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Key Facts: BTS FED Exam

Level 5 (Bac+2)

RNCP and EQF national qualification level

France compétences RNCP38361

10/20

Overall passing weighted average

Règlement général du BTS

Total examination coefficients across the nine units

Arrêté du 21 décembre 2016, annexe II c

120 ECTS

European academic credits awarded

Arrêté du 26 février 2014

3 Options

Specialization tracks (GCF, FCA, DBC)

Arrêté du 26 février 2014

31-12-2028

RNCP registration expiry date

France compétences RNCP38361

BTS FED is a French national level 5 qualification (Bac+2, 120 ECTS) certified by the Ministry of Higher Education and examined by the académies. Under the arrêté du 26 février 2014 modifié par arrêté du 27 octobre 2023, the examination comprises six compulsory units totalling 28 coefficients: written technical papers including E4.1 Analyse et définition (coef 4, 4 h) and E4.2 Physique-Chimie (coef 2, 2 h), practical commissioning tests (E5 coef 5), a major project defence (E6 coef 8), and general subjects. Candidates require an overall weighted average of at least 10/20 and register free of examination fees via Cyclades. The official examination is in French; OpenExamPrep provides a 100-question English-language MCQ study adaptation covering thermodynamics, HVAC, RE2020, smart building automation, and fluid networks.

Sample BTS FED Practice Questions

Try these sample questions to review concepts for the BTS FED exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1In a vapor-compression refrigeration cycle plotted on a Mollier pressure-enthalpy (log p-h) diagram, subcooling of the liquid refrigerant before the expansion valve directly causes which of the following thermodynamic effects?

A.An increase in compressor discharge temperature and superheat

B.A decrease in the condensing pressure and condensation temperature

C.An increase in specific refrigerating effect (kJ/kg) without increasing compressor work per kg

D.An increase in compressor power consumption proportional to the degree of subcooling

Explanation: Subcooling (sous-refroidissement) cools the liquid refrigerant below its bubble-point temperature at high pressure before it enters the expansion valve. On the log p-h diagram, this shifts the expansion line to the left, resulting in lower inlet enthalpy to the evaporator (h_4 < h_4,sat). Because the evaporator inlet enthalpy is reduced while the evaporator outlet enthalpy remains constant, the specific refrigerating effect Δh_0 = h_1 - h_4 increases without changing compressor work w = h_2 - h_1, thereby increasing the cycle COP.

2What is the primary operational purpose of ensuring a minimum useful superheat (surchauffe fonctionnelle) of 5 K to 8 K at the evaporator outlet before refrigerant enters the compressor?

A.To prevent liquid refrigerant droplets from entering the compressor and causing hydraulic shock (coup de liquide)

B.To maximize the volumetric efficiency of the compressor by lowering the suction vapor density

C.To reduce the discharge temperature at the condenser inlet

D.To allow the expansion valve bulb to close completely during peak cooling loads

Explanation: Refrigeration compressors are positive-displacement machines designed to compress vapor only. Liquids are virtually incompressible. A minimum useful superheat (5 to 8 K) guarantees that all liquid refrigerant has completely vaporized inside the evaporator, protecting the compressor cylinders, valves, and pistons from mechanical destruction caused by liquid slugging (coup de liquide) and preventing oil foaming in the crankcase.

3A water chiller operates with an evaporator cooling capacity of P_0 = 120 kW and absorbs an electrical power of P_e = 30 kW at the compressor motor. What is the Energy Efficiency Ratio (EER / COP froid) of this refrigeration unit?

A.0.25

B.5.0

C.3.0

D.4.0

Explanation: The Energy Efficiency Ratio for cooling (EER or COP_froid) is the ratio of useful cooling thermal power produced (P_0) to the electrical power consumed (P_e): EER = P_0 / P_e = 120 kW / 30 kW = 4.0.

4A refrigeration compressor draws in vapor at state 1 with enthalpy h_1 = 400 kJ/kg. Under isentropic compression, the discharge enthalpy is h_2s = 440 kJ/kg. The actual discharge enthalpy measured at state 2 is h_2 = 450 kJ/kg. What is the isentropic efficiency (rendement isentropique η_is) of this compressor?

A.0.88 (88%)

B.0.80 (80%)

C.1.25 (125%)

D.0.75 (75%)

Explanation: The compressor isentropic efficiency is defined as the ratio of the theoretical isentropic work to the actual work done on the refrigerant: η_is = (h_2s - h_1) / (h_2 - h_1) = (440 - 400) / (450 - 400) = 40 / 50 = 0.80 (or 80%).

5In psychrometric calculations for an air-conditioned room, the Sensible Heat Ratio (SHR / Facteur de Chaleur Sensible FCS) is defined by which formula?

A.SHR = Q_s / (Q_s + Q_l)

B.SHR = Q_l / Q_s

C.SHR = (Q_s + Q_l) / Q_s

D.SHR = Q_s / Q_l

Explanation: The Sensible Heat Ratio (SHR / FCS) is the fraction of the total room thermal cooling load that is sensible heat: SHR = Q_s / Q_t = Q_s / (Q_s + Q_l), where Q_s is the sensible heat load and Q_l is the latent heat load. It determines the slope of the room condition line (droite de soufflage) on the psychrometric chart.

6When moist air passes through a hot water heating coil without any injection of water or steam, how does the state point move on a Carrier psychrometric chart?

A.Vertically upwards (absolute humidity increases at constant dry bulb temperature)

B.Along a constant wet bulb temperature line downwards to the right

C.Horizontally to the right (dry bulb temperature increases at constant absolute humidity ratio)

D.Horizontally to the left (dry bulb temperature decreases at constant enthalpy)

Explanation: Sensible heating of air adds thermal energy without adding or removing moisture. Therefore, the absolute humidity ratio w (g of water per kg of dry air) remains strictly constant, moving horizontally to the right on the Carrier psychrometric chart. As dry bulb temperature increases at constant moisture content, relative humidity decreases.

7An air stream at 26°C dry bulb enters a cooling coil with an apparatus dew point (ADP / température de surface de batterie) of 10°C. The air leaves the coil at 14°C dry bulb. What is the coil bypass factor (Facteur de by-pass BF)?

A.0.75

B.0.25

C.0.15

D.0.40

Explanation: The bypass factor (BF) characterizes the fraction of air that passes through the coil fin gaps without contacting the cold surface: BF = (T_leaving - T_ADP) / (T_entering - T_ADP) = (14 - 10) / (26 - 10) = 4 / 16 = 0.25 (or 25%).

8In an air handling unit mixing box, 2,000 m³/h of outdoor fresh air at 0°C is mixed with 6,000 m³/h of return air at 20°C. Assuming constant air density, what is the resulting dry bulb temperature of the mixed air stream?

A.10°C

B.12.5°C

C.17.5°C

D.15°C

Explanation: The total mixed volumetric flow rate is 2,000 + 6,000 = 8,000 m³/h. By thermal energy conservation (with constant air properties): T_m = (V_ext · T_ext + V_rec · T_rec) / V_tot = (2,000 × 0 + 6,000 × 20) / 8,000 = 120,000 / 8,000 = 15°C.

9On a Carrier psychrometric chart, how does adiabatic water spray humidification (humidification par laveur d'air adiabatique) differ from dry steam injection humidification (humidification à vapeur sèche)?

A.Adiabatic humidification increases dry bulb temperature while steam humidification cools the air

B.Both processes follow exactly the same line of constant relative humidity

C.Adiabatic humidification follows a line of approximately constant wet bulb temperature/enthalpy while dry bulb drops; steam humidification is nearly isothermal with dry bulb temperature remaining constant

D.Adiabatic humidification increases air enthalpy significantly whereas steam humidification keeps enthalpy constant

Explanation: In adiabatic spray humidification, the water droplets evaporate by extracting latent heat from the air itself; hence, dry bulb temperature falls while enthalpy and wet bulb temperature remain nearly constant (h ≈ const). In contrast, dry steam injection introduces water that is already in vapor form at 100°C, so the latent heat is supplied externally by the boiler; the air absorbs the moisture with virtually no sensible cooling, moving almost vertically upwards at nearly constant dry bulb temperature (T_db ≈ const).

10In reciprocating refrigeration compressors, what is the primary consequence of an increased compression ratio τ = P_k / P_0 on the volumetric efficiency (rendement volumétrique η_v)?

A.Volumetric efficiency decreases because high-pressure gas trapped in the cylinder clearance volume (espace mort) re-expands over a larger stroke fraction before the suction valve can open

B.Volumetric efficiency increases because higher pressure forces the suction valves to open earlier

C.Volumetric efficiency remains constant because cylinder displacement is fixed by the mechanical crank stroke

D.Volumetric efficiency drops to zero whenever the condensing pressure exceeds 10 bar

Explanation: At the top dead center (TDC) of a piston stroke, clearance volume (espace mort) remains filled with high-pressure discharge gas at P_k. During the intake stroke, this trapped gas must re-expand down to the suction pressure P_0 before the suction reed valves can open. As the compression ratio τ = P_k / P_0 increases, this re-expansion occupies a greater proportion of the piston stroke: η_v = 1 - c [ (P_k/P_0)^1/γ - 1 ], drastically reducing effective volumetric efficiency and refrigerant mass flow rate.

About the BTS FED Exam

The BTS FED is France's premier two-year higher technical qualification (Bac+2, RNCP level 5, 120 ECTS) in HVAC engineering, refrigeration, energy efficiency, and smart building management. Created by the arrêté du 26 février 2014 and updated by the arrêté du 27 octobre 2023, the diploma trains engineering technicians across three specialized options: Option A Génie climatique et fluidique, Option B Froid et conditionnement d'air, and Option C Domotique et bâtiments communicants. The curriculum covers thermodynamic refrigeration cycles, psychrometrics, hydronic and air distribution sizing, building thermal modeling under the RE2020 environmental regulation, building automation protocols (KNX, BACnet, Modbus), and European F-Gas compliance. This OpenExamPrep bank provides an English-language multiple-choice study adaptation covering the shared and option-specific core engineering competencies.

Exam sponsor: Ministère de l'Enseignement supérieur et de la Recherche (certifier); examination organised by the académies. The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Six épreuves covering nine units totalling 28 coefficients, defined by the arrêté du 26 février 2014 (NOR ESRS1403536A, JORF n°0078 du 2 avril 2014), whose règlement d'examen was replaced by the arrêté du 21 décembre 2016 (NOR MENS1636524A, from the 2017 session) and whose unit-exemption rules were amended by the arrêté du 27 octobre 2023 (NOR ESRS2325954A), across three options (A: Génie climatique et fluidique, B: Froid et conditionnement d'air, C: Domotique et bâtiments communicants): E1 Culture générale et expression (U1, coef 4, written 4 h), E2 Anglais (U2, coef 2), E3 Mathématiques et Physique-Chimie (U31 Mathématiques, coef 2, written 2 h; U32 Physique-Chimie, coef 1, written 2 h), E4 Étude des systèmes (U41 Analyse et définition d'un système, coef 4, written 4 h; U42 Physique-chimie associées au système, coef 2, written 2 h), E5 Intervention sur les systèmes (U5, coef 5; CCF, or ponctuelle oral 50 min for individual candidates), and E6 Épreuve professionnelle de synthèse (U61 Conduite de projet, coef 5, oral 50 min; U62 Rapport d'activités en milieu professionnel, coef 3, oral 30 min). An optional modern language unit is available.

Time Limit

About 16 hours of written papers and oral assessment for candidates sitting all units in ponctuelle form

Passing Score

10/20 overall weighted average across all units

Exam / Certification Fees

No examination registration fee is published by the académies; registration is made through the national Cyclades portal. Preparation and tuition costs are separate.

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Official sources

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

25 of 100 questions

Applied Thermodynamics & Psychrometrics

Thermodynamic cycles, vapor-compression refrigeration on the log p-h diagram, heat pump COP, Carrier psychrometric chart calculations, sensible and latent air handling processes

25 of 100 questions

HVAC & Hydronic Systems Design

Heating and cooling load sizing, hydronic pipe sizing, pump head loss and pump curve selection, Air Handling Units (CTA), dual-duct and VAV systems, and air-to-water heat pumps

20 of 100 questions

Building Energy Regulations & Thermal Performance

RE2020 environmental regulation, Bbio and Cep thresholds, envelope U-values, linear thermal bridges, solar heat gain coefficients, and airtightness metrics

15 of 100 questions

Building Automation, Smart Control & Protocols

Building Management Systems (BMS / GTB), open protocols (KNX, BACnet, Modbus, DALI), closed-loop HVAC PID regulation, control valve authority, and sensor integration

15 of 100 questions

Fluid Networks, Water Distribution & Environmental Compliance

Domestic hot water (ECS) sizing, anti-legionella temperature regimes, backflow protection, solar thermal systems, EU F-Gas regulation on refrigerants, low-GWP alternatives, and EN 378 safety

Preparing for the BTS FED Exam

What You Need to Know

Passing score: 10/20 overall weighted average across all units
Assessment: Six épreuves covering nine units totalling 28 coefficients, defined by the arrêté du 26 février 2014 (NOR ESRS1403536A, JORF n°0078 du 2 avril 2014), whose règlement d'examen was replaced by the arrêté du 21 décembre 2016 (NOR MENS1636524A, from the 2017 session) and whose unit-exemption rules were amended by the arrêté du 27 octobre 2023 (NOR ESRS2325954A), across three options (A: Génie climatique et fluidique, B: Froid et conditionnement d'air, C: Domotique et bâtiments communicants): E1 Culture générale et expression (U1, coef 4, written 4 h), E2 Anglais (U2, coef 2), E3 Mathématiques et Physique-Chimie (U31 Mathématiques, coef 2, written 2 h; U32 Physique-Chimie, coef 1, written 2 h), E4 Étude des systèmes (U41 Analyse et définition d'un système, coef 4, written 4 h; U42 Physique-chimie associées au système, coef 2, written 2 h), E5 Intervention sur les systèmes (U5, coef 5; CCF, or ponctuelle oral 50 min for individual candidates), and E6 Épreuve professionnelle de synthèse (U61 Conduite de projet, coef 5, oral 50 min; U62 Rapport d'activités en milieu professionnel, coef 3, oral 30 min). An optional modern language unit is available.
Time limit: About 16 hours of written papers and oral assessment for candidates sitting all units in ponctuelle form
Exam / certification fees: No examination registration fee is published by the académies; registration is made through the national Cyclades portal. Preparation and tuition costs are separate. Official sources

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BTS FED: Suggested Study Strategy

1Master refrigeration cycle calculations on the pressure-enthalpy (log p-h) diagram: calculate compressor work w = h2 - h1, condenser heat rejection qc = h2 - h3, refrigerating effect q0 = h1 - h4, and Coefficient of Performance COP = q0 / w

2Practice reading the Carrier psychrometric chart: determine dry-bulb temperature, relative humidity, specific humidity (g/kg dry air), and enthalpy (kJ/kg) for air heating, cooling, mixing, and humidification

3Understand hydronic network balancing and pump selection: apply the Darcy-Weisbach head loss equation and pump affinity laws (flow proportional to speed, head proportional to speed squared)

4Review French RE2020 indicators: understand the difference between the bioclimatic need indicator (Bbio), primary energy consumption (Cep), and greenhouse gas emissions (Ic_energie / Ic_construction)

5Memorize sanitary water regulations for Legionella pneumophila prevention: ensure storage temperature is kept at or above 60°C and distribution temperature is at least 50°C at every point in looped networks

Frequently Asked Questions

What is the BTS FED qualification in France?

The Brevet de Technicien Supérieur (BTS) Fluides, Énergies, Domotique (FED) is a French national higher technical diploma at level 5 of the RNCP (Bac+2, 120 ECTS). It prepares technical specialists to design, install, commission, optimize, and maintain heating, ventilation, air conditioning (HVAC), industrial refrigeration, fluid networks, and smart home/building automation systems.

What are the three specialized options of the BTS FED?

The BTS FED offers three distinct options: Option A Génie climatique et fluidique (GCF, focusing on heating, ventilation, hydronics, and sanitary networks), Option B Froid et conditionnement d'air (FCA, focusing on commercial/industrial refrigeration systems and air conditioning), and Option C Domotique et bâtiments communicants (DBC, focusing on building automation, IoT, BMS/GTB systems, and connected energy management).

How is the BTS FED examination structured?

Under the arrêté du 26 février 2014 modifié par arrêté du 27 octobre 2023, the examination comprises six compulsory units totalling 28 coefficients: E1 Culture générale et expression (coef 4, written 4 h), E2 Anglais (coef 2, oral), E3 Mathématiques et physique-chimie (coef 3: Maths coef 2, Physique-chimie coef 1), E4 Étude des systèmes (coef 6: U41 Analyse et définition coef 4, written 4 h; U42 Physique-chimie coef 2, written 2 h), E5 Intervention sur les systèmes (coef 5, practical), and E6 Épreuve professionnelle de synthèse (coef 8: U61 Conduite de projet coef 5, U62 Rapport d'activités coef 3).

What is the passing score for BTS FED?

Candidates must achieve an overall weighted average of at least 10/20 across all compulsory examination units. There is no minimum eliminatory score on individual subjects. Marks of 10/20 or higher can be carried forward for five consecutive examination sessions.

How much does it cost to take the BTS FED examination?

Registration for the state examination through the French national Cyclades portal is free of examination fees. Candidates need only provide their personal study materials, technical references, or tuition fees if studying in private establishments.

In what language is the official examination conducted?

The official national examination is delivered in French, with unit E2 evaluating technical English oral communication. OpenExamPrep provides a 100-question English-language multiple-choice adaptation designed to assist bilingual technicians and international learners preparing for the technical and regulatory subjects.

What practical training or internship is required for BTS FED?

Candidates in the school track must complete a mandatory industrial internship of at least 8 to 10 weeks in an HVAC engineering firm, installation contractor, or energy management company. Apprentices satisfy this requirement through their dual-training work contract. The internship activities are defended orally in unit E6.2.

What key environmental and thermal regulations are tested on the BTS FED exam?

The examination tests major French and European energy standards including the RE2020 environmental regulation for new buildings, NF DTU 65 and 68 codes of practice for heating and ventilation installations, European F-Gas regulations governing refrigerants and mandatory leak detection, and standard building automation standards (ISO 16484 for BACnet, EN 50090 for KNX).