heat pump systems.
Suggested citation for this web page
RATED COOLING CAPACITY at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.
INDEX to RELATED ARTICLES: ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS
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Technical Reviewers & References
- ..
- Thanks to Scott at SJM Inspect for suggesting this EPA document and for technical editing remarks regarding our air conditioning website,SJM Inspection Service LLC, serves the entire state of CT, sjminspect.com 203-543-0447 or 203-877-4774 5/16/07
- Modern Refrigeration and Air Conditioning, A. D. Althouse, C.H. Turnquist, A. Bracciano, Goodheart-Willcox Co., 1982
- Principles of Refrigeration, R. Warren Marsh, C. Thomas Olivo, Delmar Publishers, 1979
- 'Air Conditioning & Refrigeration I & II', BOCES Education, Warren Hilliard (instructor), Poughkeepsie, New York, May - July 1982, [classroom notes from air conditioning and refrigeration maintenance and repair course attended by the website author]
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
- Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
- Complete List of Air Conditioning & Heat Pump Design, Inspection, Repair Books at the InspectAPedia Bookstore.
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- The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors.
Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page 'Promo/Redemption' space. - TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates
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- The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors.
- The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.
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I'm new to iPhones,if a phone is stated to be network unlocked,carrier unlocked and factory unlocked will it be able to be used with any carrier? The iPhone is a iPhone 5 Thank you. Loritiana123
1 Answer
Yes, but not Necessarily any carrier.
Network unlocked, carrier unlocked, factory unlocked all essentially mean that the phone can be used on any carrier that model is designed to work. There is different meaning factory unlocked suggests the phone was never carrier locked and bought directly from Apple for the full retail price. Carrier unlocked suggests that it was once locked to a carrier and has now been unlocked. Network unlock could mean either.
Determine the exact model number of the phone. For an iPhone 5 it's likely A1428 (GSM) or A1429 (has both CDMA and GSM models).
Consult this table on Apples website to see which models work on which carriers by country. (You will need to scroll down considerably to reach the iPhone 5 section.)
The model number is printed on the back cover of the phone. Source Apple Support Article HT201296.
FWIW, if you're considering purchasing this phone used you should request proof that it is carrier unlocked.
You should also use Apples Activation Lock tool before buying to ensure that the findMyiPhone is turned off. If the activation lock shows on the phone will be of no use to you, until the original owner releases it. This is different than the carrier locking.