■ Heating
Choosing the right insulation Continued from page 31 First and foremost is to choose an insulation material that will last and not deteriorate over time. What environmental conditions will affect it? The material has to stand up to the temperature required of it – both on the inside and on the outside. The material may also have to be impervious to chemicals, ultraviolet light, vermin and varmint attack, and of course water. If exposed to water, it must maintain its insulating qualities when wet and if it is subject to mechanical stress, it has to be strong enough to maintain its own integrity and that of the tubing it contains.
with quite high water temperatures, thermal and mechanical stress and chemical attack. But I’ve been looking for something readily available at a more modest price point – insulation that can be buried in concrete and can deal with fluid temperatures and ambient temperatures no more than 180°F, and ambient temperatures (outside the insulation) of no less than 32°F. The normal maximum temperature difference between fluid temperature and ambient will likely never be more than 50°F, so it doesn’t have to have heavy duty R-value. That is where I have been having a bit of a problem trying to source an equivalent to the grey stuff I saw in
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Roy Collver is an author and consultant on hydronic heating based in Peachland, B.C. He can be reached at hoth2o@shaw.ca
Introducing the Vitocrossal 200, CM2: a brand new face with familiar features
There were unique insulation materials for various applications – one size/type does not fit all.
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You can see what I mean about these products being highly engineered. Buying the cheap split-foam pipe insulation may be appealing – but will it last, and will it do the job you need it to do? Every insulating material should have a documented thermal resistance value (R-value) and calculations have to be made based on: how hot the pipe is inside the insulation versus how cold the temperature will be outside the insulation and how long the pipe is versus the flow rate of fluid through the pipe. With this information, calculations can be made as to out how thick the insulation should be given a specific product’s R-value. You have to calculate how much heat will be lost on the journey from your heat source to where you need to use the heat and then come up with a cost-effective solution. Got a headache yet? When you start to look at insulation selection closely, you can see why I make the point that you should find a supplier who is: local (or at least on this side of the 49th parallel), has the documentation needed to prove that the material can stand up to its intended use and has the engineering expertise to assist you in the design process. High density, high temperature, elastomeric pipe insulation such as the aforementioned “Armaflex” or “KFlex” are fabulous products and, although they will do an excellent job, they were originally designed for more severe service conditions – higher temperatures, UV resistance, water and chemical resistance, etc. For radiant applications, the 3/8” wall thickness is just fine. The companies listed above, supply some pretty amazing pre-insulated products capable of being directly buried in the ground or slab and able to deal
Europe. Nobody I have talked to about this can point me in the right direction – although as soon as this is in print, I’m sure all kinds of suppliers will speak up. In the meantime, I will keep looking. ✚
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July/August 2013 – Plumbing & HVAC
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