NARM

Establishing the optimum rooflight area with NARM

  • 31 Jan 2018

NARM, The National Association of Rooflight Manufacturers, have been explaining how minor differences in rooflight area can make a substantial impact on light levels and energy usage, courtesy of its Technical Committee.

With it being common knowledge that specified rooflights save energy and lower CO2 emissions, this also makes them a vital component to meeting Part L of The Building Regulations covering the Conservation of Fuel & Power and the equivalent regional regulations.

Research has shown minimal losses in thermal insulation are massively offset by energy savings, leading to a lessened demand for electric lighting and, generally speaking, the larger the rooflight area, the more savings could be potentially made. There is, however, a limit before overheating could manifest as an issue, so an optimum area has to be identified.

A specific solution never exists in terms of rooflight area, with judgement essential based on whatever the project may be. However, the example (click here to see) shows how data gathered can be used to inform a decision. NARM can provide data for varying building locations, for rooflights with varying degrees of light transmission and for different daily time windows.

The first consideration in establishing rooflight area is the use of the building; for example, in retail and manufacturing areas, the recommended light level* is 500 Lux.

Establishing the appropriate rooflight area to achieve the desired light level is next; the larger the rooflight area, the increased amount of hours every year the necessary light level will be natural light. This is a vital factor affecting energy and emissions reductions, as there is no need for electric lighting during these hours.

The graph in the link shows a single storey building in London, between 6am and 6pm daily, with rooflights providing 50% light transmission. It shows, as the rooflight area across the bottom of the graph increases, the length of time a given illumination level is achieved, is extended.

So a building which requires 500 Lux, the yellow line shows with 10% rooflights, 500 lux would be achieved for approximately 2000 hours (46% of the working year).

 

For further information, please contact NARM using the contact details on our website, where you will be directed to the appropriate person.

Visit NARM's website

Leave a Reply

Latest news

MRA

MRA shortlisted for 15 Construction Marketing Awards

Full-service agency MRA Marketing has been shortlisted for 15 awards across 10 categories in this year’s prestigious Construction Marketing Awards (CMAs).

Posted in Articles, Awards, Building Associations & Institutes, Building Industry Events, Building Industry News, news

ASSA ABLOY

ASSA ABLOY hands-free solutions to help limit the spread of COVID-19

There are a range of hands-free door opening solutions – available to suit all budgets and needs – that can help minimise the spread of infection, says the ASSA ABLOY Door Hardware Group.

Posted in Access Control & Door Entry Systems, Architectural Ironmongery, Articles, Building Industry News, Building Products & Structures, Doors, Health & Safety, news, Security and Fire Protection

C-TEC

C-TEC creates new evacuation alert video

Leading life-safety systems manufacturer, C-TEC, has created a new Evacuation Alert Systems video.

Posted in Articles, Building Industry News, Building Services, Facility Management & Building Services, Health & Safety, Security and Fire Protection, Video of the Week

Baxi

Launch of Baxi Assure offers the complete home service for contractors

As the UK moves towards net-zero carbon emissions by 2050 and an ever-growing demand for housing, Baxi has launched a suite of products and services for heating and hot water systems – Baxi Assure.

Posted in Articles, Building Industry News, Building Services, Heating Systems, Controls and Management, Heating, Ventilation and Air Conditioning - HVAC, Innovations & New Products, Posts, Sustainability & Energy Efficiency