PACDim PAC Dimensionnement

A heat pump
that fits the house

PACDim calculates the design heat load to the standard, selects the machine that matches it, and produces the file that proves it

Run a sizing check
Reference case / 120 m² house, zone H1, built 1985 Design heat load, installed capacity
0 16 kW REQUIRED CAPACITY 9.0 kW TYPICALLY INSTALLED 12.0 kW 3.0 kW NOBODY NEEDS DESIGN LOAD 8.0 kW
0%
Calculation accuracy, against 30 in current practice
0s
From complete survey to required capacity
4–0h
Returned to the professional on every project

Oversizing is designed in, not installed in

A French heat pump is routinely specified far above the load the building actually has, because the calculation behind it carries a margin of error near 30% and the professional has to protect himself against a cold house

Why capacity gets added

01 Fear of complaintsThe house must not be cold in January, whatever the number says 45%
02 No reliable toolCalculations done by hand or in a spreadsheet carry a wide margin 35%
03 Demanding standardsRE2020 and RGE QualiPAC ask for expertise that takes years to build 20%

None of these is carelessness, every one is a rational answer to a number nobody trusts, so we removed the cause rather than the behaviour

What the household pays for it
€0

Lost over the fifteen year life of one oversized installation, on the reference case of a 120 m² house

Equipment bought larger than needed€2,500
Energy overconsumption, per year€400
Compressor wear from short cycling2 to 3× faster
Humidity controlDegraded
25 to 50%
Of installed systems are estimated to be oversized
ACHR News, 2023
135,000
Households a year receive a suboptimal system in France
Conservative estimate
€54M
Avoidable national cost every year, in energy alone
Modelled from installation volume
30,000
Additional installers France needs by 2027, the least experienced cohort in the sector
Sector projection

Run the number yourself

Describe a building, and watch the standard produce a capacity, then compare that figure with what usually goes on the wall

120 m²
Construction period
Climate zone
Domestic hot water on the same machine

Indicative calculation on a simplified envelope model, the platform runs the full room by room method of NF EN 12831

Result
9.1kW required
Typically installed12.2 kW
0Capacity scale, 0 to 24 kW24
Walls0
Roof and floor0
Windows0
Ventilation0
Thermal bridges0

Oversizing this building on current practice would cost the household about €8,600 across fifteen years

Six steps, an hour and a half

The same sequence a professional already follows, with the slow parts handed to the machine and the judgement left where it belongs

The workspace, close up

One project file holds the survey, the calculation, the shortlist and the documents, each result carrying the inputs and the engine version that produced it

pacdim.com/workspace/projet-1985-h1
Engine v1.4

Interface preview Prepared building data, shown to make the method legible

Seven modules, one workflow

Six of them follow a single project from the first survey to the signed quotation, the seventh takes the same method into collective buildings

M01

Project workspace

Every study the company has produced, with its calculations, documents and history, searchable and reopenable years later

Address to climate zone, automatic
M02

Building capture

Room by room where the fabric can be surveyed, or from two to three years of energy bills where it cannot, both designed for a tablet without a signal

Offline first
M03

Deperditions calculator

Walls, windows, ventilation and thermal bridges to NF EN 12831, summed into the design load and broken down by component and by room

Result in 30 seconds
M04

Equipment selector

The catalogue filtered to the required capacity, ranked by SCOP for the actual climate zone, checked against budget and subsidy eligibility

Five models, each with a reason
M05

Document generator

Note de dimensionnement, technical data sheet, RGE attestation, subsidy application and branded quotation, produced from the calculation rather than retyped from it

One click
M06

Performance simulator

Savings against the current system over fifteen years, payback including MaPrimeRenov and CEE, and the annual CO2 effect, in a form a household can read

For the kitchen table
M07

Copropriete module

Collective load, hydraulic circuit, acoustic compliance to NF S 31-010 and subsidy calculated per apartment, the part of the product no competitor offers

A different engineering problem

91,000
apartments

Equipped with heat pumps, Ceren and Ministry of Ecological Transition

A collective installation is a different engineering problem, not a larger version of the same one, which is why the market has no independent tool for it

Talk to us about a collective project
AspectMaison individuelleHow PACDim handles the copropriete
SystemOne machine, one dwellingTotal load across every apartment
DistributionDirect supplyHydraulic circuit calculation
NoiseRarely decisiveNF S 31-010 compliance check
ApprovalNot requiredAssemblee generale presentation
DiagnosisIndividual DPEDPE collectif integration
SubsidyMaPrimeRenov individualMaPrimeRenov Copro, per apartment

Independent by construction

We hold the catalogue of all major manufacturers rather than one, because a recommendation is worth something only if the tool making it has no interest in the answer

ToolMaisons individuellesCoproprietesFrench standardsIndependent of manufacturers
Free national tool
Imported design tools
Manufacturer software
Spreadsheets and hand calculation
PACDim

Selection is made on required capacity, seasonal performance for the climate zone, budget and subsidy eligibility, and every recommendation carries a written reason the professional can read and challenge

Written into the French framework

A design tool is useful only if its output is accepted by the certification bodies and the subsidy administration, so the framework is implemented rather than referenced

NF EN 12831
The reference method for design heat load, implemented directly in the calculation engine
RE2020
Compliance checks and reporting carried into the generated documents
RGE QualiPAC
Attestation generated automatically with the project file
MaPrimeRenov
Eligibility filter on equipment and application file produced from the calculation
CEE
Certificates included in the payback shown to the household
NF S 31-010
Acoustic check, decisive for collective installations
DPE and DPE collectif
Diagnostic data integrated for individual and collective projects
RGPD, EU hosting
Project and building data hosted in France, held within EU jurisdiction throughout its lifecycle

How we build, and what we refuse

Each one is written with the behaviour it requires and the way it can be checked, because a value nobody can verify is decoration

P1

Accuracy before comfort

We give the number the standard produces, not the number that is comfortable to give, and where the result differs from what was expected we show why rather than softening it

Verified against reference cases on every build
P2

Independence is not negotiable

We hold the catalogue of every major manufacturer, and no commercial relationship influences a ranking

Every recommendation carries a reason that can be challenged
P3

The professional time is the product

We measure ourselves in hours returned rather than features shipped, and any capability that adds minutes to the working day is refused

Seven to ten hours of design work reduced to one and a half
P4

Everything must be defensible years later

A calculation supporting a subsidy file has to be reproducible long after it was issued, by us or by anyone examining it

Each document stores its inputs and the engine version
P5

Honest about what is not yet built

We say plainly which modules are running and which are scheduled, and we publish our own unflattering figures rather than waiting for them to be found

Module status stated openly on this site

Priced against the hours they return

A subscription is repaid by the time saved on the first few projects of the year, which is the threshold that makes the decision easy

Starter
The artisan installer working alone or in a pair
€590/ year
  • Up to 50 projects a year
  • Maisons individuelles
  • One user account
  • Ten main manufacturers
  • Note de dimensionnement in PDF
  • Coproprietes
  • Performance simulator
Most chosen
Pro
The installation company of three to ten people
€1,490/ year
  • Unlimited projects
  • Maisons individuelles and coproprietes
  • Up to five users
  • Full manufacturer catalogue
  • Complete document set with subsidy files
  • Performance simulator
  • Email and chat support within a day
Enterprise
Thermal engineering bureaus and copropriete syndics
€4,990/ year
  • Everything in Pro
  • Unlimited users
  • White label documents
  • API access to your own systems
  • Priority catalogue updates
  • A named contact on our side

Prices excluding VAT, billed annually

Two engineers, twenty five years of practice

The calculation method, the architecture and the first working version of the platform were designed and built by the founders, not outsourced

Mohamed Monasef
Mohamed Monasef
Co-founder / Chief Executive Officer

Electrical engineer trained at ENSEM Casablanca, with more than eight years on large energy infrastructure including a 2x490 MW gas turbine project, a 225 kV solar plant, and the Koudia Baida and Taza wind farms

At PACDim he owns the regulatory interface, the manufacturer partnerships and the commercial strategy, and he carries the relationship with the certification and subsidy bodies whose acceptance the product depends on

  • OwnsStrategy, partnerships, regulatory relations, key accounts
  • TrainingEngineering degree, electrical engineering and embedded systems, ENSEM Casablanca
  • BackgroundGrid integration, load calculation, IEC standards and certification
ArabicFrenchEnglish
Olufisayo Emmanuel Ojo
Olufisayo Emmanuel Ojo
Co-founder / Chief Technology Officer

MSc Mechanical Engineering awarded Summa Cum Laude, Incorporated Engineer with the UK Engineering Council, with eighteen years in infrastructure design including water treatment plants from 2 to 70 MGD and more than 2,000 km of pipelines

At PACDim he owns the architecture, the calculation engine and standards compliance, and the hydraulic and thermal work that sits at the centre of the collective building module is his daily discipline

  • OwnsArchitecture, calculation engine, quality and standards compliance
  • TrainingMSc Mechanical Engineering, University of KwaZulu-Natal, BEng University of Portsmouth
  • BackgroundHydraulic and thermal calculation, documentation to international standards
EnglishI.Eng, UKCORENIET

Tell us about your projects

Send the kind of buildings you work on and we will come back with a sizing check on one of them, run on the platform

  • 01A reply from one of the founders, not a queue
  • 02A worked example on a building you actually surveyed
  • 03An honest answer on what is running today and what is scheduled

Prefer email, write to contact@pacdim.com

We answer within two working days

Message received

Thank you, we have your request and one of the founders will write back within two working days, from contact@pacdim.com