Designing Buildings - User contributions [en]

User:JenAct Ltd

2020-09-18T12:28:43Z

Stephen Hawes:

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:58:22Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses from buildings.

=== Introduction. ===

Since the emergence of the Covid-19 pandemic there has been a huge increase of interest in UV disinfection for both surfaces and air. Also a similar surge in questions and enquiries from Architects, Building / Facility Mangers, HVAC experts and building owners.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

=== How does it remove microorganisms and viruses? ===

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

=== How can UVC be applied to 'disinfect' air in buildings? ===

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three primary options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V_-_iso_no_label.jpg|link=File:GRU-V_-_iso_no_label.jpg]]

GRU-V wall mounted air purifier from JenAct - [https://www.jenact.co.uk/uv-air-disinfection-medical https://www.jenact.co.uk/uv-air-disinfection-medical]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

[[File:Ceiling.png|link=File:Ceiling.png]]

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[File:Torpedo.jpg|link=File:Torpedo.jpg]]

In duct mounted Torpedo device from JenAct - [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection]

=== ===

=== Conclusion. ===

The key to an efficient but effective system is frequently software modelling of the intended ventilation system and UV components. This ensures correct 'dosage'. Companies such as JenAct provide suitable in-house modelling services to achieve this. [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection].

Of course steps must also be taken to ensure people are not directly exposed to UV light. The installation is either self contained or installed with safety interlocks to remove power from the UV tubes when maintenance access is required. For example to replace the tubes after 8,000 hours of use.

A suitably designed and installed system can provide effective removal of airborne bacteria and viruses with very little ongoing maintenance or spare part costs.

Given the global upheaval cause by the Covid-19 pandemic and the increasing and ongoing demands to make using buildings safer it seems likely that the use of UV-C air disinfection will become common place.

[[Category:Articles_needing_more_work]] [[Category:Construction_techniques]] [[Category:Cost_/_business_planning]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]]

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:57:00Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses from buildings.

=== Introduction. ===

Since the Coivid-19 pandemic there has been a huge increase of interest in UV disinfection for both surfaces and air. Also a similar surge in questions and enquiries from Architects, Building / Facility Mangers, HVAC experts and building owners.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

=== How does it remove microorganisms and viruses? ===

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

=== How can UVC be applied to 'disinfect' air in buildings? ===

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three primary options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V_-_iso_no_label.jpg|link=File:GRU-V_-_iso_no_label.jpg]]

GRU-V wall mounted air purifier from JenAct - [https://www.jenact.co.uk/uv-air-disinfection-medical https://www.jenact.co.uk/uv-air-disinfection-medical]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

[[File:Ceiling.png|link=File:Ceiling.png]]

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[File:Torpedo.jpg|link=File:Torpedo.jpg]]

In duct mounted Torpedo device from JenAct - [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection]

=== ===

=== ===

=== Conclusion. ===

The key to an efficient but effective system is frequently software modelling of the intended ventilation system and UV components. This ensures correct 'dosage'. Companies such as JenAct provide suitable in-house modelling services to achieve this. [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection].

Of course steps must also be taken to ensure people are not directly exposed to UV light. The installation is either self contained or installed with safety interlocks to remove power from the UV tubes when maintenance access is required. For example to replace the tubes after 8,000 hours of use.

A suitably designed and installed system can provide effective removal of airborne bacteria and viruses with very little ongoing maintenance or spare part costs.

Given the global upheaval cause by the Covid-19 pandemic and the increasing and ongoing demands to make using buildings safer it seems likely that the use of UV-C air disinfection will become common place.

[[Category:Articles_needing_more_work]] [[Category:Construction_techniques]] [[Category:Cost_/_business_planning]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]]

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:54:57Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses from buildings.

=== Introduction. ===

Since the Coivid-19 pandemic there has been a huge increase of interest in UV disinfection for both surfaces and air. Also a similar surge in questions and enquiries from Architects, Building / Facility Mangers, HVAC experts and building owners.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

=== How does it remove microorganisms and viruses? ===

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

=== How can UVC be applied to 'disinfect' air in buildings? ===

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three primary options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V_-_iso_no_label.jpg|link=File:GRU-V_-_iso_no_label.jpg]]

GRU-V wall mounted air purifier from JenAct - [https://www.jenact.co.uk/uv-air-disinfection-medical https://www.jenact.co.uk/uv-air-disinfection-medical]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

[[File:Ceiling.png|link=File:Ceiling.png]]

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[File:Torpedo.jpg|link=File:Torpedo.jpg]]

In duct mounted Torpedo device from JenAct - [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection]

=== ===

=== ===

=== Conclusion. ===

The key to an efficient but effective system is frequently software modelling of the intended ventilation system and UV components. This ensures correct 'dosage'. Companies such as JenAct provide suitable in-house modelling services to achieve this. [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection].

Of course steps must also be taken to ensure an UV tube installation is either self contained or installed with safety interlocks to remove power from the UV tubes when maintenance access is required. For example to replace the tubes after 8,000 hours of use.

A suitably designed and installed system can provide effective removal of airborne bacteria and viruses with very little ongoing maintenance or spare part costs.

Given the global upheaval cause by the Covid-19 pandemic and the increasing and ongoing demands to make using buildings safer it seems likely that the use of UV-C air disinfection will become common place.

[[Category:Articles_needing_more_work]]

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:53:11Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses from buildings.

=== Introduction. ===

Since the Coivid-19 pandemic there has been a huge increase of interest in UV disinfection for both surfaces and air. Also a similar surge in questions and enquiries from Architects, Building / Facility Mangers, HVAC experts and building owners.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

=== How does it remove microorganisms and viruses? ===

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

=== How can UVC be applied to 'disinfect' air in buildings? ===

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three primary options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V_-_iso_no_label.jpg|link=File:GRU-V_-_iso_no_label.jpg]]

GRU-V wall mounted air purifier from JenAct - [https://www.jenact.co.uk/uv-air-disinfection-medical https://www.jenact.co.uk/uv-air-disinfection-medical]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

[[File:Ceiling.png|link=File:Ceiling.png]]

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[File:Torpedo.jpg|link=File:Torpedo.jpg]]

=== In duct mounted Torpedo device from JenAct - [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection] ===

=== ===

=== ===

=== Conclusion. ===

The key to an efficient but effective system is frequently software modelling of the intended ventilation system and UV components. This ensures correct 'dosage'. Companies such as JenAct provide suitable in-house modelling services to achieve this. [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection].

Of course steps must also be taken to ensure an UV tube installation is either self contained or installed with safety interlocks to remove power from the UV tubes when maintenance access is required. For example to replace the tubes after 8,000 hours of use.

A suitably designed and installed system can provide effective removal of airborne bacteria and viruses with very little ongoing maintenance or spare part costs.

Given the global upheaval cause by the Covid-19 pandemic and the increasing and ongoing demands to make using buildings safer it seems likely that the use of UV-C air disifncetion will become common place.

[[Category:Articles_needing_more_work]]

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:48:19Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses from buildings.

=== Introduction. ===

Since the Coivid-19 pandemic there has been a huge increase of interest in UV disinfection for both surfaces and air. Also a similar surge in questions and enquiries from Architects, Building / Facility Mangers, HVAC experts and building owners.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

=== How does it remove microorganisms and viruses? ===

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

=== How can UVC be applied to 'disinfect' air in buildings? ===

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three primary options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V_-_iso_no_label.jpg|link=File:GRU-V_-_iso_no_label.jpg]]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

[[File:Ceiling.png|link=File:Ceiling.png]]

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[File:Torpedo.jpg]]

=== Conclusion. ===

The key to an efficient but effective system is frequently software modelling of the intended ventilation system and UV components. This ensures correct 'dosage'. Companies such as JenAct provide suitable in-house modelling services to achieve this. [https://www.jenact.co.uk/uv-in-duct-disinfection https://www.jenact.co.uk/uv-in-duct-disinfection].

Of course steps must also be taken to ensure an UV tube installation is either self contained or installed with safety interlocks to remove power from the UV tubes when maintenance access is required. For example to replace the tubes after 8,000 hours of use.

A suitably designed and installed system can provide effective removal of airborne bacteria and viruses with very little ongoing maintenance or spare part costs.

Given the global upheaval cause by the Covid-19 pandemic and the increasing and ongoing demands to make using buildings safer it seems likely that the use of UV-C air disifncetion will become common place.

[[Category:Articles_needing_more_work]]

File:Torpedo.jpg

2020-09-18T11:27:13Z

Stephen Hawes: In duct Torpedo UV unit from JenAct

In duct Torpedo UV unit from JenAct

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:26:00Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses.

Introduction.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

How does it remove microorganisms and viruses?

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

How can UVC be applied to 'disinfect' air in buildings?

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V_-_iso_no_label.jpg|link=File:GRU-V_-_iso_no_label.jpg]]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

[[File:Ceiling.png]]

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[Category:Articles_needing_more_work]]

File:Ceiling.png

2020-09-18T11:25:21Z

Stephen Hawes: CEILING UV from JenAct

CEILING UV from JenAct

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:24:32Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses.

Introduction.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png|link=File:Spectrum.png]]

How does it remove microorganisms and viruses?

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

How can UVC be applied to 'disinfect' air in buildings?

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

[[File:GRU-V - iso no label.jpg]]

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[Category:Articles_needing_more_work]]

File:GRU-V - iso no label.jpg

2020-09-18T11:23:40Z

Stephen Hawes: GRU-V air purifier from JenAct

GRU-V air purifier from JenAct

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-18T11:22:13Z

Stephen Hawes:

A basic explanation of the science and application of using UV (Ultraviolet) light to remove airborne bacteria and viruses.

Introduction.

Various articles and reference papers are available providing facts, but also frequently opinions, about the use of UV light to 'disinfect' air and many other things. This is frequently complex and overly detailed for those interested in using UV to disinfect air in buildings. Also, much of the information online is rather dated. This brief article is intended to offer a basic factual primer to the subject based on current data, (September 2020).

What is UV light?

UV, (Ultraviolet), light is a range of wavelengths from 10nm to 400nm. This bandwidth has higher wavelengths than visible light but lower than X-rays and Gamma rays. UV is generated naturally by the sun. The UV bandwidth is divided in to three segments:

* UVA, or near UV (315–400 nm)
* UVB, or middle UV (280–315 nm)
* UVC, or far UV (180–280 nm)

To explain the characteristics of each of the above is beyond the scope of this article but is mentioned because UVC is particularly effective in disrupting bacteria and viruses. UV can be ‘good’ – e.g. UVB is responsible for formation of vitamin D. But also ‘bad’ – e.g. excessive exposure can cause sunburn and skin cancer.

All UV light is invisible. Ultra is Latin for “beyond” and Violet is the last colour of the rainbow.

[[File:Spectrum.png]]

How does it remove microorganisms and viruses?

UVC causes legions in the DNA and RNA. Sufficient exposure will cause enough damage to prevent replication so they cannot replicate, effectively killing the microorganism or virus.

Enough UVC exposure is the key to effective but energy optimised systems in buildings. Insufficient UVC = failure to destroy microorganisms and viruses. Excessive UVC generation = unnecessary initial cost and increased energy consumption costs.

How can UVC be applied to 'disinfect' air in buildings?

The core component of any building air UVC disinfection system is lighting tubes emitting the required wavelength and energy. Three options exist:

# Standalone or wall mounted devices.

Some type of cabinet or enclosure which uses fans to draw air across UVC emitting tubes. Efficacy is a product of air flow rate and tube output power.

Be wary of overly optimistic air flow rates. Devices incorporating other technologies should be critically assessed. HEPA filters clog and will need maintenance, Ozone emission is hazardous to humans, activated carbon becomes ineffectual over time.

# Upper air / room systems.

Upper air systems are ceiling mounted and deploy louvres to direct the UVC radiation at an angle to minimise exposure to people. Sufficient ceiling height is essential to avoid undesired exposure. Convection and additional mechanical air movement can be used to lift airborne contaminants upwards to the active area.

# In duct installations.

UVC can be used in ducted installations in one of two ways. Firstly, localised UVC can be applied to the system coils to maintain efficiency. But perhaps more importantly a properly modelled UVC Torpedo type installation will provide the correct balance of optimum germicidal effect combined with essential energy efficiency.

[[Category:Articles_needing_more_work]]

File:Spectrum.png

2020-09-18T11:20:53Z

Stephen Hawes: Spectrum of light

Spectrum of light

UV disinfection of building air to remove harmful bacteria and viruses

2020-09-17T14:22:51Z

Stephen Hawes: Created page with "= This article is a general and introductory explanation of the science and application of UV (Ultraviolet) light as a means to removing airborne bacteria and viruses. = [[Categ..."

= This article is a general and introductory explanation of the science and application of UV (Ultraviolet) light as a means to removing airborne bacteria and viruses. =

[[Category:Articles_needing_more_work]]