MARTIN, Alan (39 Dunure Road, Doonfoot, Ayr KA7 4HR, GB)
ROBERTS, Stephen, Mark (Craigowan, Brewlands Road, Symington KA1 5QY, GB)
MARTIN, Alan (39 Dunure Road, Doonfoot, Ayr KA7 4HR, GB)
| CLAIMS A glazing unit comprising: (i) first and second panes of glazing material, each pane of glazing material defining first and second major surfaces, each major surface defining an outer perimeter, and an at least one peripheral surface between said major surfaces; (ii) on each pane of glazing material, first and second seals mounted on said first and second major surfaces respectively adjacent and extending along said outer perimeter; (iii) a frame having opposed first and second outwardly facing surfaces and defining a periphery of said glazing unit and having extending from it a spacer bar having first and second opposed outwardly facing surfaces, said first and second panes of glazing material being mounted upon said frame with said first major surfaces facing inwards arranged facing one another; (iv) at least one compression cap mounted on each of said frame first and second outwardly facing surfaces and overlapping said panes of glazing material and said second seals on said second major surface of said panes of glazing material. 2. A glazing unit according to claim 1 , wherein in at least one pair of: (a) said spacer bar outwardly facing surface, and (b) said first seal mounted on said first major surface of said corresponding pane of glazing material, one of said spacer bar outwardly facing surface and said first seal comprises holding means to hold the other. 3. A glazing unit according to claim 2, wherein said holding means comprises a protrusion extending from the one into a complementary recess defined in the other. 4. A glazing unit according to claim 3, wherein said protrusion is engaged with said recess. 5. A glazing unit according to claim 3 or 4, wherein said protrusion extends from said first seal, and said recess is defined in said spacer bar outwardly facing surface. 6. A glazing unit according to any of claims 2-5, wherein in each pair of: (a) said spacer bar outwardly facing surface, and (b) said first seal mounted on said first major surface of said corresponding pane of glazing material, one of said spacer bar outwardly facing surface and said first seal comprises holding means to hold the other. 7. A glazing unit according to any of the preceding claims, wherein at least one of said spacer bar first and second opposed outwardly facing surfaces additionally defines at least one tooth or ridge. 8. A glazing unit according to any of the preceding claims, wherein the portion of said at least one compression cap which overlaps said second seal on said second major surface of at least one of said first and second panes of glazing material comprises at least one tooth or ridge. 9. A glazing unit according to any of the preceding claims, wherein at least one compression cap comprises a cap, compression means, and a seal between said cap and said compression means. 10. A glazing unit according to claim 9, said at least one cap additionally comprises cover means which mates or otherwise engages with said cover means. 11 . A glazing unit according to any of the preceding claims, wherein said frame and at least one said compression cap comprise complementary positioning means. 12. A glazing unit according to any of the preceding claims, wherein at least one pane of glazing material is glass. 13. A glazing unit according to any of the preceding claims, additionally comprising a blind between said first and second panes of glazing material. 14. A glazing unit according to any of the preceding claims, additionally comprising securing means to secure said glazing unit to an external surface. 15. A room comprising an at least one glazing unit according to any of the preceding claims, a floor underneath said at least one glazing unit, and a ceiling. |
The present invention is concerned with improved glazing units and constructions (particularly rooms) and enclosures incorporating same. In particular, the present invention seeks to provide modular positive- and negative-pressure capable glazing units which provide for simple and convenient assembly, disassembly and maintenance.
Pressure sealed rooms, particularly positive pressure rooms, are widely used in the health care sector, for example intensive care unit (ICU), isolation unit (ISU), critical care unit (CCU) and high dependency unit (HDU) rooms. Pressure sealed rooms are also widely used in laboratory and production environments, for example positive pressure cleanrooms. Examples of negative pressure rooms include airborne isolation rooms (AIRs), also referred to as airborne infection isolation rooms (AIIRs). An AMR is a single-patient room that is equipped with special air handling and ventilation capacity. In some cases, AIIRs may meet the American Institute of Architects/Facility Guidelines Institute (AIA FGI) standards for AIIRs (i.e., monitored negative pressure relative to the surrounding area, 12 air exchanges per hour for new construction and renovation and 6 air exchanges per hour for existing facilities, air exhausted directly to the outside or recirculated through HEPA filtration before return) (AIA, Guidelines for Design and Construction of Hospital and Health Care Facilities, In: American Institute of Architects, Washington, DC: American Institute of Architects Press, 2006; CDC, Guidelines for Environmental Infection Control in Health-Care Facilities, Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC), MMWR 2003, 52(RR10): 1 -42). In other cases, AIIRs do not and are not required to meet those standards. Glass walled hospital rooms have been well known for more than a century (see e.g. GB191009357), the glass providing easy viewing of the room interior and a surface which is relatively easy and convenient to clean. However, such glass walled rooms are not necessarily pressure sealed rooms. Furthermore, glass-walled pressure sealed rooms, particularly pressure sealed rooms the surface of whose walls primarily consist of glass, are not conventionally available, and not as an off-the-shelf product. Despite this, current pressure sealed rooms such as ICU, ISU, CCU and HDU hospital rooms and AIIRs are typically constructed using conventional building techniques e.g. from timber framing and plasterboard, and are provided with a small viewing window. This itself is problematic - patients in such rooms are typically in poor health and vulnerable, and many accidents and resulting deaths occur due to patients falling and this going un-noticed by staff who cannot see their movements.
Such rooms are difficult to clean to an acceptable level for hospital care environments and a study (Goodman ER et al., Infect Control Hosp Epidemiol. 2008 Jul; 29(7): 593-9; P ID: 18624666) has shown that after standard cleaning of surfaces in conventional ICU rooms, 45% of samples resulted in environmental cultures positive for MRSA or VRE, and concluded that broad flat surfaces were most likely to be cleaned. This is indicative of issues encountered with materials used in fabricating the ICU rooms which harbour bacteria and viruses, and the construction practices which result in so called "dirt traps" where dirt (and thus micro-organisms) collects.
Although enhanced education, training and testing can result in improved cleaning and reduced frequency of RSA/VRE contamination, this only reduced the 45% figure to 27%, indicating that a substantial problem remains.
Sexton T et al. (J Hosp Infect. 2006 Feb; 62(2): 187-94; PMID: 16290319) report that conventional isolation rooms of MRSA patients are subject to high levels of MRSA contamination even after cleaning and that they are only cleaned to 34% (i.e. 66% of samples result in cultures positive for MRSA).
Recent advances in medical device sterilisation have included the use of gas plasma hydrogen peroxide sterilisation/cleaning, also known as hydrogen peroxide vapour (HPV) cleaning, and which is found to be highly effective (French GL et al., J Hosp Infect. 2004 May;57(1 ):31 -7; PMID: 15142713). However, this is only suitable for certain materials and in particular is not suitable for materials which absorb the mist and/or are corroded by it. Traditionally constructed isolation rooms, particularly hospital isolation rooms, are constructed from numerous materials which are not suitable for cleaning by gas plasma hydrogen peroxide sterilisation - the mist condenses on surfaces in the rooms and is absorbed and/or causes corrosion. It is therefore necessary to remove the condensed mist by wiping the surfaces dry, and this wiping process can actually introduce further contaminants. Thus, although the use of gas plasma hydrogen peroxide sterilisation of entire rooms such as isolation rooms is extremely desirable, current commercially available isolation rooms are not particularly compatible with it.
There is an increasing need to provide enhanced cleanliness within such rooms, and thus there is a strong desire for rooms, fabrication technique and materials which improve upon the existing rooms and which themselves are easier and more convenient to clean in order to e.g. reduce bacterial and viral contamination.
Furthermore, there is a need to provide for privacy within glass-walled pressure- sealed rooms without impacting negatively upon the cleanliness or ease of cleaning of the rooms.
Furthermore, there is a need to provide for the convenient maintenance of glazing units for example in the event of damage to glass panes on either the interior or exterior of the unit. This is of critical importance since failure of a pane of glazing material, of sealing of a pane of glazing material, or of anything contained between panes of glazing material e.g. a blind, can result in an entire room becoming out of order and unusable whilst it is fixed - a very costly and inconvenient situation.
There is also a strong desire and need for rooms which can be operated as both positive pressure and negative pressure rooms, i.e. can switch between the two.
It is therefore extremely desirable to provide means and apparatus for, and rooms themselves, which improve upon the prior art. The present invention seeks to overcome the prior art disadvantages.
According to a first aspect of the present invention there is provided a glazing unit comprising:
(i) first and second panes of glazing material, each pane of glazing material defining first and second major surfaces, each major surface defining an outer perimeter, and an at least one peripheral surface between said major surfaces;
on each pane of glazing material, first and second seals mounted on said first and second major surfaces respectively adjacent and extending along said outer perimeter;
a frame having opposed first and second outwardly facing surfaces and defining a periphery of said glazing unit and having extending from it a spacer bar having first and second opposed outwardly facing surfaces, said first and second panes of glazing material being mounted upon said frame with said first major surfaces facing inwards arranged facing one another;
at least one compression cap mounted on each of said frame first and second outwardly facing surfaces and overlapping said panes of glazing material and said second seals on said second major surface of said panes of glazing material.
As used herein, and unless the context dictates otherwise, the terms "inwards", "inwardly", "outwards" and "outwardly" define directions relative to a plane through the centre of the glazing unit, i.e. between the first and second panes of glazing material. Thus, each pane of glazing material has an inwardly facing surface and an outwardly facing surface. The inwardly facing surfaces of the first and second panes of glazing material (the first major surfaces) face one another, i.e. are opposed, whereas the outwardly facing surfaces (the second major surfaces) face away from one another.
Thus, the first and second panes of glazing material mounted upon the frame define (from the outermost surface to the innermost surface, with reference to the future orientation of the glazing unit once installed) an outwards facing surface of said first pane (herein "S1 "), an inwards facing surface of said first pane (herein "S2"), an inwards facing surface of said second pane (herein "S3"), and an outwards facing surface of said second pane (herein "S4"). Thus, surfaces S1 and S4 are the second major surfaces of the first and second panes of glazing material respectively, and surfaces S2 and S3 are the first major surfaces of the first and second panes of glazing material respectively. As well as defining first and second major surfaces, each pane of glazing material defines an at least one peripheral surface (minor surface). Typically, panes are rectangular in shape, thus defining four peripheral surfaces and four peripheral edges to each major surface.
Preferably, the frame is metallic. Preferably, the frame comprises aluminium, more preferably extruded aluminium. Preferably, the aluminium/extruded aluminium is powder coated.
Preferably, the spacer bar extends from the frame in a direction generally in a plane through the centre of the glazing unit.
In preferred embodiments of the present invention, the glazing material and frame are substantially, preferably at least 90, 95, 96, 97, 98 or 99%, more preferably
100%, resistant to corrosion caused by gas plasma hydrogen peroxide cleaning.
Preferably, the resistance to corrosion is over a given number of cleaning cycles, for example at least 50, 100, 150, 200, 250, 300, 400, 500, 750 or 1000. Preferably, the glazing material and frame do not need to be wiped dry after gas plasma hydrogen peroxide cleaning. Preferably the condensed mist rapidly evaporates from the surfaces during cleaning. In such embodiments, preferably the glazing material is glass and the frame is aluminium.
Preferably, the at least one compression cap and cover are metallic. Preferably, the at least one compression cap comprises aluminium, more preferably extruded aluminium. Preferably, the extruded aluminium is powder coated.
The first and second seals are preferably provided as discrete (i.e. separate) seals. Preferably, each first and second seal is a single piece. However, for convenient and simple manufacturing, if may be appropriate to form them from multiple components which are then joined together for example by welding. Preferably, each first and second seal is formed from four tape seals which are then supplemented by four injection-moulded corner pieces. The corner pieces are injection welded to the tape seals to give a single continuous seal. In some embodiments, the first and second seals may be provided in the form of a single combined seal having a U-shaped cross-section. Other arrangements of seals falling within the scope of the present invention will be readily apparent to the skilled person. Preferable seals are non-ceramic seals, more preferably non-ceramic tape seals. More preferably, seals are silicon seals, more preferably having a Shore A % value of 35±5.
In certain embodiments (for example for fire-rated products), seals may be ceramic seals such as ceramic tape seals.
Preferably, in at least one pair of:
(a) a spacer bar outwardly facing surface, and
(b) a first seal mounted on said first major surface of said corresponding pane of glazing material,
one of them comprises holding means to hold the other.
Preferably, the holding means of the one bites, mates with or engages the other. Preferably, the holding means comprises a protrusion extending from the one into a complementary recess defined in the other. Preferably, the protrusion is engaged with the recess.
Preferably, the protrusion extends from the first seal, and the recess is defined in the spacer bar outwardly facing surface.
Preferably, the protrusion is in the form of a rib. Preferably, the protrusion, particularly the rib, comprises a neck and a head. Thus, the protrusion from the first seal mates with and engages the recess. Thus, the protrusions from the first seal can be considered to be a male member, and the spacer bar recess to be a female member. Preferably, the holding means extend along most of the length of the first seal, for example along at least 70, 80, 90 or 95% of the length of the first seal.
Preferably, in each pair of:
(a) a spacer bar outwardly facing surface, and
(b) a first seal mounted on the first major surface of the corresponding pane of glazing material,
one of them comprises holding means to hold the other.
Thus, in preferred embodiments the first seals have a protrusion extending from them into and engaged in corresponding recesses in the spacer bar outwardly facing surfaces.
When a glazing unit of the present invention is being assembled using first seals having protrusions and a frame with a spacer bar with recesses in the outwardly facing surfaces, the first seals are preferably located prior to the glass being put in place, i.e. the protrusions of the first seals are engaged with the recesses of the spacer bar. This allows correctly dimensioned first seals to be correctly located against the spacer bar without any need to position the panes of glazing material, enhancing the convenience of assembly.
Preferably, the frame portion from which the spacer bar extends is generally perpendicular to the spacer bar. In an assembled glazing unit, that frame portion in lower parts of the frame bears the weight of the panes of glazing material. Preferably, that frame portion is provided with cushioning. Suitable examples include a non- ceramic seal material such as a tape seal, such as a silicone tape seal. That acts to provide cushioning when the pane of glazing material is positioned in the frame and can also assist in providing further sealing. When glazing units of the present invention are assembled from their component parts, the frame is usually assembled first so as to ensure that it correctly fits the space into which it is being placed. With the frame assembled in a given space, the first seals are inserted and engaged with the spacer bar recesses and cushioning installed on the lower surfaces of the frame generally perpendicular to the spacer bar outwardly facing surfaces and which will bear the weight of the panes of glazing material. The glazing material can then be placed in position with the first seals already correctly in position. Inevitably, it is extremely difficult and costly to have precisely cut pieces of glazing material - there is almost always a small variance in size between what is desired and what is actually cut. The glazing units of the present invention are tolerant to such variances in size of the panes of glazing material. With the panes of glazing material in place, the second seals can then be applied and the compression caps put in position and the compression means used to exert a compressive force exerted between the body of the compression caps and the frame upon the first and second seals and the pane of glazing material, effecting a seal.
Disassembly of a glazing unit for maintenance is equally simple and convenient. The holding means, particularly in the case of a protrusion engaged in a recess, can assist during disassembly by resisting movement of the panes of glazing material caused by pressure differential across the panes of glazing material. Typically, removal of a single pane of glazing material in a glazing unit (for example to allow for its replacement or cleaning, or maintenance of a blind located between the first and second panes of glazing material) can be done without depressurising the pressure- sealed room which it forms part of.
This is fundamentally different to glazing units conventionally used in pressure sealed rooms, which glazing units are permanently sealed and not designed for in situ maintenance - recent maintenance by the present inventors of glazing units in a newly built intensive care room where the blinds located between the panes of glazing material had failed required that the intensive care room was decommissioned whilst individual glazing units were removed, taken off-site, taken apart, the blinds fixed, the glazing units rebuilt, tested, returned to site and the intensive care room re-assembled. The total cost for repairing an otherwise minor fault in blinds is estimated at about GBP15000. Repairing an equivalent fault in blinds in glazing units of the present invention could be done in situ, would not require the pressure-sealed room to be decommissioned and would require a tiny fraction of the time and resources. Importantly, repairs to glazing units of the present invention can be done without requiring a patient to be moved from the pressure-sealed room which the glazing unit forms part of.
The at least one compression cap overlaps the second seal. Thus, with an at least one compression cap mounted upon a frame outwardly facing surface and overlapping a pane of glazing material (and the second seal extending over it), compressive force is exerted by the compression cap between it and the frame upon the second seal, the pane of glazing material, and the first seal, thus allowing an excellent seal to be achieved. Preferably, at least one of the spacer bar first and second opposed outwardly facing surfaces defines at least one additional holding means, more preferably at least one tooth or ridge. Preferably, each spacer bar first and second opposed outwardly facing surface defines at least one additional tooth or ridge. Preferably, the portion of the at least one compression cap which overlaps the second seal comprises at least one holding means, more preferably at least one tooth or ridge.
Such teeth and ridges need not engage in complementary recesses in the first and second seals, but rather exert points of pressure upon the first and second seals to assist in effecting a gas-tight seal by biting into them.
Preferably, the at least one compression cap comprises a plurality of compression caps located along the length of each of the outwardly facing surfaces of the frame. In the case of panes of glazing material (e.g. rectangular glazing panes) having major surfaces defining a periphery with a plurality of edges, compression caps are preferably provided at each corner (i.e. at each intersection of edges of the periphery), as well as along the edges between the corners i.e. along the periphery between the intersections of the edges. Preferably, at least one, preferably each, compression cap comprises a body and compression means such as a rod having a head on it, arranged such that the head exerts compressive force upon the body and thus upon the glazing pane thereunder. Examples of rods and heads are screws, and nuts and bolts.
Preferably, each at least one compression cap comprise a single compression means. For example, a compression cap may comprise a generally circular body (when viewed face-on, i.e. perpendicular to a longitudinal axis defined by the compression means) and a single compression means e.g. screw, or nut and bolt. Other shapes of body are of course possible and indeed as shown in the embodiments below there are many embodiments in which generally non-circular (for example, semi-circular) shapes are appropriate. Alternatively, a compression cap body may be provided in the form of an elongate strip. Preferably, such strips are provided with a plurality of compression means so as to exert compressive force along the length of the strips.
Preferably, the body of the at least one compression cap defines an orifice or slot through which each compression means (for example a screw, bolt or other member) passes. Thus, an orifice or slot may define a longitudinal axis in an at least one compression cap body. Alternatively, an at least one compression cap body may be provided without an orifice or slot for the compression means to pass through. In such cases, the compression cap body is preferably provided with an indent (or a plurality of indents if an elongate compression cap body is provided for use with a plurality of compression means), and the compression means preferably comprises a self-tapping screw.
Thus, in the case of compression means comprising a screw, the shank of the screw passes through the compression cap body (preferably through an orifice in the compression cap body) and into the frame (preferably into a suitably dimensioned orifice in the frame) and is screwed in so as to effect a friction fit with the frame. Preferably, a seal is provided between the compression cap body and each compression means for example in the form of a washer such as a washer seal such as a hermetic washer seal. Preferably, the seal acts to reduce or minimise fluid flow, e.g. gas flow. Thus, the compression means (for example the head of a screw) exerts compressive force upon the compression cap body and the seal.
Preferably, a cover is provided which mates or otherwise engages with each compression cap body so as to present a generally smooth external surface to the compression cap body and thus enable convenient cleaning and reduce the opportunity for dirt or microbes to be retained in the compression cap.
Preferably, each cover is fabricated from the same material as the compression cap body with which it is engaged. Thus, preferably the compression cap body defines a threaded recess through which is defined an orifice to permit passage of the rod or shank of the compression means. A seal is placed in the recess, and a screw placed in the recess such that it projects through the orifice. The screw is then turned so as to engage with or define an orifice in the frame and effect a friction fit. The screw is tightened until sufficient compressive force is exerted upon the compression cap body and the seal located in the recess. A suitable pressure may be pre-defined and a torque screwdriver or suchlike used to tighten the screw until the desired force is exerted. A threaded cover is then screwed into place in the threaded recess so as to provide a generally smooth surface to the compression cap body, permitting easy cleaning.
Preferably, an at least one pressure seal is provided between the frame and each cap.
Pressure seals are preferably in the form of a seal member located in a recess in the surface of the frame, from which the seal member projects, and which is compressed by the compression cap to effect a seal.
For example, this may be in the form of a pressure seal strip located in and protruding from a recess defined in the frame first and second outwardly facing surfaces and which is compressed by contact with the compression cap to provide an enhanced seal.
Alternatively or in addition, a pressure seal may be provided in the form of a pressure seal strip located in and protruding from a recess in the compression cap and which is compressed by contact with the frame to provide an enhanced seal.
Preferably, one or both panes of glazing material are panes of glass, being identical or non-identical panes.
Preferably, the panes of glass are independently selected from the group consisting of: laminated glass and toughened glass. The glass may be patterned and/or it may be annealed, heat-treated, heat-strengthened (semi-tempered) or toughened (fully tempered). Furthermore, the glass may bear a coating, e.g. a self-cleaning coating or some other functional coating. For example, the glass may bear an anti-microbial coating. Preferably, the glass bears a silver nitrate anti-microbial coating.
A laminate may be a glass laminate, having two or more panes of glass joined together by a laminating interlayer material, or a non-ceramic laminate, e.g. made of a wood-product.
In certain embodiments, the glazing material is coloured or otherwise tinted. Preferably, at least one pane of glazing material is electrochromic. Preferably, the glazing unit comprises control means for same.
Typically the panes of glazing material may be of a thickness between 8mm and 16mm. Preferably, one pane of glass has a thickness of about 8.8mm and the other has a thickness of about 12.8mm. Preferably, one pane of glazing material is between 20 and 50% thicker than the other, more preferably between 25 and 40% thicker than the other, more preferably about 30% thicker than the other. For example, with panes of glass, one pane of glass may have a thickness of about 16.8mm and the other a thickness of about 12.8mm (i.e. the one pane is about 31.25% thicker the other). Tests for noise reduction (sound attenuation) achieved using such panes of glazing material, particularly panes of glass, are detailed below. The results show that a substantial advantage is achieved, and is greater than that achieved using panes of glazing material of equal thickness.
In certain embodiments incorporating fire rated glazing material such as fire rated glass, example thicknesses of panes of glass are. Suitable glasses include Pilkington Pyrostop (RTM) (15mm) (Pilkington Group Limited, St Helens, UK) and St Gobain (SGG) Swissflam (RTM) 30-N2 (16mm) (Vetrotech Saint-Gobain UK Ltd, Bradford, UK).
Preferably, in embodiments incorporating fire rated panes of glazing material, glazing liners such as stainless steel glazing liners are provided for the first pane of glazing material between the first seal and the spacer bar first outward facing surfaces, and between (i) the compression cap body and (ii) the frame and the second seal. Thus, overall the first and second seals are surrounded by the glazing liner.
For example, in one embodiment (not shown) a first pane of glazing material comprises 10mm thick Pyroswiss fire resistant glass, and a second pane of glass comprises 13mm thick toughened glass, and stainless steel glazing liners are provided for the first pane of glazing material between the first seal and the frame, and between the compression cap body and (i) the frame and (ii) the second seal. In this embodiment, the second seal between the compression cap body and the fire resistant glass is a ceramic tape seal. An additional seal is provided along the minor surfaces defined between the first and second major surfaces of each pane of glass, and that is separated from the frame by the stainless steel glazing liner.
Preferably, a blind is provided between the first and second panes of glazing material. Preferably, the blind is remotely operated, for example an electrically operated blind.
Preferably, the frame is secured to an external surface such as a wall by way of securing means, for example a screw or screws. Preferably, the securing means pass into and through the frame into the externa! surface. For example, a screw may be screwed into and through a spacer bar (i.e. into a surface between the first and second opposed outwardly facing surfaces), through the frame and into a wall. Preferably, a hermetic washer seal is provided between the securing means and the frame, more preferably between the securing means and the spacer bar, to reduce/minimise air flow through the resulting orifices in the frame into the volume defined between the first and second panes of glazing material and the frame. Preferably, a recess is provided in the spacer bar to receive the securing means. Preferably, cover means is provided which mates or otherwise engages with the recess in the spacer bar.
Also provided according to the present invention is a method of assembling a glazing unit according to the present invention, comprising the steps of:
(i) assembling a frame as defined herein;
(ii) positioning the first seals against the spacer bar first and second outwardly facing surfaces,
(iii) placing the first major surface of the first and second panes of glazing material against the first seals,
(iv) placing the second seals against the second major surface of the first and second panes of glazing material, and
(v) mounting the at least one compression cap on the frame overlapping the panes of glazing material and the second seals.
Also provided according to the present invention is a room comprising an at least one glazing unit according to the present invention, a floor underneath said at least one glazing unit, and a ceiling.
Preferably, the room additionally comprises at least one wall. Preferably, the room additionally comprises at least one door.
Preferably, the room additionally comprises a floor covering which is mated or engaged with or between said frame and an at least one compression cap. Preferably, the floor covering is engaged between said frame and an at least one cap. Preferably, the floor covering is substantially gas impermeable. Preferably, the room has an air permeability rate at 55 Pa of <= 0.5 m 3 /hr.m 2 , more preferably <= 0.45 m 3 /hr.m 2 , more preferably <= 0.43 m 3 /hr.m 2 Preferably, the room is a pressure sealed room.
Preferably, the room additionally comprises ventilation means. More preferably, the room additionally comprises heating, refrigeration and/or air-conditioning means. Ventilation means are well known in the art and will be readily apparent to one of ordinary skill. Ventilation means may include an air inlet and an air outlet. Ventilation means may additionally comprise filtration means such as a HEPA filter.
Also provided according to the present invention is a method of ventilating a room according to the present invention including ventilation means, particularly a pressure sealed room, the method comprising operating the ventilation means.
The invention will be further apparent from the following description with reference to the several drawings of the accompanying figures which show by way of example only forms of glazing units and rooms. Of the Figures:
Figure 1 shows a perspective view of a room 100;
Figure 2 shows a top plan view of a room 100;
Figure 3 shows a front elevation of room 100;
Figure 4 shows a rear elevation of room 100;
Figure 5 shows a side elevation of room 100;
Figure 6 shows section A-A shown in Figure 2;
Figure 7 shows section B-B shown in Figure 2;
Figure 8 shows section C-C shown in Figure 2;
Figure 9 is an enlarged view of Detail 1 shown in Figure 2;
Figure 10 is an enlarged view of Detail 2 shown in Figure 2;
Figure 1 1 is an enlarged view of Detail 3 shown in Figure 2;
Figure 12 is an enlarged view of Detail 4 shown in Figure 2;
Figure 13 is an enlarged view of Detail 5 shown in Figure 6;
Figure 14 is an enlarged view of Detail 6 shown in Figure 6;
Figure 15 is an enlarged view of Detail 7 shown in Figures 6, 7, 8; Figure 16 is an enlarged view of Detail 8 shown in Figure 7;
Figure 17 is an enlarged view of Detail 9 shown in Figure 8;
Figure 18 is a top plan view of a test pressure sealed room; and
Figure 19 shows a close-up view of a spacer bar.
A summary of the reference signs used herein is given at the end of the description immediately prior to the claims. All "PMID" references are PubMed accession numbers (www.ncbi.nlm.nih.gov). Experiments have shown that the glazing units of the present invention are particularly advantageous. As detailed below:
(i) they are simple and easy to clean to a high standard;
(ii) they effect a high quality pressure seal
(iii) in the event that one of the panes of glazing material is broken, the other will retain the pressure seal - experiments have shown that a single 10mm pane of glazing material can achieve an air permeability rate at 55Pa of < 0.43 m 3 /hr.m 2
(iv) individual panes of glazing material of the glazing units can be readily removed and replaced without having to remove and replace the entire glazing unit. Thus, in situ repairs can be readily performed meaning that the room does not have to be evacuated in the event of a pane of glazing material failing.
As shown in Figure 1 , the external perimeter of pressure sealed room 100 comprises a plurality of glazing units 1 10, hermetically sealing automatically sliding door 1 15 (model SLX-D, Kaba Gilgen AG, Switzerland; www.kaba.com), floor 120 and ceiling 130. Glazing units 140 and hermetically sealing automatically sliding door 150 (model SLX-D) define outer ("airlock lobby") and inner ("patient room") regions 160, 170 respectively of room 100.
Individual glazing units 110, 140 comprise a frame F in the form of corner posts 1 , T- posts 2, floor channels 3, door posts 4, mullions 5, ceiling channels 6 and transoms 7. As can be seen from Figure 9, powder coated aluminium corner post 1 has first and second spacer bars 180 extending inwardly from it into glazing unit volume 111 . Each spacer bar 180 has first and second opposed outwardly facing surfaces 190, 200.
Each first seal 25 is a 12mm wide 1 mm deep Shore A % 35 silicone tape seal and has a protrusion (i.e. a male member) 220 extending therefrom having a neck and a head portion which is push-fitted into recess 191 , 201 in outwardly facing surfaces 190, 200. The push-fitting distorts the shape of the head portion, allowing it to enter into and be retained in (i.e. engage) the recess. The head portion can be removed by pulling it out, but significant resistance is encountered when doing this. Protrusions 220 extend along the length of first seal 25 perpendicular to the plane of Figure 9. These engaged members (protrusions 220 and recesses 191 , 201 ) help retain first seal 25 in the correct position.
First pane of glass 34 is 12.8mm St Gobain Stadip Silent laminated glass (Vetrotech Saint-Gobain UK Ltd, Bradford, UK). Second pane of glass 35 is 8.8mm St Gobain Stadip Silent laminated glass (Vetrotech Saint-Gobain UK Ltd, Bradford, UK). An additional "cushioning" 2mm deep Shore 35 silicone tape seal is applied to the bottom load (weight) bearing surface of frame F and which surface extends between frame F first and second outwardly facing surfaces 250, 251 and spacer bar 180 first and second outwardly facing surfaces 190, 200 respectively and is generally perpendicular to spacer bar first and second outwardly facing surfaces 190, 200 respectively.
The first and second panes of glazing material 34, 35 are then put in position in the frame, with remotely operable blind 1 12 positioned between them. Thus, glazing unit volume 11 1 is defined between first and second panes of glass 34, 35, frame F, and first seals 25.
Thus, first seals 25 abut outwardly facing surfaces 190, 200 of spacer bar 180 and first major surface S2, S3 of first and second panes of glass 34, 35 respectively. An air gap 25A is left between frame F and the minor surfaces of the panes of glass 34, 35 (except for the bottom minor surface which contacts the cushioning silicone tape seal. Air gap 25A provides the required engineering tolerances for the size of the panes of glass 34, 35 such that they can be slightly under- or over-sized without affecting the effectiveness of the glazing unit 100, i.e. glazing unit 100 is tolerant to minor variations in panes of glass 34 from an ideal size. Indeed, the provision of air gaps 25A allows for differential thermal expansion coefficients of the panes of glass 34, 35 and the frame F. Once compressive force is exerted upon it, the correct positioning of first seal 25 is further assisted by teeth 230 on outwardly facing surfaces 190, 200 of spacer bar 180 which bite into it and retain it in position, and which further assist in effecting a gas seal. Second seals 26 are then applied to the second major surface S1 , S4 of first and second panes of glass 34, 35 respectively.
First and second panes of glass 34, 35 are held in place by compression caps comprising powder coated aluminium compression cap bodies 8, 9, 10, 1 1 and compression means in the form of self-tapping screws 22.
General positioning of compression cap bodies 8, 9, 10, 1 1 is effected by a shoulder portion 280 of compression cap bodies 8, 9, 10, 1 1 abutting complementary shoulder portions 290 of corner post 1 , T-post 2, floor channel 3, door post 4, mullion 5, ceiling channel 6 and transom 7 generally perpendicular to outwardly facing surfaces 250, 251 .
The gas seal achieved by compression cap bodies 8, 9, 10, 1 1 is further enhanced by elongate Shore 35 silicone pressure seal strip 27 which is positioned in and protrudes from recess 27A. As screw 22 is tightened, it causes compression cap body 8, 9, 10, 1 1 to contact and compress the protruding portion of pressure seal strip 27, enhancing the gas seal. The gas seal achieved by compression cap body 9 is further enhanced by pressure seal strip 30A which is contained in and protrudes from recess 30 in compression cap body 9. As screw 22 is tightened, it causes frame F contact and compress the protruding portion of pressure seal strip 30A, enhancing the gas seal.
Compression cap bodies 8, 9, 10, 1 1 are provided with a threaded recess 240 but do not have an orifice defined in them allowing passage of self-tapping screw 22 through them. Rather, they are indented at a position through which self-tapping screw 22 is to pass, and clockwise rotation of self-tapping screws 22 causes them to tap into compression cap bodies 8, 9, 10, 11 and to eventually pass through and bite into and self tap into opposed first and second outwardly facing surfaces 250, 251 of corner post 1 upon which they are thus mounted.
A portion of compression cap bodies 8, 9, 10, 1 1 overlaps second major surfaces S1 , S4 of glass panes 34, 35 and second seal 26. The underside (inwardly facing side) of that overlapping portion of compression cap bodies 8, 9, 10, 1 1 is provided with a plurality of teeth 260 which bite into and retain in position seal 26.
Hermetic washer seal 32 is positioned between self-tapping screw 22 and compression cap bodies 8, 9, 10, 11 so that when self -tapping screw 22 is sufficiently tightened, compressive pressure will be exerted through it upon compression cap bodies 8, 9, 10, 1 1 , further enhancing the seal achieved.
When tightening of self-tapping screw 22 has been completed, threaded powder coated aluminium cover means 28 is screwed into threaded recess 240 to provide a generally smooth surface to compression cap bodies 8, 9, 10, 1 1 and thus enable convenient cleaning and reduce the opportunity for dirt or microbes to be retained by the compression caps. The above description of corner post 1 and associated components applies mutatis mutandis to the additional frame sections, namely T-post 2, floor channel 3, door post 4, mullion 5, ceiling channel 6 and transom 7.
As shown in Figure 15, ceiling channel 6 is secured in ceiling 130 by long screw 23. As shown in Figure 13, at floor height floor channel 3 sits on floor 120 on top of which is provided generally gas impermeable vinyl floor covering 300 which curves upwards as it reaches floor channel 3 and is engaged with and retained between compression cap body 8 and floor channel 3, Teeth 241 of compression cap body 8 ensure that it is engaged with vinyl floor covering 300. Thus, a complete pressure sealed room is provided which is simple and easy to clean to a high level.
Pressure leakage tests
With a pressure sealed room 310 fabricated as shown in Figure 18, the following air leakage tests were performed by Stroma Technology (Castleford, UK; www.stroma.com) on 17 August 2009.
The room was fabricated as shown in Figure 18, giving:
Envelope Area: 105.8 m 2
Exposed Envelope Area: 82.3 m 2
Volume: 70.6 m 3
Equipment Used
Table 1
Airflow Developments - AIRFLOW Developments Ltd, High Wycombe, UK; www.airflow.co.uk.
Table 2 - Temporary Sealing within Test Zone
I I Response Temporary seals on door and threshold? No
Additional assistance keep the Patient Room / Airlock Lobby door closed Yes on the gaskets?
Lights temporarily sealed? No
1 No. smoke detector sealed with visqueen and tape Yes
Extracts grilles temporarily sealed? N/A
Electrical socket 290 temporarily sealed? Yes
1 No DF panel fitted and for the HVLT, and sealed? Yes
Description of Test Procedure:
A temporary panel was created using MDF, with an opening (mounting plate 380) made for the HVLT to connect to, and fitted to the timber stud dry-lined wall 370 within the inner region (patient room) 320. All joints were taped to prevent air egress through the hoarding. Hermetically sealing sliding door 340 between the inner region 320 and outer region (airlock lobby) 330 was closed and disabled, with external pressure applied to ensure the door gaskets were fully utilised.
Hermetically sealing sliding door 350 between the outer region 330 and the exterior of room 310 was opened and disabled to give an unrestricted free-air supply to internal wall 323 comprising glazing units and frame 360 and door 340 between the outer region 300 and inner region 320, as well as to the three external walls 321 , 322, 370 of the inner region (patient room) 320.
Inner region (patient room) 320 was tested with the aforementioned temporary seals in place. In order to depressurise the inner region (patient room) 320, the HVLT was set-up within it the with the supplied type "H" nozzle (56mm internal diameter), or the supplied type "G" nozzle (28.5mm internal diameter), which was fitted into an MDF profile located on the wall 370 of the inner region 320. The Airflow Developments Manometer LM1 was connected to the HVLT, and set-up to produce results for the HVLT utilising the H/G nozzle. The air leakage characteristics of the structure were determined by collecting pairs of data from LM1 , which cross references the room differential pressure, and volumetric flow rate (through the HVLT). The room pressure was adjusted by altering the corresponding HVLT flow rate. Air was extracted from the room at a variety of flow rates to create subsequent pressure differentials (ranging from -101 Pa down to -39 Pa) between the internal and external environment of the structure. The process was repeated with the HVLT (mounted with H, and G nozzles respectively) external to the enclosure (to pressurise the enclosure) utilising the same mounting plate fixed to the timber studwork wall. Pairs of figures were recorded within the room pressure range of 97 Pa to 37 Pa. The results given are based upon air flows at a standard air density (i.e. 1.2 kg/m 3 ).
Results:
Table 3 - Pressurisation data
Table 4 - Pressurisation equations
Table 5 - Depressurisation data
Negative Standard In (Room In (Flow Log Error Nozzle Flow Room Flow Rate Pressure) Rate) (m 3 /hr) Pressure (Pa) (l/s)
101 20.05 4.62 3.00 -0.7% H 72.180
89 18.60 4.49 2.92 -3.5% H 66.960
80 17.16 4.38 2.84 -4.2% H 61.776
67 15.72 4.20 2.75 -9.7% H 56.592
76 17.01 4.33 2.83 -7.4% H 61.236
70 15.39 4.25 2.73 -4.3% G 55.404
63 14.30 4.14 2.66 -5.6% G 51.480
56 13.29 4.03 2.59 -7.8% G 47.844
51 12.61 3.93 2.53 -10.0% G 45.396
45 1 1.78 3.81 2.47 -13.1 % G 42.408
39 10.71 3.66 2.37 -15.1 % G 38.556
Table 6 - Depressurisation equations The pressurisation and depressurisation results were plotted (not shown), and respective lines of best fit applied, which both demonstrated a very good correlation (where 1 is a perfect fit) i.e. the r 2 value for pressurisation is 0.9912, and the r 2 for depressurisation is 0.9892. From the two lines of best fit for pressurisation and depressurisation an average line of best fit was calculated. This gave a slope (n) of 0.7530, and a coefficient (C) if 0.6206 l/s.
Thus, the equation of the exponential average line of best fit is:
Flow (l/s) = 0.6206 χ [Room Pressure (Pa)] A 0.7530
This can be expressed as:
G = Standard Volumetric Flow (l/s), at room pressure ΔΡ (Pa)
From this relationship it can be determined the total Patient Room Flow Rate at a room pressure (i.e. pressure bias) of 55 Pa is:
Flow @ 55 Pa = 0.6206 χ 55 07530
Flow @ 55 Pa = 12.69 l/s, which is equal to 45.68 m 3 /hr
Based upon an exposed surface area the following properties of the enclosures can be determined:
Air Leakage Index @ 55 Pa = 0.55 n Vhr.m 2
The leakage calculated through every square metre of the wall area (inc. sliding door), and the roof area alone, every hour. Air Permeability @ 55 Pa = 0.43 rrvVhr.m 2
The leakage calculated through every square metre of the wall area (inc. sliding door), and the roof area alone, and floor area, every hour.
Air Change Rate @ 55 Pa = 0.65 hr "1
This is the time required for a complete volume change of air within the enclosure.
Sound insulation tests
With a pressure sealed room 310 fabricated as shown in Figure 18, the following sound insulation tests were performed by Stroma Technology (Castleford, UK; www.stroma.com) on 20 August 2009. Room 310 was constructed within a large metal working warehouse upon a concrete floor. Due to the conditions of the testing, the results below can only be used as an indication of the sound insulation values that would be achieved under test when in situ in its intended location. Airborne tests were performed based on BS EN ISO 140-4:1998 "Field measurements of airborne sound insulation between rooms".
Table 7 - sound insulation tests performed
Description Source Room Receiver Room Measured Measured Partition D nT ,w (dB) R'w (dB)
Volume Volume
Description Area
(m 3 ) (m 3 )
(m 2 )
Test 1 (Large Warehous
71 .0 >200 16.4 46 46 Room) e
Test 2 (Large Small
71 .0 53.0 16.4 33 33 Room) Room
Test 3 Large
>200 71 .0 16.4 37 42 (Warehouse) Room
Test 1 :
Area S of separating element: 16.40 m 2
Source room volume: 71 .00 m 3
Receiving room volume V: 200.00 m 3
Results:
Table 8
Frequency R'
F 1/3 Octave
Hz dB
50
63
80
100 22.8
125 20.9
160 26.2
200 30.9
250 32.5
315 36.4
400 37.4
500 39.2
630 42.0
800 41 .8 1000 38.6
1250 36.6
1600 39.7
2000 43.6 B
2500 45.3 B
3150 44.7
4000
5000
B: R' >= value shown
Rating according to ISO 717-1
fl' w (C;C tr ) = 40 (-2; -5) dB
Evaluation based on field measurement results obtained in one-third-octave bands by an engineering method. Cso-3150 = N/A dB; C 50 -5ooo = N/A dB; C100-5000 = N/A dB;
C t r,so-3i 5o = N/A dB; C tr ,5o.5ooo = N/A dB; C, r , 10 o.5ooo = N/A dB;
Test 2:
Area S of separating element: 16.40 m 2
Source room volume: 71 .00 m 3
Receiving room volume V: 53.00 im 3
Results: Table 9
Frequency R'
F 1/3 Octave
Hz dB
50
63
80 100 21 .0
125 23.6
160 28.2
200 29.4
250 31.9
315 31 .9
400 31 .8
500 32.3
630 34.2
800 33.9
1000 32.4
1250 31 .7
1600 32.4
2000 34.2
2500 32.3
3150 31 .4
4000
5000
Rating according to ISO 717-1
(C;C tr ) = 33 (-1 ; -1) dB Evaluation based on field measurement results obtained in one-third-octave bands by an engineering method.
Cso-3150 = N/A dB; C50.5000 = N/A dB; C100-5000 = N/A dB;
C tr ,5o-3i so = N/A dB; 0, Γ , 50 -5οοο = N/A d B ; C„,i 00-5000 = N/A d B ;
Test 3:
Area S of separating element: 16.40 m 2
Source room volume: 200.00 m 3
Receiving room volume V: 71 .00 m 3
Results: Table 9
Rating according to ISO 717-1
R' w (C;C tr ) = 38 (-2; -6) dB
Evaluation based on field measurement results obtained in one-third-octave bands by an engineering method. Cso-3150 = N/A dB; Ο 50 . 5 οοο = N/A dB; C100-5000 = N/A dB; C, r ,5o-3i5o = N/A dB; C tr , 5 o-5ooo = N/A dB; C„, 10 o-5ooo = N/A dB; Maximum/minimum pressure testing
The room used in the above "Pressure leakage tests" was used to determine the maximum pressure which it was capable of withstanding. The above apparatus was used and pressure increased until the pressure sealed room failed. Results show that the glazing units used are capable of standing a pressure of ±1 15Pa.
Time to pressure
Results of experiments performed using the equipment used for the "Pressure leakage tests" were that the pressure sealed room of the present invention could be rapidly pressurised, with a pressure of 55 Pa being reached in about 90 seconds, and a pressure of 1 15 Pa in about 180 seconds. It will be appreciated that it is not intended to limit the present invention to the above embodiments only, other variations and modifications being readily apparent to one of ordinary skill in the art.
Reference signs:
1 - corner post
2 - T-post
3 - floor channel
4 - door post
5 - mullion
6 - ceiling channel
7 - transom
8 - compression cap body
9 - compression cap body
10 - compression cap body
11 - compression cap body
22 - self-tapping screw
23 - long screw
25 - first seal
25A - air gap
26 - second seal
27 - pressure seal strip
27A - recess
28 - cover means
30 - pressure seal strip
30A - recess
32 - hermetic washer seal
34 - first pane of glass
35 - second pane of glass
100 - pressure sealed room
110 - glazing unit
11 1 - glazing unit volume
112 - blind
115 - hermetically sealing automatically sliding door 120 - floor
130 - ceiling
140 - glazing unit
150 - hermetically sealing automatically sliding door 160 - outer region (of room 100)
170 - inner region (of room 100)
180 - spacer bar
190 - first outwardly facing surface
191 - recess
200 - second outwardly facing surface
201 - recess
210 - peripheral surfaces (of first and second panes of glass 34, 35) 220 - protrusion
230 - teeth
240 - threaded recess
241 - teeth
250 - outwardly facing surface
251 - outwardly facing surface
260 - teeth
270 - surface (of corner post 1 )
280 - shoulder portion (of compression ca bodies 8, 9, 10, 1 1 ) 290 - shoulder portion (of corner post 1 )
300 - vinyl floor covering
310 - pressure sealed room
320 - inner region (patient room)
321 - external wall
322 - external wall
323 - internal wall
330 - outer region (airlock lobby)
340 - hermetically sealing automatically sliding door
350 - hermetically sealing automatically sliding door
360 - glazing unit/frame arrangements
370 - wall
380 - mounting plate
390 - 230V twin socket
F - frame
51 - second major surface (of first pane of glass 34)
52 - first major surface (of first pane of glass 34) - first major surface (of second pane of glass 35) - second major surface (of second pane of glass 35)
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