Experimental Assessment of Different Sealing Methods for Windows to Improve Building Airtightness in UAE Residential Buildings

Abstract

If infiltration is uncontrolled and admits unconditioned air, the results will be undesirable. Controlling this problem will increase thermal comfort and decrease energy consumption. The aim of this paper is to assess the performance of different materials used to improve airtightness, which will increase energy efficiency. This research primarily adopted an experimental approach. A typical residential building in UAE was chosen as a case study. Current airtightness status was measured using a blower door test and infrared technique. Six commonly used materials used for airtightness in UAE were identified and applied in different zones of the building envelope, including exterior walls, door and windows. The test was run before implementing airtightness strategies, following which they were applied for one year. Overall performance and energy reduction were monitored to identify how consumption fell by which method was the most efficient. The results indicate that energy was 3% when applying the 6 different airtightness strategies. The base case energy consumption was 64,287 kWh per year. The energy consumption then decreased after applying the sealants to 62,341 kWh per year. Future recommendations are made to enhance airtightness in residential buildings in a hot and arid climate.

1. Introduction

The energy demand from building construction continues to increase and building sectors are responsible for 36% of global energy consumption and almost 40% of total CO₂ emissions [1]. With buildings in the UAE consuming 80% of the country’s energy, the building sector has a key role to play in terms of energy efficiency [2]. Poor airtightness within buildings will result in high energy consumption. UAE was listed as fifth in terms of CO₂ emissions per capita, with 40% of yearly electric loads coming from HVAC equipment and up to 60% of emissions occurring during the summer [3]. This alarming fact highlights the urgent need for urgent strategies to increase energy efficiency in buildings While attention is generally paid to the installation of the most efficient HVAC systems and thermal insulation in buildings, there has been little focus on the unintentional loss or gain of air from these buildings. In many countries, infiltration is the dominant source of outdoor air. Providing an appropriate comfortable indoor environment at minimal energy costs is a complex optimization process that includes, but may not be dominated by, airtightness concerns [4]. Sinnott (2011) [5] defined airtightness as “the flow through the building envelope as a function of pressure across it and thus leakage testing is based on the fundamental mechanics of airflow”. This means airtightness expresses the resistance of the building envelope to airflow paths in the building. Several studies have found that occupation of the dwelling can cause a 20–100% increase in leakage and there are large effects of weather conditions as well as the age of the construction on airtightness [6]. Thus, the effectiveness of airtightness strategies varies over time. A study in Belgium on the durability of airtightness of passive houses (ACH₅₀ < 0.6 upon completion) reported that the average air leakage of houses increased by 30% just 2 years after the project had been completed [7]. Air leakage typically occurs through cracks and joints in the building envelope and through the use of doors. In the summer, infiltration can bring humid outdoor air into the building, which is also caused by wind, stack effect, and mechanical equipment within the building. Poor airtightness can lead to large infiltration rates, eventually causing an increase in energy consumption [8]. According to the Clean Energy Business Council in 2018 [9], residential buildings consume 18% of the GCC’s overall energy consumption and 43% of its electricity. Several researchers [10] have emphasized that improving the airtightness of buildings will lead to increased energy efficiency and savings. Authors in the UAE [11] have studied the impact of building characteristics and occupants’ behavior on the electricity consumption of households in Abu Dhabi. However, their calculations were not based on the potential impact of infiltration. The authors therefore recommended conducting a future study to assess the impact of airtightness of different type of buildings. Further research is thus needed in the field of airtightness, especially in UAE buildings. Consequently, the aim of this study was to enhance the energy efficiency of buildings while taking into account the airtightness of residential buildings in the UAE. The next section reviews relevant literature in this field.

2. Literature Review

2.1. The Importance of Airtightness in Buildings

To control airtightness factors, it is essential to first understand the contribution of cooling load components. In a medium-size building in the USA, these are 10% for duct leaks, 12% for duct gain, 16% for appliances, 20% for roof, 6% from walls, 30% from windows, and 6% through infiltration [12]. This shows that windows have high potential for heat exchange and addressing this will help to achieve greater airtightness. Previous studies in a hot climate predicted that potential annual cooling load and energy savings will reach 9.3% when accompanied by an 81% improvement in airtightness performance [13]. Numerous studies have highlighted the disadvantages of low-quality construction implementation with respect to airtightness, and concluded that the annual energy consumption of an insulated residence with an ACH rate of 2.5 accounts for poor implementation—roughly the same as a similar uninsulated case in which the ACH rate was 0.25 (29,942 kWh compared to 30,075 kWh). In addition, when altering the ACH rate, the cooling load demand remained steady at approximately 25,000 and 20,000 kWh for uninsulated and insulated cases, respectively [14]. Nevertheless, improving airtightness also helped to reduce the heating load, thus reducing the energy consumption up to 36% of the annual energy consumption [15]. Although the UAE produces its own energy, its energy balance in 2017 reached an overall consumption level of 110.60 billion kWh of electric energy per year, an average of 11,766 kWh per capita [16]. According to the Emirates Green Building Council, [17] the common points of air leakages are distributed as follows: 2% in electric outlets, 36% in floors, walls, and ceiling, 17% in ducts, 15% in pluming, 13% in doors, and 12% in windows. Unfortunately, in the UAE the airtightness regulations are not especially strict and therefore design teams are not particularly concerned with the airtightness of buildings (unless it has been specified by the client). To understand this, it is important to review the global experience in this field.

2.2. The Global Status of Building Airtightness

Improving airtightness has multiple benefits. For instance, one study [18] linked an improvement in thermal comfort and air quality with improved airtightness in low-income housing in Spain. An important study in Finland [19] concluded that in residential buildings, the construction method and insulation materials have an effect on airtightness performance that is distinct from the choice of structure, stories, and the ventilation strategies of the construction technology. Based on extensive airtightness measurements carried out in 159 social housing buildings in Southern Europe, another study [20] proposed the climate zone and age or year of construction as two more factors fundamental in determining airtightness performance. An experimental study in Korea [21] of two- story office buildings concluded that airtightness values may differ according to the measurement method and size of the buildings.

Table 1. Summary of global studies on building airtightness status.

No.	Authors	Title	Aim and Method	Country	Main Findings	Citation
1	Bossche and Janssens, 2016	Airtightness and watertightness of window frames: Comparison of performance and requirements	This paper reports the results of 437 windows tested in lab conditions between 1997 and 2012. These include aluminum and wooden windows, and single, double, composed, and sliding windows.	Belgium	In terms of airtightness, aluminum and wood windows exhibit similar performance, based on surface area averaged values. Sliding windows are almost 2.5 times leakier than single windows. Overall, 75% of all windows have an air leakage rate below 1.05 m3/h·m2.	[22]
2	Ji and Duanmu, 2017	Airtightness field tests of residential buildings in Dalian, China	This paper investigated the airtightness performance of ten detached houses in a cold area using the “blower door test”. In addition, the thermal infrared imager and smoke pencil were used to identify typical points of air leakage in the building envelope.	China	The main cause of high air leakage was the fact that the frames of window were not fitted correctly and the draught seal was deformed, leaking air into the house. The air change rate for a pressure difference of 50 Pa of the tested houses varied from 1.89 h_1 to 0.84 h_1 with a mean value of 1.42 h_1.	[23]
3	Mortensen and Bergsøe, 2017	Airtightness measurements in older Danish single-family houses	Authors measured 16 single-family houses built between 1880 and 2007. The airtightness of the building envelope was measured using the blower-door technique in accordance with EN ISO 9972.	Denmark	The airtightness of the building envelopes ranged from 1.1 to 5.8 L/(s·m2) at 50 Pa. This measurement is below the Danish Building Regulations standard of 0.31/(s·m2).	[24]
4	Tanyer et al., 2018	Assessing the airtightness performance of container houses in relation to its effect on energy efficiency	The study examined the airtightness performance of four types of commonly used container houses from an energy point of view. Measures were taken before and after sealing was applied.	Turkey	An 18% improvement in the performance of the container houses resulted in a reduction of 9.3% in annual energy consumption. This reduction was not enough to raise its energy rating category.	[13]
5	Colijn et al., 2017	Evaluating the effectiveness of improved workmanship quality on the airtightness of Dutch detached houses	Using a blower door test, the specific leakage rate of 44 detached houses was measured to evaluate the modest technical improvements and coaching of construction teams.	Nether-lands	The specific air leakage rate (w10) was reduced significantly from 0.678 dm3/s·m2 (n = 44, SD = 0.296) to 0.498 dm3/s·m2.	[25]
6	Feijó-Muñoz et al., 2019	Airtightness of residential buildings in the continental area of Spain	129 dwellings were tested, including different typologies and periods of construction, in order to detect air leakage through the envelopes of existing housing stock in the Continental climate.	Spain	Single-family dwellings were found to be more airtight than apartments, as the mean air permeability rate at 50 Pa (q50) was 5.4 m3/h·m2 and 6.8 m3/h·m2, respectively. The mean air change rate at 50 Pa (n50) was 6.1 h−1 for single-family dwellings and 7.1 h−1 for multi-family housing.	[26]
7	Alev et al., 2017	Airtightness improvement solutions for log wall joints	Air leakage was tested using a Scandinavia saddle notch or dovetail notch in an airtightness measuring camper in a laboratory setting. Common sealing materials were applied.	Estonia	Peat moss reduced the air leakage of the Scandinavian saddle notch by 77% and that of the dovetail notch by 84%. Sealing material was a special joint sealant that reduced the air leakage of Scandinavian saddle notch by 87% and that of the dovetail notch by 70%.	[27]
8	Cuce, 2017	Role of airtightness in controlling energy loss from windows: Experimental results from in situ tests	This study measured the effect of air leakage on overall heat transfer coefficient (U-value) of conventional air-filled double glazed windows in a traditional two story dwelling in Nottingham.	UK	A 33% reduction in heat loss can be achieved by improving the airtightness of the windows	[28]

summarizes the results of recent studies of building airtightness, which will form a point of comparison for the results of the current study.

2.3. Methods for Measuring Airtightness

Small cracks and crevices can cause a gap where air exchange will take place. Multiple methods can be employed to accurately measure air infiltration. The blower door technique is now an extremely popular and reliable method for measuring air infiltration. This method comprises three components: a calibrated fan, a door panel system, and a device to measure fan flow and building pressure. The blower door fan should be sealed into an exterior doorway using the door panel frame. The fan then blows air into or out of the zone or outside the building, which creates a small pressure difference between the internal and external environments. The most common method is to suck air out of the room using the blower door. As a result, the air pressure inside the room is lower than it is outside air; usually the difference is about 50 Pascal. In the context of Ireland, another researcher evaluated Irish dwellings using a standard blower door test and found that a 22% improvement in airtightness may save an estimated average of 361 kWh per dwelling [29]. The blower door method has also been used in Turkey to test the effect of airtightness on energy consumption in container houses. These authors found that an 81% improvement might lead to a 9.3% reduction in annual energy demand [13]. Another notable method is the use of a thermal camera. Due to the pressure differences between indoor and outdoor environments, the air outside will rush into the building through the cracks or joints. This air will cool the location where a crack is located. This temperature discrepancy will clearly show up in the thermal image as a cold spot or cold area, allowing the operator to accurately locate and map the air infiltration pathway. This method will help inspectors and researchers detect not only air infiltration but also insulation defects, thermal bridges and moisture problems. This method has been adopted by numerous researchers. For instance, a study in China used the infrared camera to measure indoor and outdoor parameters such as air velocity, temperature, and pressure. Cracks were then identified by means of theoretical heat transfer and fluid mechanics analysis. The authors concluded that the error was within 3% [30]. Some researchers have adopted both methods; for example, a study in Australia [31] used both the blower door and thermal imaging to test 125 houses, providing the researchers with accurate measures of airtightness. Finally, simulation software can also be used [32] as well as manual calculations [33]. Having reviewed the literature, the next section describes the methods adopted for this research.

3. Methodology

3.1. Research Design

A medium residential building, a villa in Dubai, was chosen as a base case for this research. Figure 1 illustrates the case study and

Table 2. Specifications of case study.

Characteristic	Value	Description
Floor area (m2)	2300 (length 54.3 m × width 42.4 m)	Fully occupied
Number of floors	2	2
Floor to ceiling height (m)	2.90 m	Unified throughout the villa
Back yard area	45 m2	Garden
Window-to-wall ratio (%)	25.4
Building Envelope
Walls U-value	W/m2K
Roof U-value	W/m2K
Window U-value	W/m2K	Per Dubai Municipality Standards
SHGC	86%	Solar Heat Gain Coefficient
Foundation	15.2 cm concrete slab-on-grade + insulation per UAE Building Code
HVAC	HVAC is on the whole year at 21 °C	Cooling only

presents the specifications of the villa. The actual energy consumption was collected by the villa owners from September 2017 to August 2018. The researcher sealed all cracks and gaps in the houses except for windows/door glazing frames, as these were the main areas that needed to be studied. The gaps therefore sealed included: ends of floor joists, joist hangers, around doors, beneath doors and door frames, along the top and bottom edges of skirting boards, between and around sections of suspended floors, around loft hatches, through the eaves, around roof lights, through gaps behind plasterboard, cracks and holes, around the supplies from external meter boxes, around a wall-mounted fan, around pull switches, boiler flues and heating pipes, around waste pipes passing into floor voids and through recessed spotlights. Thus, the only parts left untouched were the glazing windows and the glazing doors along with their frames. Following this procedure, the blower door test was conducted on 1 September 2018 to determine the airtightness of the building. According to European Commissions, the blower door test was used first in Europe to measure the air leakage of the building envelope, but is now explicitly described in the European Standards EN-13829 [34]. The blower door test was conducted on 6 zones where the window in each was treated using one of the 6 sealing methods, which comprised 2 types of sealants, 2 types of tapes, and a foam and liquid membrane.

Table 3. Test zones and sealing strategies with their specifications.

Zones	Function	Room Area	Glazing Area	Sealing Type	Image	Specifications
Zone 1	Master Bedroom first floor	15.51 m2 (3.3 × 4.7)	4.38 m2 (0.8 × 0.6 × 2) + (0.80 × 2.14 × 2)	Fiberglass Cloth Aluminum Foil Tape		Peel adhesion 18 N/25 mm Tensile strength 45 N/25 mm Elongation: 3% Reflectivity: 97% Emissivity: 0.03 Tear strength: 226.4 N/25 mm
Zone 2	Studio room	12.24 m2 (3.6 × 3.4)	1.52 m2 (1 × 0.76 × 2)	Polyure-thane Foam Tape		Quick and easy to apply Seals against uneven surfaces Impregnation: Synthetic Resin Air-permeability (pressure of 10 Pa): DIN 18542; a < 1 m3/(h.m.(daPa)) Thermal conductivity: 0.046 W/mk
Zone 3	Children’s room	14.8 m2 (3.7 × 4.0)	2 m2 (0.8 × 1.25 × 2)	Foam		Pro Foam Window Application temperature +10 °C to +30 °C Compressive strength (10%): 9 kPa It also functions as sound insulation
Zone 4	Home office	15.2 m2 (3.8 × 4.0)	4.28 m2 (2.14 × 1 × 2)	Liquid Membrane		Color is black (dry) Waterborne polymer paste reinforced with fibers Application Temperature: +5 °C SD value: >10 Density: 1.2 kg/L Expected Airtightness: 0.07 m3/H.M (50 Pa); EN 12114: 2000 Elongation: >230%
Zone 5	Kitchen first floor	14.7 m2 (4.2 × 3.5)	2 m2 (0.8 × 1.25 × 2)	Sealant 1		For internal and external use Solvent-free and odorless Adhesive sealants based on modified acrylate dispersions Temperature resistance −40 ≤ t ≤ +100 (after curing)
Zone 6	The whole villa excluding the specified test zones	64.44 m2 Living room ground floor (6.0 × 4.7) + Dining room ground floor (3.6 × 2.4) + Family room first floor (4.6 × 6.0)	12.53 m2 Living room ground floor (1 × 2.14 × 2) + Dining room ground floor (1 × 2.14 × 2) + Family room first floor (0.72 × 1.38 × 4)	Sealant 2		Raw material base: polymer dispersion Color: light blue Consistency: pasty-elastic Application temperature: +5 °C to +40 °C

explains each zone in terms of the room area, glazing area, and presents images of the products along with their specifications. Each product was applied inside and outside around the window frames for zones 1, 2, 3, 4, and 5 separately. Sealants were applied inside and outside on the edge of the glazing. Figure 2 illustrates the window sections and marks the exact location of the sealant application. All these zones were then closed and the test was conducted for the entire house, including ground floor glazed door frames. The results were then obtained and compared, following which, the energy consumption for one year was monitored to study the effect in each zone.

3.2. Test Procedure

The test initially took place on 1 September 2018 without any glazing improvement; this was the “baseline” stage. The airtightness of the villa envelopes was measured using a fan pressurization test in each zone separately, where the fan was used to create a series of pressure differences across the building envelope between the building interior and the outdoors. The test method complied with ASTM Standard E779 (ASTM, 2010) which describes the fan pressurization test procedure in detail, including specifications of the test equipment and analysis of the test data [35]. The tenants were asked to leave the house for three days. Precautions were taken to ensure there was minimal damage to the glazing windows and doors. The HVAC system was completely shut off and emergency contacts were collected. The test itself involved: (1) collecting baseline and induced envelope pressure and test fan flow data using a central computer; (2) analyzing data using the methods in E779 while still in the test building with the test equipment still installed; (3) identifying problems with test data, correcting problems in the building test conditions if necessary (e.g., doors blowing open), and collecting additional data to correct the problem; (4) reporting the data in terms of CFM (m³/h) at 50 and 75 Pa induced envelope pressure, CFM/ft² (m³/h per m²) above grade enclosure at 50 and 75 Pa, and CFM/ft² (m³/h per m²) of total enclosure at 50 and 75 Pa; (5) reporting the test results for the baseline case in terms of the airflow rate at a certain reference pressure difference divided by the building volume, floor area, and envelope surface area. On 2 September 2018, the sealing company was received in the villa and each zone was sealed. This was the “base case” stage. Figure 2 illustrates the structural details and sealing locations of the glazing windows. On 3 September 2018, the same procedure using the blower door was conducted (defined as the “airtight case” stage). Energy reduction was monitored from 4 September 2018 till 4 September 2019. The results were then collated and are analyzed in Section 4. When the openings of the air movement were temporarily covered, the measuring devices were connected to the internal and external referencing pressure tubes. The differences in zero flow pressure were recorded where (Δp_0,1+) is the average of the positive values recorded over a minimum of 30 s, (Δp_0,1-) is the average of the negative values recorded over a minimum of 30 s, and (Δp_0,1) is the average of all values recorded over a minimum of 30 s. Adequate time was allowed for induced pressure to stabilize throughout the building envelope. Tenants were assured that the villa would not become over-pressurized (>100 Pa) as this would have presented a risk to the internal finish and fabric of the villa.

3.3. Thermal Imaging

Thermal imaging testing is an important quality control measure with respect to assessing building airtightness. It is difficult to identify small air gaps using building airtightness testing alone, therefore, in this research, a camera was used to identify patterns of heat loss that are invisible to the naked eye [36]. The thermal imaging and blower door test complement each other and their combined use quickly indicated air leaks within the case study. Initially, the thermal imaging helped the researcher to identify the insulation defects in roofs and floors and general air leakage everywhere except the windows. After fixing all these leakages, the glazing was ready for the test. Thermal imaging was used to assess the window performance before and after applying the different sealants. The camera used for this research was a FLIR E95 Thermal Camera. It has a sensitivity of 0.03 °C View and measures temperatures from −4 to 2732 °F (−20 to 1500 °C).

3.4. Mathematical Background

3.4.1. Airflow Rate

To predict the air permeability at 4 Pa and 50 Pa, m³/(h·m²), the following power law equation was used to predict building leakage [37]:

Q = C × ΔPⁿ

(1)

where:

Q = the air leakage rate (m³/s),

C = the flow coefficient m³/(s.Paⁿ),

ΔP = the building pressure (Pa),

n = the pressure exponent.

3.4.2. Fan Pressure (FP)

This is the fan pressure measured when using a self-referenced fan or when the internal zone pressure is negative. When using a fan which is not self-referenced and the zone is positive, fan pressure is calculated by subtracting the measured zone pressure from the absolute value of the fan pressure.

If the Pr A > 0 and fan are not self-referencing, then FP= |PrB| − PrA.

If the PrA < 0 or fan is self-referencing, then FP = PrB.

3.4.3. Airtightness in a Specific Flow Rate

The airtightness for a specific flow rate can be expressed as equivalent leakage area and normalized leakage area. The specific flow rate w₅₀ can be defined as airflow through the building envelope at 50 Pa divided by the floor area at pressure of 50 Pa [38]. Thus:

W₅₀ = Q/A_floor

(2)

where:

W₅₀ = specific flow rate at pressure differences of 50 Pa (cm²),

Q = the leakage air volume flow rate of a fan with a pressure difference of 50 Pa (m³/h),

A_floor = floor area (m²).

3.4.4. Air Permeability

The final air leakage results were expressed as a rate of leakage per hour per square meter of the villa envelope at a reference pressure differential of 50 Pa (m³·h⁻¹·m⁻² @50 Pa). This was calculated by dividing the total leakage flow rate (Q₅₀) by the envelope area (A_E) [39]. Thus:

AP₅₀ = Q₅₀/A_E

(3)

where:

Q₅₀ = C_L × 50ⁿ,

AP₅₀ = air permeability,

Q₅₀ = air leakage rate at a pressure differences of 50 Pa,

A_E = envelope area m²,

C_L = air leakage coefficient,

50ⁿ = differential pressure.

4. Results

4.1. Thermography Analysis

The infrared camera was used to identify the leakage around the windows. The air leakages appear as blue on the IR screen while the blue patches indicate the conductive heat gain.

Table 4. Thermography analysis of the zones.

Zone	Map	Function	Image	Thermography	Comments and Recommendations
Zone 1		Master Bedroom			Warmth can be seen trapped in the door frame The edges must be sealed and treated
Zone 2		Studio Room			No visible anomalies Recommendation is to seal the glazing frame
Zone 3		Children’s Room			Warmth can be seen trapped in the frame Install gaskets to tighten the window
Zone 4		Home Office			Warm air can be seen infiltrating from the bottom of the door Align the door and install the gaskets to avoid leakage
Zone 5		Kitchen			Warm air can be seen infiltrating from the top of the window frame
Zone 6		The villa			Cold air can be seen leaking out from around the door frame Align the door and apply gaskets to avoid cold loss

illustrates the thermal imaging of the baseline where heat and leakages were indicated. The table also suggests solutions and provides feedback on each zone. Obviously, the leakage is apparent in the gaps of the frame, making significant infiltration.

4.2. Baseline Airtightness Performance

In this stage, the blower door test was implemented to assess the six zones. The results are summarized in

Table 5. Base Case Air Leakage Test.

Zone	Airflow at 10 Pa, Q10 (m3/h)	Airflow at 50 Pa, Q10 (m3/h)	Equivalent Leakage Area at 10 Pa (cm2)	Uncertainty	Figure
Master Bedroom	201.41	436.05	243.5	±12.8%
Studio Room	70.000	207.25	48.55	±4.8%
Children’s Room	40.135	107.90	33.51	±8.2%
Home office	59.135	148.80	67.00	±5.0%
Kitchen	179.41	484.95	143.5	±2.2%
The Villa (excluding the specified test zones)	592.45	1551.5	549.5	±4.5%

and clearly show that air leakage was relatively high. The vast majority of airflow at 10 Pa, and Q₁₀ was 592.45 m³/h which appeared in the villa excluding the test zones, followed by the master bedroom which presents 201.41 m³.

4.3. Airtight Case Performance

In this stage, the sealants were applied as per Table 3. Each zone was allocated a certain sealant to test its efficiency.

Table 6. Air leakage test after applying the sealants.

Zone	Airflow at 10 Pa, Q10 (m3/h)	Airflow at 50 Pa, Q10 (m3/h)	Equivalent Leakage Area at 10 Pa (cm2)	Uncertainty	Figure
Master Bedroom	176.71	411.90	183.5	±3.8%
Studio Room	69.170	196.95	59.20	±2.6%
Children’s Room	11.980	34.591	8.545	±4.6%
Home Office	59.040	147.25	52.50	±7.7%
Kitchen	178.65	483.60	143.0	±8.7%
The Villa (excluding the specified test zones)	497.30	1385.0	444.0	±5.4%

presents the results of the leakage test after applying the sealants. These indicate lower air leakage with a different percentage in each zone. The villa, excluding the test zone, had airflow at 10 Pa, the Q₁₀ was 592.45 m³/h and now dropped to 497.30 m³/h. Whereas, the kitchen slightly dropped from 179.41 m³/h to 178.65.

5. Discussion

The results before and after applying the sealants indicate a satisfactory reduction of air leakage in the villa. Figure 3 illustrates the percentage of air leakage drop. This shows that the children’s room experienced the most significant drop of 70.15% in airflow at 10 Pa, Q10 (m³/h), and 67.95% in airflow at 50 Pa, Q10 (m³/h). The smallest drop was in the home office with a fall of 0.16% in airflow at 10 Pa, Q10 (m³/h), and 1.04% in airflow at 50 Pa, Q10 (m³/h). The master bedroom exhibited a significant discrepancy between 10 Pa and 50 Pa. For instance, at 10 Pa, Q10 (m³/h), the drop was 12.30%, while at airflow at 50 Pa, Q10 (m³/h), it was 5.54%. As indicated in Table 3, this suggests that the foam was an extremely efficient airtight strategy.

The energy consumption per year was detected and calibrated with the previous year (when the sealants were not applied). Figure 4 presents the results. This indicates that the base case energy consumption was 64,287 kWh per year. The energy consumption then decreased after applying the sealants to 62,341 kWh per year. This represents a fall of 3% from the base case due to airtightness. According to the passive Haus standards, house airtightness should be under 280 cfm 50. This was achieved in this research. Moreover, it complied with Building Regulations standards (Part L1A) on airtightness, which states that this leakage can be no more than 10 m³/h/m²@50 pa—or 10 m³/h. Additionally, in the UAE, the Dubai Green Building Regulation requires 10m³/h/m² @50 Pa for a building with a cooling load of 1 MW or greater.

6. Conclusions

Air leakage is a major cause of energy loss. Improving airtightness is one of the most cost-effective strategies for decreasing energy loads due to the building envelope. Moreover, the longevity of the materials used to achieve airtightness is vital. The aim of this study was to apply and compare the performance of six different airtightness materials. A typical residential building in UAE was chosen as a case study. The infrared technique was used to indicate the airflow locations. The blower door technique was used before and after applying the sealants. The results demonstrated that the foam was the best sealant as it reduced the airflow at 10 Pa, Q10 (m³/h) by 70.15%, and airflow at 50 Pa, Q10 (m³/h) by 67.95%. The energy consumption therefore dropped by 3% over the course of a year. The findings of this research will inspire building stakeholders in hot regions to choose better and durable materials. For future research, the following suggestions are made: (1) carry out research in different locations with different climatic contexts; (2) test different sealant materials; (3) use a similar method for a case study building with a different function, for example, commercial buildings, and (4) test sealant durability for more than one year.