Air tightness testing is an essential step in ensuring energy efficiency and environmental control within buildings. This process not only helps to identify leaks and drafts that can lead to higher energy costs but also plays a crucial role in maintaining the durability and comfort of a structure. While there are several methods to measure the air tightness of a building, the pulse test and blower door test are two of the most popular and widely used.
In this guide, we’ll explore and compare the benefits and limitations of pulse testing and blower door testing, how each method works, and the scenarios in which one might be preferred over the other. Whether you’re a building professional, an architect, or a homeowner looking to improve your property’s energy performance, understanding the nuances of these tests is key to achieving optimal results.
At Falcon Energy, we’re air tightness testing specialists and our services for both commercial and residential properties includes blower door testing (not pulse testing). Our air tightness tests are available nationwide and are completed by fully qualified, experienced testers.
For a free no obligation quote, speak with us today by calling 01403 253439.
Our air tightness testing services
Understanding air tightness testing
The primary goal of air tightness testing is to identify leaks in the building envelope – the physical barrier between the conditioned interior and the unconditioned exterior of a building. These leaks can occur around:
- doors
- windows
- joining sections of walls
- various other points throughout a structure
By detecting these leaks, builders and homeowners can take action to seal the building, improve its energy performance, and ensure compliance with local building codes that often set specific standards for air permeability.
Air tightness is measured in terms of the volume of air that leaks out of or into the building per hour per unit area of the building’s envelope at a given pressure, expressed as cubic metres per hour per square metre (m³/h/m²) at 50 Pascals (Pa) of pressure. The testing is usually conducted using equipment that either pressurises or depressurises the building to simulate windy conditions and allows for the measurement of airflow rates.
Testing is typically required at several stages of construction and can be part of certification processes for energy-efficient housing standards.
Learn more about air tightness testing for new builds
What is pulse testing?
The pulse test for air tightness is a modern method that accurately measures a building’s air leakage using pressure shockwaves. It provides a quick, simple assessment without a door fan, delivering precise results in real-world conditions. Developed by the University of Nottingham, it is an alternative to the blower door test.
How does it work?
Pulse testing measures a building’s air tightness by utilising a pressure shockwave sent out from a central box. This shockwave creates a temporary pressure difference within the building, allowing for the calculation of air tightness without the need for a door fan. After the pulse, the equipment measures the rate at which the pressure returns to normal. This decay rate is an indicator of the building’s air tightness. The quicker the pressure normalises, the more airtight the building is considered to be.
Operating at a pressure differential of 4Pa, pulse testing provides an accurate representation of real-world conditions. Its quick and simple nature makes it a less disruptive method compared to traditional air leakage testing. Requiring minimal equipment, it can even be carried out with occupants present, making it efficient and convenient in assessing a building’s air tightness.
When is it used?
The pulse air tightness test is particularly useful when there’s a need to assess the air tightness of a building quickly and accurately, and when it may not be possible to vacate the building. It is ideal for smaller buildings and buildings with a simpler layout.
It’s commonly used during the construction phase to identify any leakage points in the building fabric, and is also valuable for retrofit projects aiming to improve energy efficiency and indoor air quality.
What are the main benefits and limitations?
- Quick and straightforward
- Minimal disruption to occupants
- Not universally accepted by building regulations
- Not always applicable to highly airtight spaces
The pulse testing method proves to be a low-impact alternative to traditional air leakage testing, providing a quick and straightforward measurement of air leakage at 4Pa. The test is completed swiftly – it’s possible for it to be completed within 10 minutes – with minimal disruption to occupants. This method is particularly useful for rapid spot checks and for buildings that are in use and cannot easily be vacated for longer testing periods.
However, despite its advantages, pulse testing may not be universally accepted by building regulations and could present limitations for extremely airtight dwellings.
What is blower door testing
Blower door testing operates by using a blower door, which is a powerful fan mounted into the frame of an exterior door, to create pressure differentials within a building, allowing for precise airflow measurements.
This method is commonly used to assess a building’s airtightness and detect areas of leakage accurately. This test is widely accepted, essential for compliance, and provides detailed data on a building’s air tightness.
How does it work?
Blower door testing works by using a powerful fan to create pressure differences inside and outside the building, allowing for precise measurement of air leakage. The duration of a test can vary depending on several factors, but typically, it takes about 1 to 3 hours to complete.
Here’s how it works:
- The blower door fan creates pressure imbalances to determine the airflow through the building
- Measurements are taken at a standard pressure of 50 pascals (Pa) to ensure consistency
- The test can either depressurise or pressurise the building to accurately assess air leakage
- By identifying specific air leakage points, blower door testing effectively determines the building’s overall airtightness
The comprehensive approach measures the overall air tightness of a building and identifies specific problem areas where air leakage is occurring. Infrared cameras can also be used during the test to visually identify air leaks. This information allows contractors and homeowners to reduce energy costs, increase comfort, and improve indoor air quality by completing targeted air sealing work based on the detailed results.
When is it used?
A blower door test is used during energy audits and building evaluations and ensures new constructions meet specified air tightness standards. This testing is also crucial for establishing proper HVAC sizing by providing accurate air exchange rates, which helps in avoiding system over-sizing or under-sizing and ensures energy efficiency.
These tests are mandatory in many regions for compliance with environmental regulations and building codes, particularly after significant renovations or in new construction to verify that sealing and insulation meet required standards. This ensures a healthy, comfortable, and sustainable living environment while optimising energy use.
Compared to pulse testing, it is suitable for larger, more complex structures and offers more detailed and accurate data collection.
What are the main benefits and limitations?
- Detailed and accurate data collection
- Suitable for building regulations
- Suitable for energy efficiency certifications
- Can be time consuming
- Requires a building to be vacated
Blower door tests offer accurate and detailed data to evaluate a building’s air tightness. They identify air leakage points, enhance energy efficiency, improve indoor air quality, and ensure comfort. They serve as essential tools in verifying compliance with building codes and green certification standards. These tests help manage moisture within the building structure, thereby extending its durability.
However, blower door tests can be costly and time-consuming, particularly for larger or more complex structures, and require significant technical expertise for accurate data interpretation. The testing process can disrupt normal building operations, as it necessitates vacating the premises and sealing all openings. Blower door tests may need supplementary tools to locate specific leak points and require periodic retesting to address new leaks as buildings age.
Which test is right for you – pulse test or blower door test?
Choosing between a pulse test and a blower door test depends largely on your specific needs and circumstances. Here’s a brief look at which test might be more suitable for you:
Pulse test
This method is ideal for quick assessments and is less invasive, making it perfect for buildings that are occupied or for preliminary checks during the early stages of construction. It’s particularly useful if you need a fast overview or are dealing with smaller buildings.
This test is also cost-effective due to its rapid execution and minimal setup requirements, which makes it a great option for routine maintenance checks to ensure ongoing compliance with building standards.
Blower door test
If you require a more detailed analysis, the blower door test is the better choice. This test is comprehensive, providing exact measurements of air leakage and identifying specific leak points across the entire building envelope. It is essential for final testing in new construction or major renovations to meet regulatory requirements and to qualify for energy efficiency certifications. While more time-consuming and disruptive, the thoroughness of the test makes it indispensable for ensuring optimal building performance and energy conservation.
Essentially, if quick, general assessments are needed, particularly in smaller or occupied spaces, the pulse test could be ideal. For detailed diagnostics and regulatory compliance in larger or newly renovated buildings, the blower door test is more appropriate.
Book your blower door test today
At Falcon Energy, we’re available to carry out blower door tests as part of our air tightness testing services. Our testers are fully trained and experienced and will provide you with a detailed report and insightful advice on reducing air leakage in your property.
Speak with us today for a free no obligation quote and to book your test at a time convenient to you.