Designing the right system shouldn't mean hours with a spreadsheet. PureClima's free online tools give engineers, installers, and specifiers instant, accurate results — from cooling load calculations to refrigerant pre-charge and everything in between. No subscription, no login. Just the numbers you need, when you need them.
Use the free tools
Calculate before you buy. Use our free online tools to size ducts, estimate cooling loads, configure plenums, check refrigerant charge, and more — no login required.
Place your order
Once your specification is confirmed, add products to your basket and check out online. Trade account holders benefit from exclusive pricing. Need a quote first? Request one free.
Order confirmation
You'll receive an instant email confirmation with your order summary and invoice. Our team reviews every order and will be in touch if any technical clarification is needed before dispatch.
Delivery to your door
Your order is carefully packed and dispatched to your site across the UK. You'll receive tracking information so you always know when to expect your products.
Professional HVAC Calculators & Design Tools — All Free
Whether you're sizing ductwork for a commercial fit-out, configuring a plenum for a gypsum diffuser installation, or verifying refrigerant charge on a new system, our engineering tools are built to save you time and reduce costly specification errors.
All tools are available online, browser-based, and free to use for every trade professional, consultant, or facilities manager working on projects across the UK.
Why Engineers Choose PureClima Tools
- Free to use — no registration, no paywall, no time limit
- Browser-based — works on desktop, tablet, or mobile on any modern browser
- UK-relevant — aligned with British standards and typical UK installation practices
- Built for professionals — results you can trust and take into the design process with confidence
Designed for UK HVAC Professionals
PureClima is a UK-based supplier of premium ventilation and air distribution products, including frameless gypsum diffusers, plenum boxes, silencers, and grilles. Our free tools have been developed to complement the products we supply and the projects our customers work on — from high-end residential installs to large-scale commercial HVAC systems.
We understand that getting the specification right matters. These tools exist to make your job easier, whether you're on site, in the office, or responding to a client brief at short notice.
Our Free Tools
Plenum Configurator
Match the right plenum to your ceiling diffuser with confidence. Designed to work alongside PureClima's range of frameless gypsum diffusers, the plenum configurator helps you select the correct dimensions, connection type, and configuration for your air distribution setup — ensuring a clean finish and efficient airflow from day one.
Perfect for: Installers specifying PureClima diffuser systems, interior contractors, HVAC engineers
Cooling Calculator
Accurately estimate the cooling capacity required for any space. Input room dimensions, occupancy, glazing, and heat gains to get a reliable BTU/kW output. Ideal for specifying split systems, fan coils, or ducted air conditioning for residential and commercial applications.
Perfect for: Air conditioning engineers, M&E consultants, surveyors
Duct Sizing Tool
Get the right duct dimensions first time. Our duct sizing calculator uses velocity and pressure drop methods to determine the optimal duct cross-section for your airflow requirements. Supports both rectangular and circular ductwork, helping you balance system performance with installation constraints.
Perfect for: Ventilation contractors, ductwork fabricators, HVAC designers
Ventilation Calculator
Ensure your ventilation system meets the required air change rates for any room type. Calculate supply and extract volumes against occupancy levels, room usage, and building regulations guidance. Useful for domestic MVHR design, commercial fresh air systems, and compliance checks under Approved Document F.
Perfect for: Ventilation engineers, building services consultants, domestic installers
Refrigerant and Pre-Charge Calculator
Eliminate guesswork on refrigerant pipe runs. Enter your system type, pipe length, and diameter to calculate the exact refrigerant pre-charge required for your installation. Reduces the risk of under- or over-charging, protecting system efficiency and equipment longevity.
Perfect for: F-gas certified engineers, air conditioning installers, commissioning engineers
Silencer Configurator
Select and configure acoustic attenuators for any ductwork application. Input system parameters and airflow data to identify the right silencer type, insertion loss, and pressure drop — ensuring your system meets acoustic performance requirements without compromising airflow.
Perfect for: Acoustic engineers, M&E designers, contractors working on noise-sensitive projects
Interactive Psychrometric Chart
Visualise air conditions in real time. Our browser-based psychrometric chart lets you plot and analyse temperature, humidity, enthalpy, and dew point — essential for HVAC system design, troubleshooting, and commissioning work. No specialist software required.
Perfect for: HVAC engineers, energy assessors, building services students and educators
Helping HVAC Professionals Get It Right First Time
Good system design begins with accurate data. The difference between a well-performing installation and a costly remedial job often comes down to the quality of the calculations made at the specification stage. PureClima's engineering tools put reliable, fast calculation in your hands — so you can specify with confidence and install with precision.
From cooling load to duct velocity, from refrigerant charge to acoustic attenuation, each tool addresses a specific challenge faced by HVAC professionals on real UK projects. And because they're online and free, there's nothing standing between you and the information you need.
Explore the full range below and bookmark this page as your go-to HVAC engineering resource.
Frequently Asked Questions
Are these tools really free to use?
Are these tools really free to use?
Yes — all tools on this page are completely free. There is no account required and no usage limits.
Can I use these tools on mobile or tablet?
Can I use these tools on mobile or tablet?
All tools are browser-based and accessible on any modern device, including smartphones and tablets.
Are the calculations aligned with UK standards?
Are the calculations aligned with UK standards?
Our tools are designed with UK installation practices and relevant British standards in mind. Always cross-reference against current project specifications and applicable regulations.
Do I need to create an account?
Do I need to create an account?
No. All tools are open access — simply click and start calculating.
Who are these tools designed for?
Who are these tools designed for?
They are built for trade professionals including HVAC engineers, ventilation installers, M&E consultants, building services designers, and F-gas certified engineers. They are also useful for students and educators in building services disciplines.