Masonite Beams Facilitate Whole House Mechanically Ventilated Heat Recovery Systems Installation
Clever preparation of engineered timber I-Joists is enabling Masonite Beams and Oregon Timber Frame to offer house builders an efficient solution for whole house Mechanically Ventilated Heat Recovery systems (MVHR) using pre-manufactured floor cassettes. The build method has already been used to achieve Code for Sustainable Homes Level 5.The solution is the result of a specific challenge presented recently by a housing site in Rotherham. In order to allow whole house MVHR without switching to metal web joists, Oregon Timber Frame needed to create 220mmx70mm holes in the web of 240mm I-Joists to accommodate the 210mmx 65mm rectangular ducting due to run within the floor void. However, holes of these dimensions in I-Joists of this depth are difficult to achieve due to engineering constraints.
To overcome this problem, the ducting was changed from a rectangular configuration to a 120mm round version. Oregon Timber Frame was able to drill 125mm holes in the I-Joists in its factory in order to supply all floors in pre-manufactured cassettes. On-site, the developer could then enjoy the benefits of floor cassette installation, including a speedy build process and improved health and safety, whilst the M&E contractor was able to install whole house MVHR through the floor void quickly and easily.
Commenting on the solution achieved for the Rotherham site by Oregon Timber Frame, Neil Lewis, Sales Director of Masonite Beams UK said:
“MVHR is likely to become standard in new houses. This particular combination of whole house MVHR ducting in pre-drilled floor cassettes offers several advantages, not just for developers but for the timber frame manufacturer too. For the latter, engineered timber I-Joists present a cheaper alternative to metal open web options with their ability to be manufactured quickly into floor cassettes that are light-weight, stiff, more dimensionally accurate, have less chance of installed shrinkage, and do not rely on a manufactured camber. For developers, here is a cost-effective answer to the challenge of using whole house MVHR in conjunction with tried and trusted engineered timber I-Joist floor cassettes. Of course, consideration needs to be given to the size and position of round holes through the joists, but this is easily accommodated so long as it is done at the initial design stage. ”
On behalf of Oregon Timber Frame, Richard Jarvis, the company's business development manager said:
“There are several advantages to installing round or oval duct, compared to rectangular duct. Round duct is the most efficient and economical means of conveying air. A round or oval shape results in lower pressure drops, thereby requiring less fan horsepower to move the air and, consequently, smaller equipment. The shape also has a comparatively lower surface area, and requires less insulation when externally wrapped. Spiral round and oval duct is available in longer lengths than rectangular duct, thereby eliminating costly field joints. The smaller surface areas of round and oval versions allow less heat loss or gain and are therefore more energy efficient.
“We have recently secured a new site of 106 units, of which six are to be built to Code for Sustainable Homes Level 5 incorporating whole house MVHR. We will be working closely with Masonite Beams to ensure the company's I-Joists help us to deliver on this order using the pre-drilled holes solution we have engineered.”
For further information on Masonite Beams UK Ltd visit www.masonitebeams.co.uk.
For further information on Oregon Timber Frame Ltd visit www.oregon.co.uk.