The split unit doesn't cool, the room stays warm, the bill went up. It almost always starts with the BTU.
A free checklist, the E-Nogueira site's BTU calculator (in Portuguese) and a 3-hour course so you can choose the right air conditioner without wasting money.
The unit isn't the problem. The math is.
An undersized split unit runs flat out all day and never reaches the set temperature. An oversized one keeps switching on and off, doesn't remove the humidity and costs more to buy. Either way, the electricity bill comes in higher than it should.
The path is the same one E-Nogueira follows before selling or installing: measure the room, calculate, check what the calculator can't see and only then choose.
Who it's for
It's for you if:
- you're buying an air conditioner for a home or business and want to get the size right;
- you used the site's BTU calculator and want to understand the number;
- you're a helper or a beginner in refrigeration and want the basics before installing.
It's not for you if:
- you want to learn to install split units: that's course CL3 (level 2);
- you want the course to recommend a brand or model: the Academy doesn't name brands or suppliers;
- you're looking for certification to handle refrigerant.
The path, from problem to Pro
Four steps: the checklist by email, what you can do before calling someone, the entry course and Academy Pro.
Free checklist
The BTU calculator and what it can't see: 9 items to measure and decide.
Site tool
The site's BTU calculator, with electrical and consumption estimates. Run a business? Also use the PMOC generator (in Portuguese; PMOC is the Brazilian HVAC maintenance plan required by law for commercial buildings).
Entry course
CL1 BTU in practice: 6 lessons, 3 hours, sold as a single course.
Academy Pro
All 23 courses and the private community for your field, with a monthly or yearly subscription.
Before you buy: use the BTU calculator
The BTU calculator is free to use on the E-Nogueira site. You enter the area, sun exposure, people and appliances, and it suggests the capacity, current, cable, circuit breaker and monthly consumption to take to your electrician.
Open the BTU calculator → · PMOC generator →
What it doesn't do: it can't see a high ceiling, afternoon sun on a glass wall or peak occupancy. Lesson 4 of CL1 shows when a room needs a full calculation.
Entry course: BTU in practice
BTU in practice: sizing the air conditioner for a room (CL1) · 6 short lessons · 3 hours · level 1 (fundamentals) · sold as a single course or included in Academy Pro.
By the end, you'll be able to:
- explain how the refrigeration cycle removes heat from a room;
- convert BTU/h, kW and TR (tons of refrigeration) and read capacity and consumption on the label;
- calculate the heat load of a room with the simplified method;
- use the site's BTU calculator and recognize when a room needs a full calculation;
- choose between inverter and conventional, and between wall-mounted, cassette and floor-ceiling units;
- spot undersizing and oversizing and know what to ask the installer for in writing.
Each lesson has a worked example, a field checklist, review questions and a task in your own space.
A single course is yours forever; the community and the app are part of Academy Pro.
After CL1
- CL2 Preventive maintenance of split units: cleaning, measurements and what builds loyalty (level 1)
- CL3 Split installed right: drilling, piping, vacuum and charge (level 2)
- CL4 Dedicated electrical work for HVAC: circuit, protection, drains and finishing (level 2)
- CL5 PMOC for small businesses: from the law to the recurring contract, with the site's generator (level 2)
- CL6 Split diagnosis and repair: no cooling, freezing up, leaking — refrigerants, environment and good practice (level 3)
Together with the entry course and TR1 (Quotes, proposals and client relationships), they make up the Air conditioning: from BTU to repair track. All included in Academy Pro.
What backs up what you'll read here
- Since 2014 E-Nogueira has been doing electrical, HVAC, solar energy and electronic security work in homes, businesses and small farms around São João da Boa Vista, São Paulo, Brazil.
- 33 Google reviews on E-Nogueira's Business Profile. They come from service customers, not students: the Academy is new and doesn't have student testimonials yet. When it does, they'll appear here.
- Real job-site situations as the starting point of every lesson: the split unit too small for a room with afternoon sun, the indoor unit that freezes up from lack of maintenance, the business with no PMOC.
- Free tools on the site (in Portuguese): BTU calculator, PMOC generator, electrical design tool and solar sizing tool. Open to anyone, no Academy sign-up needed.
Who writes the courses
Marcelo Nogueira Souza — electrical technician · HVAC and refrigeration technician · E-Nogueira, São João da Boa Vista, São Paulo, Brazil, since 2014.
Every Academy course is written by him from what he does on the job, with each standard cited and explained the first time it appears. The technical basis is Brazilian (ABNT standards, laws and regulations); the principles apply in any country, and the text points out when a rule is local.
The certificate is an E-Nogueira Academy completion certificate: it records course hours and content. It's a non-degree course, not recognized by the MEC (Brazil's Ministry of Education), and it doesn't replace professional licensing.
Academy Pro: the whole Academy, for subscribers only
All 23 courses, the private community with a room for each field, the Pro Room with exclusive content, live sessions and events as they're scheduled, and the E-Nogueira Academy app. Monthly or yearly subscription, no lock-in. To subscribe, open mamaofy.com/m/enogueira/plans: if you don't have an account yet, sign up and continue to choose your plan.
Academy Pro
E-Nogueira
Every E-Nogueira Academy course in one subscription. What it includes: - All 23 Academy courses (electrical, air conditioning, solar energy...
Frequently asked questions
Clear your doubts about our courses
Isn't the BTU calculator enough?
Will I learn to install a split unit?
I run a business. Do I need a PMOC?
Is there a certificate?
How do I get the checklist?
Did not find what you were looking for?
Contact us through the form below and we will respond as soon as possible.
Get the BTU checklist
Leave your name and email and get the PDF “The BTU calculator and what it can't see”: the field checklist from lesson 4 of the course BTU in practice (CL1). It has 9 items to print and take with you: measure with a tape, note the ceiling height, check which way the windows face, count the people at peak times, write down the calculator's result and decide whether the room needs a full calculation.
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Contact E-Nogueira
One WhatsApp number: +55 (11) 92053-5225. E-Nogueira Academy · São João da Boa Vista, São Paulo, Brazil · since 2014. Courses issue a completion certificate; it doesn't replace professional licensing.