How To Look At A House

site-built, mobile/manufactured and modular homes

## How do I tell the size in tons of my WeatherKing air conditioner or heat pump?

Monday, December 16, 2019

You can determine the “nominal” size of your HVAC system by examining the model number on the data plate at the side of the condenser (outdoor unit). Just like the nominal size of lumber or an air conditioning filter, the exact cooling capacity may be a little more or less than the nominal rating, but it’s close.

For WeatherKing, you should look for the two numbers in the second cluster of digits of the model number, which will be divisible by 6 or 12, and represents the nominal BTU of the system in thousands. A ton of air conditioning equals 12,000 BTU, and 24 divided by 12 equals 2, so the data plate below indicates the system is 2 tons.

WeatherKing is one of the few brands that varies slightly from this format sometimes. For example, the data plate shown below is for a nominal 3 ton unit, although the number is 37 instead of 36.

Here’s a rundown of the range you will encounter: 18 = 1.5 tons, 24 = 2 tons, 30 - 2.5 tons, 36 = 3 tons, 42 = 3.5 tons, 48 = 4 tons, and 60 = 5 tons.

If you are unsure whether you have found the right two numbers, you can double-check it by looking for the “RLA” rating on the data plate. RLA is an acronym for Rated Load Amperage, and is what the maximum amperage should be when the condenser up and running. If you divide the RLA by 6 for older units and 5 or 6 for newer units, you should get a number that approximates (not exactly) the tonnage of the system. Make sure you use RLA and not LRA, Locked Rotor Amperage, which is the surge of amps necessary to overcome inertia and start the system. It averages around five times the RLA.
To determine the age of your WeatherkIng system go to our blog post How do I determine the age of a WeatherKing air conditoner, heat pump, or furnace from the serial number? For the age of another brand or manufacturer, go to our blog post How do I determine the age of my air conditioner? and, for other key specs, see one of these other blog posts:

How can I find out the SEER of my air conditioner?

• • • • • • • • • • • • • • • • • • • • •
Field Guide for Home Inspectors, a quick reference for finding the age of 154 brands of HVAC systems, water heaters, and electrical panels, plus 210 code standards for site-built and manufactured homes, and the life expectancy rating of 195 home components. Available at amazon.com for \$19.95.
• • • • • • • • • • • • • • • • • • • • • •

My air conditioner won't turn on. What's wrong?

How can I find out the size of my air conditioner?

Where is the air filter for my central air conditioner and furnace? I can’t find it?

Does an old air conditioner use more electricity as it ages?

What is wrong with an air conditioner when the air flow out of the vents is low?

Why has the thermostat screen gone blank?

Why does it take so long to cool a house when an air conditioner has been off for a while?

Why is my air conditioner not cooling enough?

What are the most common problems with wall/window air conditioners?

Visit our HEATING AND AIR CONDITIONING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

Water Heaters

Water Heater Age

"What Are The

Signs Of..."

Septic Tank Systems

Structure and Rooms

Plumbing Pipes

Termites, Wood Rot

& Pests

Sinkholes

Stairs

When It First

Became Code

Park Model Homes

Site

Shingle Roofs

Safety

Stucco

Remodeling

Wind Mitigation

Roof and Attic

"Does A Home

Inspector...?"

Pool and Spa

"What Is The Difference Between..."

Brick

Plumbing

Concrete and

Concrete Block

Metal Roofs

Foundations

Modular Homes

Rain Gutters

Condominiums

Older and

Historic Houses

Crawl Spaces

Mobile-Manufactured Homes

Building Permits

Life Expectancy

Clay Soil

Insurance

Floors

Insulation

Toilets

Exterior Walls

& Structures

Generators

Common Problems

HUD-Code for

Mobile Homes

Garages and Carports

Flat (Low Slope) Roofs

Electrical Panels

Sprinkler Systems

Electrical Receptacle Outlets

4-Point Inspections

Hurricane Resistance

Home Inspection

Heating and Air Conditioning

Building Codes

Fireplaces and Chimneys

Inspector Licensing

& Standards

Energy Efficiency

Washers and Dryers

Electrical

Kitchens

Doors and Windows

Cracks

Electrical Wiring

Click Below

to Collections

of Blog Posts

by Subject

Plumbing Drains

and Traps

Appliances

Smoke & CO Alarms

Aging in Place

Top 5 results given instantly.

Click on magnifying glass

for all search results.

Bathrooms

Lighting

AFCI, CAFCI,

DFCI, & GFCI

Sinks

Air Conditioner & Furnace Age/Size

Attics

Electrical Switches

Siding

Search

This

Site

Water Intrusion

Electrical - Old

and Obsolete

Foundation Certifications

Tiny Houses