HVAC Education, What is a BTU?

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HVAC Education, What is a BTU?

HVAC Education, What is a BTU?

At Ambassador Dearie HVAC, we believe an educated customer is a better customer. We will attempt to explain some of the more common phrases and terms you might hear discussed when asking about heating or cooling products.

Today, we are tackling the basic unit of measurement for HVAC, the BTU.

The British Thermal Unit or BTU is defined as the amount of heat it takes to raise one pound of water by 1 degree Fahrenheit. Ok, but what does a BTU look like? Basically if you took a wooden match and lit it, the heat given off would be equivalent to 1 BTU. So for those avid BBQ’ers, 45,000 BTU’s means you’d have 45,000 wooden matches of heat available to cook your meat and vegetables.

When we design your new homes heating system we need to factor in how much heating and cooling you’ll need to remain comfortable all year long. We perform a heat gain/heat loss calculation based on numbers of windows, floors, size of your home and how air tight the house is. We can even factor in which direction the home is facing to get real accurate. Why is this needed? Fitting the right sized HVAC system to your house is just as important as making sure you have the right size tires on your car. Too small of a system will mean overwork and potential gaps when calling for a particular temperature. Too large a system could mean temperature spikes as the unit comes on and satisfies the temperature too quickly then shuts off. Having “the goldilocks”, or “right-sized” system means better efficiency and comfort for the homeowner.

How does BTU relate to cooling?

When you hear “tons of cooling”, it refers to the size of your AC. It takes 12,000 BTU’s to melt 2000 lbs or 1 ton of ice. So when you hear you need a 1.5 ton unit, you will be getting the equivalent of 18,000 BTU’s or 3,000 lbs of cooling.

1 Ton = 2,000 lbs or 12,000 BTU’s
1.5 Ton = 3,000 lbs or 18,000 BTU’s
2 Ton = 4,000 lbs or 24,000 BTU’s
2.5 Ton = 5,000 lbs or 30,000 BTU’s
3 Ton = 6,000 lbs or 36,000 BTU’s

Model Nomenclature (Now you know)

Furnace and AC manufacturers will incorporate the BTU measurement into their product models. A few examples below include:

Lennox Furnace EL296UH090XV36C

EL= Elite Series
2 = 2 Stage gas valve
96= 96% efficient
UH=Upflow Horizontal (position for installation)
090=90,000 BTU’s Heating
XV= Variable Speed Motor
36= 3 Tons cooling compatible

Goodman AC GSX160241

GSX= Goodman Series
16= 16 Seer
024= 2 Tons or 24,000 BTU’s of cooling

We hope you appreciate this explanation and if you ever have any questions please feel free to submit them via our web site.

Till next time

Ambassador Dearie HVAC Management