A Retrofit Glazing System

Abstract

A Retrofit Glazing System (the System) is provided for enhancing the energy efficiency, thermal comfort, and safety of existing building enclosure. The System retains the existing enclosure while incorporating internal glazing system with framing system, vacuum glass, thermal insulation layers and glazing spacer strips to reduce thermal bridging and suppress condensation. The vacuum glass, featuring a vacuum cavity, significantly lowers heat transfer and acoustic transmission. The System is designed to enable a new framing system installation, wherein the new frame and vacuum glass are fixed using pre-assembled sealing strips, stainless steel screws, and support pads, allowing for rapid site installation. The System achieves a reduction of up to 82% in winter heat loss, a 73% decrease in summer solar heat gain with Low-E coating and improved acoustic insulation exceeding 40 dB(A), while also meeting fire resistance and impact safety requirements. The System offers an efficient and cost-effective solution for energy-saving upgrades in existing building enclosure, combining performance with environmental sustainability and aesthetic considerations. 5 2 6 4 3 8 7 1 9 10 20 25 23 42 93 22 S ep 2 02 5 A B S T R A C T S e p 2 0 2 5 2 3 4 2 9 3 2 2 2 0 2 5 5 2 6 4 3 8 7 9 1 0

Description

TECHNICAL FIELD The present relates to the field of building materials, energy efficiency and sound insulation, 5 and in particular to an retrofit glazing system. BACKGROUND OF THE INVENTION In the field of building energy efficiency, old generation of building enclosure frame has long suffered from low thermal performance, poor thermal comfort, and inadequate acoustic insulation. Over time, old generation of building enclosure frame is prone to condensation on 10 the glazing layers or within the framing systems due to temperature differences, leading to fogging, mold growth, and even structural corrosion, all of which negatively affect indoor environment. Although some retrofit solutions attempt to improve performance by partially replacing frames or adding insulation materials, many still lack effective moisture control design, resulting in poor long-term sealing and repeated condensation issues. 15 Furthermore, the thermal performance limitations of old generation of building enclosure systems are particularly pronounced. The enclosure system frames, often made of metal or composite materials, exhibit high thermal conductivity and are prone to thermal bridging. This leads to rapid heat loss during winter and excessive heat gain in summer. Even where certain technologies reduce the thermal transmittance in the central glass area (e.g., lowering heat loss 20 or solar heat gain), the overall energy efficiency of the enclosure system often fails to meet the stringent standards of modern building energy codes, such as Australia's Green Star, LEED, or Passive House certification. The old generation of building enclosure systems also rely on single glazing or simple air gaps for sound insulation, which provide limited protection against high-frequency noise sources such as traffic, making them unsuitable for urban buildings 25 requiring quiet indoor environments. In terms of construction and maintenance, current technologies present additional challenges. Full-frame replacement retrofits require removing the existing enclosure system frame, which incurs high costs, extended construction periods, and significant construction waste. Partial retrofit schemes that retain the frame often lack coordinated design integration, resulting in 30 outdated appearances that compromise architectural aesthetics. Additionally, conventional sealing materials degrade over time, leading to reduced airtightness or water resistance, and 2025234293   22 Sep 2025 ordinary glass typically lacks sufficient impact resistance to meet modern building safety requirements. SUMMARY OF THE INVENTION The invention aims to provide a retrofit glazing system to address the aforementioned technical problems. To this end, the invention provides a retrofit glazing system mounted on the existing enclosure frame. The system further comprises: 1. a thermally insulated decorative cover connected to the indoor-facing side of the existing enclosure frame; 2. a new retrofit glazing frame connected to the interior side of the existing enclosure frame and joined to the thermally insulated decorative cover; 3. a first thermal insulation layer disposed between the new retrofit glazing frame, the existing enclosure frame, and the existing glass; 4. a second thermal insulation layer disposed between the decorative cover and the existing enclosure frame; 5. a vacuum glass mounted within the new retrofit glazing frame, forming an air cavity between the vacuum glass and the existing glass, with a glazing gasket strip and a second sealing gasket strip respectively disposed between each side of the vacuum glass and the new retrofit glazing frame; and 6. a glazing spacer strip disposed within the air cavity, having opposite sides in contact with the existing glass and the vacuum glass, and a lower side in contact with the new retrofit glazing frame and the first thermal insulation layer. Optionally, the new retrofit glazing frame comprises a primary frame bottom section, a primary frame located on the side of the primary frame bottom section adjacent to the existing glass, a primary frame inner support section located on the side of the primary frame bottom section away from the existing glass, a glazing base disposed within the primary frame bottom section, the glazing base having glass setting block in contact with the edge of the vacuum glass, the primary frame having a glazing gasket strip groove on the side adjacent to the vacuum glass for mounting the glazing gasket strip, a glazing bead connection interspace disposed between the primary frame inner support section and the glazing base, the glazing bead connection interspace being detachably connected to a glazing bead, and the glazing bead having a sealing 2025234293   22 Sep 2025 gasket strip catch on its upper side facing the vacuum glass for connecting the second sealing gasket strip. Optionally, a glazing bead catch pocket extends from the bottom of the glazing bead connection interspace in a direction away from the primary frame inner support section, an upper catch tongue extends from the top end of the glazing bead catch pocket in a direction away from the primary frame, a glazing bead bottom tongue is provided on a lower side of the glazing bead and is configured to engage with the upper catch tongue, and a retention strip is provided at the end of the glazing bead bottom tongue for engagement with the glazing bead catch pocket. Optionally, the new retrofit glazing frame and the glazing bead are made of metal or polyvinyl chloride, the glass setting block is made of chloroprene rubber, the glazing gasket strip, and the second sealing gasket strip are made of ethylene propylene diene monomer or silicone, and the glazing gasket strip combines soft rubber strip which are made of polyethylene or ethylene propylene diene monomer, and hard rubber strip which are made of ethylene propylene diene monomer or silicone. Optionally, the first thermal insulation layer and the second thermal insulation layer are made of an inorganic aerogel composite material Optionally, the vacuum glass comprises a edge seal, and two glass sheets attached to opposite sides of the edge seal, a vacuum cavity is formed between the two glass sheets, one of the inner surfaces of the glass sheets is coated with a low-emissivity coating, a getter is disposed within the vacuum cavity, support pillars are arranged in the vacuum cavity, and the edges of the two glass sheets are bonded to edge seals by means of sealing adhesive. Optionally, the thickness of the glass sheets is 3-6 mm, the pressure within the vacuum cavity does not exceed 0.1 Pa, and the gap width of the vacuum cavity is between 0.15 mm and 0.3 mm. Optionally, the support pillars are made of metal or ceramic. Optionally, comprises a pressure-sensitive adhesive strips and a spacer, the spacer is made of metal, thermoplastic, foam, or composite material and the pressure-sensitive adhesive strips are on both sides, wherein the glazing spacer strip further contains a desiccant. Optionally, the desiccant is a molecular sieve or a mixture of silica gel and molecular sieve. Compared to the prior art, the present invention offers the following advantages: 2025234293   22 Sep 2025 1. The combination of vacuum glass, thermally insulated glazing frame and thermally insulated decorative cover significantly reduces the overall thermal transmittance of the system. Heat loss in winter can be reduced by 82%, while solar heat gain in summer is lowered by 73%, thereby decreasing heating and cooling loads. For example, for a window 5       area of 18.6 square meters, this results in an annual energy cost saving of approximately AUD 921 and a reduction of 4 tonnes of CO2 emissions, meeting the high-performance energy standards of Green Star, LEED, and Passive House. 2. The integration of a glazing spacer strip containing desiccant and the use of inorganic aerogel insulation blocks thermal bridging through the original frame and absorbs residual 10       moisture and long-term vapor ingress. This design prevents fogging, mold growth, and corrosion of the inner glass surfaces, eliminates indoor condensation in winter and outdoor heat penetration in summer, and significantly enhances thermal comfort. 3. The vacuum cavity and multilayer structure of the vacuum glass, thermally insulated glazing frame and thermally insulated decorative cover effectively block high-frequency 15       noise, achieving an acoustic performance improvement of over 40 dB(A), thereby reducing indoor noise pollution and supporting a quieter environment for urban buildings. 4. The system enables rapid installation without removing the existing enclosure frame, using pre-installed sealing strips, stainless steel self-drilling screws, and support pads. This reduces installation time and cost while avoiding construction waste. The use of recyclable, 20       environmentally friendly materials such as inorganic aerogel composites and EPDM / silicone sealing strips aligns with green building principles. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic view of the overall structure of the retrofit glazing system according to the present invention. 25 Figure 2 is a structural view of the thermally insulated glazing frame. Figure 3 is a structural view of the new retrofit glazing frame. Figure 4 is a structural view of the glazing bead. Figure 5 is a structural view of the glazing gasket strip. Figure 6 is a structural view of the glazing spacer strip. 30 Figure 7 is a structural view of the vacuum glass. Figure 8 is a structural view of the thermally insulated decorative cover. 2025234293   22 Sep 2025 Figure 9 is a structural view of the decorative cover. Figure 10 is a flowchart showing the installation process of the invention. Figure 11 is a comparative diagram showing the thermal simulation results of the invention. The reference numerals used in the drawings include: 1: existing enclosure frame; 2: existing 5 glass; 3: thermally insulated glazing frame; 31: new retrofit glazing frame; 32: first thermal insulation layer; 33: glazing gasket strip; 331: hard rubber strip; 332: soft rubber strip; 34: glazing spacer strip; 341: pressure-sensitive adhesive strips; 342: spacer; 35: corner connector; 36: glass setting block; 311: primary frame bottom section; 312: primary frame; 313: primary frame inner support section; 314: glazing gasket strip groove; 315: corner connector slot; 316: 10 glazing bead connection interspace; 317: glazing bead catch pocket; 318: upper catch tongue; 319: glazing base; 3110: setting block positioning holder; 3111: decorative cover slot; 4: glazing bead; 41: glazing bead bottom tongue; 42: retention strip; 43: support leg; 44: sealing gasket strip catch; 5: vacuum glass; 51: edge seal; 52 s glass sheet; 53 s vacuum cavity; 54 x getter; 55 x support pillar; 6: second sealing gasket strip; 7: thermally insulated decorative 15 cover; 71: decorative cover; 72: second thermal insulation layer; 711: panel; 712: decorative cover top end socket; 713: decorative cover bottom end socket; 8: decorative cover top end sealant; 9: decorative cover bottom end sealant; 10: fastener; DETAILED DESCRIPTION OF EMBODIMENTS The following provides a more detailed description of the retrofit glazing system proposed in 20 the present invention, with reference to the accompanying drawings and specific embodiments. Based on the description below, the advantages and features of the invention will become clearer. It should be noted that the drawings are presented in a simplified form and not to precise scale, and are provided solely for the purpose of clearly illustrating the embodiments of the invention. 25 The same or similar reference numerals in the drawings denote the same or similar components. Refer to Figure 1, a retrofit glazing system includes an existing enclosure frame (1) and existing glass (2) installed on the existing enclosure frame (1). The system further comprises: 1. Thermally Insulated Glazing Frame (3): Refer to Figure 2, the thermally insulated glazing frame (3) is fixed to the existing 30        enclosure frame (1) via fasteners (10). The left and bottom sides of the thermally insulated frame are tightly fitted against the interior surfaces of the existing glass (2) and existing 2025234293   22 Sep 2025 enclosure frame (1). The thermally insulated glazing frame (3) comprises a new retrofit glazing frame (31), a first thermal insulation layer (32), a glazing gasket strip (33), a glazing spacer strip (34), a corner connector (35), and a glass setting block (36), which are pre-assembled at the factory or on-site. 5        Refer to Figure 3, the new retrofit glazing frame (31) comprises: • a primary frame bottom section (311); • a primary frame (312) extending upward from one side of the primary frame bottom section (311); and • a primary frame inner support section (313) located on the side of the primary frame 10          bottom section (311) away from the existing glass (2). The inner side of the upper portion of the primary frame (312) is provided with a glazing gasket strip groove (314) to secure the glazing gasket strip (33). The lower portion includes a corner connector slot (315) for fixing the corner connector (35). A glazing bead connection interspace (316) is provided between the primary frame inner support section 15        (313) and the glazing base (319), and the bottom of the glazing bead connection interspace (316) has a glazing bead catch pocket (317), which extends upward to form an upper catch tongue (318). These are used to secure the glazing bead (4). A glazing base (319) is mounted above the primary frame bottom section (311), positioned closer to the interior. The glazing base (319) is provided with a setting block positioning holder (3110) for 20        securing the glass setting block (36). Below the primary frame inner support section (313), a decorative cover slot (3111) is arranged. Adhesive is applied to the outer surfaces of both the outer and primary frame bottom section (311) to secure the insulation layer. The new retrofit glazing frame (31) is primarily made of aluminum alloy or PVC. Refer to Figure 4, one side of the lower portion of the glazing bead (4) is equipped with a 25       glazing bead bottom tongue (41) matching the upper catch tongue (318), with a retention strip (42) at the end. The glazing bead bottom tongue (41) and retention strip (42) are inserted into the glazing bead catch pocket (317). The other side has a support leg (43) which contacts the inner surface of the primary frame inner support section (313). The upper portion of the glazing bead (4) is equipped with a sealing gasket strip catch (44) for 30        fixing the second sealing gasket strip (6). The bead is made of aluminum or PVC; the retention strip (42) is made of EPDM or silicone rubber. 2025234293   22 Sep 2025 The corner connector (35) is located between the inner side of the primary frame (312) and the corner connector slot (315), typically 50 mm in length. The connector connects individual frame components into a rectangular structure using known corner assembly techniques. 5        The glass setting block (36) is made of neoprene rubber and inserted into setting block positioning holders (3110) of the glazing base (319) at ¼ positions along its length, supporting the weight of the vacuum glass (5). A preferred size is 16 mm wide, 10 mm high, and 50 mm long, adjustable as needed. Fasteners (10) are stainless steel self-drilling screws. Inserted from the center of the 10        glazing base (319) downward, penetrating the base and the structural wall of the existing enclosure frame (1), at intervals of no less than 150 mm. Refer to Figure 5, the glazing gasket strip (33) is installed between the primary frame (312) and vacuum glass (5), fixed into the glazing gasket strip groove (314). Preferably a coextruded glazing gasket strip combining soft rubber strip (332) (e.g., polyethylene or 15       EPDM foam) and hard (e.g., EPDM or silicone) rubber strip (331). The hard rubber strip (331) anchors into the slot, while the soft rubber strip (332) part covers the top of the primary frame (312) to reduce thermal bridging. The sides of the second stealing strip contact the sealing gasket strip catch (44) and vacuum glass (5), fixed via friction. Made of EPDM or silicone. 20        The first thermal insulation layer (32) is located between the existing glass (2), existing enclosure frame (1), and new retrofit glazing frame (31). Secured to the outer surfaces of the outer and primary frame bottom section (311) via adhesive. Made of aerogel composite, featuring low thermal conductivity (< 0.02 W / m^K), hydrophobicity, flame resistance, durability, and flexibility. Thickness: 3-20 mm. 25        Refer to Figure 6, the glazing spacer strip (34) comprises a pressure-sensitive adhesive strips (341) and a spacer (342). The spacer (342) is made of metal, thermoplastic, foam, or composite material. The pressure-sensitive adhesive strips (341) are on both sides. During pre-assembly, one adhesive side is pressed to the outer side of the primary frame (312); the bottom contacts the first thermal insulation layer (32). On-site, the other 30        adhesive side is pressed to the existing glass (2). The glazing spacer strip is internally filled with desiccant (e.g., molecular sieve or silica gel / molecular sieve mix) to absorb moisture from the air cavity between the glasses and prevent fogging. Preferably compliant with EN ISO 10077 with £(dA) < 0.007 W / K. Dimensions: 5-40 mm wide, 3-12 mm high. 2025234293   22 Sep 2025 Refer to Figure 7, edges of the vacuum glass (5) extend at least 18 mm into the new retrofit glazing frame (31), bottom supported by the glass setting block (36), sides sealed by the glazing gasket strip (33) and the second sealing gasket strip (6). An enclosed air cavity is formed between the vacuum glass (5) and existing glass (2). Composed of two glass sheets 5        (52) joined by support pillars (55) (metal or ceramic), with a vacuum cavity (53) between them (pressure < 0.1 Pa, gap 0.15-0.3 mm). One of the glass sheets (52) is coated with a low-emissivity coating. Overall thickness: 6-13 mm. The gap of the two glass sheets (52) at the edge is sealed with edge seal (51) using solder glass or metal, and a getter (54) is placed inside to maintain vacuum long-term. 10   2. Thermally Insulated Decorative Cover (7): Refer to Figure 8, the thermally insulated decorative cover (7) covers the visible interior portion of the existing enclosure frame (1), enhancing aesthetics. Composed of a decorative cover (71) and a second thermal insulation layer (72), pre-assembled in the factory or on-site. 15   3. Decorative Cover (71) (see Figure 9): Refer to Figure 9, the decorative cover (71) includes an L-shaped panel (711), along with a decorative cover top end socket (712), and a decorative cover bottom end socket (713) located at either end of the panel (711). The decorative cover top end socket (712) is located at the top left corner of the decorative cover (71) and inserts into the decorative 20        cover slot (3111) and is sealed with the decorative cover top end sealant (8). The decorative cover bottom end socket (713) seals to the interior finish surface with a decorative cover bottom end sealant (9). The panel (711) is positioned between the decorative cover top end socket (712) and the decorative cover bottom end socket (713). The inner surface of the panel (711) is coated with adhesive for attaching the second 25        thermal insulation layer (72). Preferred materials of the panel (711) are PVC or metal. The Second Thermal Insulation Layer (72) is located between panel (711) and existing enclosure frame (1), made of the same aerogel composite as first thermal insulation layer (32), and is fixed to the decorative cover (71) by an adhesive applied to the inner surface of the panel (711). 30        The decorative cover top end sealant (8) seals the joint between decorative cover top end socket (712) and decorative cover slot (3111), made of silicone or polyurethane. The decorative cover bottom end sealant (9) seals the joint between decorative cover bottom end socket (713) and interior finish, also made of silicone. 2025234293   22 Sep 2025 Refer to Figure 10, the installation process of the invention comprises: 1. Step 1: Fix the prefabricated thermally insulated glazing frame (3) to the existing enclosure frame (1) using fasteners (10), ensuring tight contact on left and bottom sides. 2. Step 2: Insert vacuum glass (5) into the new retrofit glazing frame (31), fix the glazing 5          bead (4), and insert the second sealing gasket strip (6) between the bead and glazing. 3. Step 3: Insert one end of the thermally insulated decorative cover (7) into the frame and seal with decorative cover top end sealant (8); seal the other end of the thermally insulated decorative cover (7) to the wall with the decorative cover bottom end sealant (9). 10 Figure 11 shows the performance results of this system. This system improves the energy efficiency of overall glazing system, reducing heat loss by 82% in winter and solar heat gain by 73% in summer. For a 18.6 m2 window, annual energy savings are estimated at AUD 921 and a reduction of 4 tonnes of CO2 emissions. This yields a high return on investment (ROI) and meets Australian Green Star, LEED, and Passive House standards. 15 The above is a preferred embodiment and does not limit the scope of the invention. Variations and modifications by those skilled in the art, based on this disclosure, fall within the scope of the appended claims.

Claims

EDITORIALNOTEThe following claim pages are numbered 1 to 3 instead of 10 to 12.2025234293   02 Oct 2026WHAT ARE CLAIMED:

1. A retrofit glazing system comprising an existing enclosure frame (1) and an existing glass (2) mounted to the existing enclosure frame (1), wherein the retrofit glazing system further comprises: 5 a thermally insulated decorative cover (7) connected to the indoor-facing side of the existing enclosure frame (1); a new retrofit glazing frame (31) connected to the interior side of the existing enclosure frame (1) and joined to the thermally insulated decorative cover (7); a first thermal insulation layer (32) disposed between the new retrofit glazing frame (31), 10 the existing enclosure frame (1), and the existing glass (2); a second thermal insulation layer (72) disposed between a decorative cover (71) and the existing enclosure frame (1); a vacuum glass (5) mounted within the new retrofit glazing frame (31), forming an air cavity between the vacuum glass (5) and the existing glass (2), with a glazing gasket strip 15 (33) and a second sealing gasket strip (6) respectively disposed between each side of the vacuum glass (5) and the new retrofit glazing frame (31); and a glazing spacer strip (34) disposed within the air cavity, having opposite sides in contact with the existing glass (2) and the vacuum glass (5), and a lower side in contact with the new retrofit glazing frame (31) and the first thermal insulation layer (32), 20 wherein the new retrofit glazing frame (31) comprises: a primary frame bottom section (311); a primary frame (312) located on the side of the primary frame bottom section (311) adjacent to the existing glass (2); a primary frame inner support section (313) located on the side of the primary frame 25 bottom section (311) away from the existing glass (2); a glazing base (319) disposed within the primary frame bottom section (311), the glazing base (319) having glass setting block (36) in contact with the edge of the vacuum glass (5);2025234293   02 Oct 2026the primary frame (312) having a glazing gasket strip groove (314) on the side adjacent to the vacuum glass (5) for mounting the glazing gasket strip (33);a glazing bead connection interspace (316) disposed between the primary frame inner support section (313) and the glazing base (319) , the glazing bead connection interspace5         (316) being detachably connected to a glazing bead (4); andthe glazing bead (4) having a sealing gasket strip catch (44) on its upper side facing the vacuum glass (5) for connecting the second sealing gasket strip (6).

2. The retrofit glazing system of claim 1, wherein a glazing bead catch pocket (317) extends from the bottom of the glazing bead connection interspace (316) in a direction away from10         the primary frame inner support section (313), an upper catch tongue (318) extends fromthe top end of the glazing bead catch pocket (317) in a direction away from the primary frame (312);a glazing bead bottom tongue (41) is provided on a lower side of the glazing bead (4) and is configured to engage with the upper catch tongue (318); and15         a retention strip (42) is provided at the end of the glazing bead bottom tongue (41) forengagement with the glazing bead catch pocket (317).

3. The retrofit glazing system of claim 2, wherein the new retrofit glazing frame (31) and the glazing bead (4) are made of metal or polyvinyl chloride;the glass setting block (36) is made of chloroprene rubber;20         the glazing gasket strip (33), the second sealing gasket strip (6) are made of ethylenepropylene diene monomer or silicone; andthe glazing gasket strip combines soft rubber strip (332) which are made of polyethylene or ethylene propylene diene monomer, and hard rubber strip (331) which are made of ethylene propylene diene monomer or silicone.25   4. The retrofit glazing system of claim 1, wherein the first thermal insulation layer (32) andthe second thermal insulation layer (72) are made of an inorganic aerogel composite material.

5. The retrofit glazing system of claim 1, wherein the vacuum glass (5) comprises an edge seal (51), and two glass sheets (52) attached to opposite sides of the edge seal (51), a30         vacuum cavity (53) is formed between the two glass sheets (52), one of the inner surfaces2025234293   02 Oct 2026of the glass sheets (52) is coated with a low-emissivity coating, a getter (54) is disposed within the vacuum cavity (53), support pillars (55) are arranged in the vacuum cavity (53), and the edges of the two glass sheets (52) are bonded to the edge seal (51) by means of sealing adhesive.5   6. The retrofit glazing system of claim 5, wherein the thickness of each of the glass sheets(52) is 3-6 mm, the pressure within the vacuum cavity (53) is not more than 0.1 Pa, and the gap width of the vacuum cavity (53) is between 0.15 mm and 0.3 mm.

7. The retrofit glazing system of claim 5, wherein the support pillars (55) are made of metal or ceramic.10   8. The retrofit glazing system of claim 1, wherein the glazing spacer strip (34) comprisespressure-sensitive adhesive strips (341) and a spacer (342), the spacer (342) is made of metal, thermoplastic, foam, or composite material and the pressure-sensitive adhesive strips (341) are on both sides, wherein the glazing spacer strip (34) further contains a desiccant.15   9. The retrofit glazing system of claim 8, wherein the desiccant is a molecular sieve or amixture of silica gel and molecular sieve.

Images