Demand Controlled Ventilation
Air to Water Heating
Century Homes Timber Frame
Thermal bridging typically occurs at the junctions between plane building elements, e.g. at wall/roof and wall/floor junctions, and around openings, e.g. at window jambs, where the continuity of the insulation is interrupted.
Thermal bridging increases the heat loss and also the risk of condensation due to the lower localised internal surface temperatures.
The extra heat loss at a thermal bridging is measured by way of its linear thermal transmittance or Psi (Ψ) value in units of (W/mK).
Building Regulations require that heat loss calculations should include the effects of thermal bridges when calculating the Energy Performance Coefficient (EPC) and Maximum Permitted Energy Performance Coefficient (MPEPC) using DEAP.
Warm air can store much more moisture than cold air. When warm and moist air makes contact with a cold surface the moisture condensates which in a building can lead to mould and therefore a deterioration of the building fabric. With the use of Kingspan Century Building Systems and their intelligent detailing, thermal bridging is all but eradicated – avoiding condensation and thus preventing any potential for moisture to build up within the building envelope, preserving its integrity and extending its life span.
All Kingspan Century systems have had extensive Thermal Modelling of critical junctions to ensure that Cold Bridging has been eliminated by design.
All thermal insulation materials work on a single basic principle: heat moves from warmer to colder areas. Therefore, on cold days, heat from inside a building seeks to get outside and on warmer days, the heat from outside the building seeks to get inside.
Insulation is the material which slows this process. Rigid phenolic and urethane insulation materials have tiny pockets of trapped gas, these pockets resist the transfer of heat.
Heat transfer occurs when a hot surface is surrounded by an area that is colder, heat will be transferred and the process will continue until both are at the same temperature. Heat transfer takes place by one or more of three methods; conduction, convection and radiation.
In order to perform effectively as an insulant a material must restrict heat flow by any, and preferably, all three methods of heat transfer. Most insulants adequately reduce conduction and convection elements by the cellular structure of the material. The radiation component is reduced by absorption into the body of the insulant and is further reduced by the application of a bright foil outer facing to the product.
Air leakage is defined as the flow of air through gaps and cracks in the building fabric. Uncontrolled air leakage increases the amount of heat loss as warm air is displaced through the envelope by colder air from outside. Air leakage of warm damp air through the building structure can also lead to condensation within the fabric (interstitial condensation), which reduces insulation performance and causes fabric deterioration.
Air leakage is a ‘double whammy’ in energy efficiency terms, because warmed air leaks out and cold air leaking in then needs to be heated.
The airtightness of a dwelling, or its air permeability, is expressed in terms of air leakage in cubic metres per hour per square metre of the dwelling envelope area when the building is subjected to a differential pressure of 50 Pascals (m3/(h.m2)@50Pa).
The dwelling envelope area is defined in this context as the total area of all floors, walls and ceilings bordering the dwelling, including elements adjoining other heated or unheated spaces.
Air permeability figure are used in DEAP calculations and poor airtightness can significantly affect the calculated thermal performance of a building.
A reduction in air permeability (@ 50Pa) from 15 (m3/(h.m2 ) to 5 (m3/(h.m2)
= Energy savings of approximately 25%
The air permeability of a building can be determined by means of a pressure test conducted using a device referred to as a Blower door Building Regulations 2011 TGD-L (Dwellings) indicates that reasonable provision for airtightness is to achieve a pressure test result of no worse than 7m3/(h.m2)@50Pa., however best practice is regarded as less than 3m3/(h.m2)@50Pa, with Passive House requirements being less than 1m3/(h.m2)@50Pa.
All Kingspan Century systems, with their factory manufactured applied airleakage measures offer the highest levels of airtightness, typically achieving less than 2m3/(h.m2)@50Pa and can be designed to achieve less than 1m3/(h.m2)@50Pa.
However in traditional construction it is necessary to understand that air leakage routes are complex, and subsequent works such as service penetrations can affect airtightness.
Developed to deliver superior thermal performance, Kingspan Century’s ULTIMA Wall System not only meets the current building regulations, but exceeds them.
ULTIMA represents the next level in timber frame technology, delivering exceptionally high levels of thermal performance and airtightness and eliminating Cold Bridging due to its continuous high performance Kooltherm insulation lining.
Factory manufactured under strict quality control, the ULTIMA Wall System is quick and easy to install – reducing labour costs and build times.
Kingspan Century offer prefabricated floor panels constructed from lightweight yet strong open web joists.
Open web joists are the next generation of high performance engineered timber achieving greater clear spans than solid or I-Joists, reducing the need for internal load-bearing walls and giving you greater flexibility.
The innovative use of high strength steel webs and lightweight timber flanges combine to make a structural beam that is capable of increased spans than would be possible with a beam made of timber alone.
Open web joists also facilitate simple integration of services such as ducting for heat recovery ventilation units, plumbing pipework and electrical cabelling.
Benefits offered by open web joists:
Our Open Web Joists in prefabricated panels are available in a range of joist depth from 202 – 421mm