Call
+44 345 6465 454
callcenter person
Get a quote

atspace engineer with checklist

The methodology for measuring air tightness in a building is to either pressurise or depressurise the whole building. Air leakage can then be measured to give an indication of the leakage rate or air permeability. 

Depressurisation is created by removing air from the building, and pressurisation is the introduction of air to the building. To carry out this process, a temporary door frame is installed within one of the external doors, and a fan is fitted within the temporary frame. A pressure tube is placed in the middle of the building, and another to the outside of the building. These 2 tubes measure the external pressure and the internal pressure, known as the Bias pressure. These measurements are taken before and after the test as a bench mark. Pressure tubes are connected to the fan. All pressure tubes and a fan controller lead are connected to a pressure gauge. 

 The air tightness test is affected by weather conditions, barometric pressure, temperatures inside and outside the building, and wind speed. 

The leakage rate is measured against the total metres squared (m2) of the envelope's surface area. The buildings envelope is the total surface area of the floor, external walls and roof. This measurement is calculated so that a result can be determined. 

The air tightness test of a building is guided by a set target within the energy calculation (SAP or SBEM). The overall calculation determines the target figure. The better the air test result, the less leaky or draughty your property will be. As a minimum, the target figure must be met or bettered to pass the air tightness test. 

Temporary sealing for the air tightness test is only permitted on extraction fans, ventilation systems or unconnected waste pipes. All windows and doors should be fully fitted and working. Make sure they are well sealed prior to any test. Access doors, including internal garage doors, cannot be temporarily sealed in advance of the test and should be air tight. Trickle vents closed. 

The fan is run, and the pressure of the building is changed within 10 pascal increments. As the pressure is changed, the flow rate measured through the tubes connected to the fan is noted. This is the flow of air leaving or entering the building, depending on whether the building is being depressurised or pressurised. The flow rates and pressures are run through a software program, and a result is calculated. 

The maximum leakage rate allowed within the energy calculation is 10m3/(hr*m2) @50 Pa, but this number could be lower, as it is common for the energy assessor to lower the target score to enable the energy calculation to pass. 

By building to air tightness standards and being aware of building a tighter property, building standards will improve, giving a better end product for the client, and the overall running costs and efficiency of the property will improve. 

Air tightness testing is a mandatory requirement of Part L of the building regulations for a new build property, whether residential or commercial. All new build buildings require.

  •  
Previous Article: What is a Good Air Tightness Result? Next Article: What Happens if The Air Test Fails?

"ATSPACE has provided , and continues to provide, an outstanding service to a high standard."

Andy Gilliver, Persimmon Homes

Results

 

 

"A very prompt and efficient service that dealt with every aspect of my requirements in a professional way. If you're in need of any testing requirements to meet building regulations I'd recommend ATSPACE every time."

Mynott Associates Limited

Results

"We have Found ATSPACE Services reliable, professional and friendly at a competitive Price."

Lyndsay Thrower, Taylor Wimpey

Results

"Thank you for the Smoke shaft Air Pressure Test. The whole experience with ATSPACE has been a pleasure from the start and we are looking forward to working with you on the next job.”

Brian Keane, C.E.O, Cameron Ventures Group

Results

"Just a note to thank ATSPACE for the excellent service received on this most recent project. Your engineer put himself out to ensure that the Smoke shaft Air Pressure Test was carried out with the minimum of fuss (in a very tricky environment) and was a pleasure to have on site."

Olly Wigg Director, Bowson Leeway Homes

Results

Testimonials

Trusted by 9K+ businesses
hill
taylor wimpey
logo-mace
Willmott_Dixon_logo
Copyright © 2022 Atspace Ltd. Website Design by Insynth Marketing Ltd.