I have heard of software or online calculators that can calculate the location of the dew point in a wall assembly but have not had much luck finding them. Can anyone point me in the right direction?
hmm...i'm not necessarily sure if there is anything online but i vaguely remember seeing something like that during a lunch-n-learn years ago. it was probably an insulation manufacturer so maybe it would be worth poking around one of their websites...maybe dow, johns manville, etc.
Pretty sure that's the Dow people...maybe Owens Corning. Someone who manufacturers extruded insulation.
Send them an Autocad wall section and they'll calculate where the dewpoint is and tell you how to make it better - or to save you the time, just take the batt insulation out of the cavity and put the foam on the outside face of the studs. That was the whole point of the lunch-n-learn I saw.
This one of the things which I don't fully understand. Why the Hell it can be so fricking difficult to get a reading on something like a dew point. There was a significant study done at oakridge testing labs a few years ago which delt with heat loss and metal stud walls. Thing is since there there have been a number of different modifications to the studwalls to reduce the actual contact of the stud to the exterior
fascia material, inorder to reduce heat tranfer. However never have been able to come up with anything more current. If your placing insulation on the exterior face of the wall sheathing then in my opinion your creating a heck of alot of head aches for the builder and for yourself. Detailing can be a nightmare. I sure wish the energy guys would talk with the structural guys on this one and come up with some workable solutions.
It was great in the European context because they get data from product manufacturers so you can drop in actual products rather than trying to chase U/R values and fudging generic properties. Gives you dew point and heat loss for every month based on your location and spits out a neat little U-Value report.
Not sure how it works in the US setting since the products are probably different. It's use is limited here in the UK now as most buildings are now rated using very complicated SAP calcs which give more flexibility in design but mean you usually need a specialist to do the report. I've seen spreadsheets used to do simple SAP calcs and it'd give you a breakdown just trying to find the information it demands.
Sadly we're now more reliant on slacker mech engineers now...*sigh*
May 1, 08 7:41 am ·
·
Block this user
Are you sure you want to block this user and hide all related comments throughout the site?
Archinect
This is your first comment on Archinect. Your comment will be visible once approved.
Dew point in wall
I have heard of software or online calculators that can calculate the location of the dew point in a wall assembly but have not had much luck finding them. Can anyone point me in the right direction?
hmm...i'm not necessarily sure if there is anything online but i vaguely remember seeing something like that during a lunch-n-learn years ago. it was probably an insulation manufacturer so maybe it would be worth poking around one of their websites...maybe dow, johns manville, etc.
Pretty sure that's the Dow people...maybe Owens Corning. Someone who manufacturers extruded insulation.
Send them an Autocad wall section and they'll calculate where the dewpoint is and tell you how to make it better - or to save you the time, just take the batt insulation out of the cavity and put the foam on the outside face of the studs. That was the whole point of the lunch-n-learn I saw.
This one of the things which I don't fully understand. Why the Hell it can be so fricking difficult to get a reading on something like a dew point. There was a significant study done at oakridge testing labs a few years ago which delt with heat loss and metal stud walls. Thing is since there there have been a number of different modifications to the studwalls to reduce the actual contact of the stud to the exterior
fascia material, inorder to reduce heat tranfer. However never have been able to come up with anything more current. If your placing insulation on the exterior face of the wall sheathing then in my opinion your creating a heck of alot of head aches for the builder and for yourself. Detailing can be a nightmare. I sure wish the energy guys would talk with the structural guys on this one and come up with some workable solutions.
I got a trial version of this a while back...
http://www.builddesk.com/sw14855.asp
It was great in the European context because they get data from product manufacturers so you can drop in actual products rather than trying to chase U/R values and fudging generic properties. Gives you dew point and heat loss for every month based on your location and spits out a neat little U-Value report.
Not sure how it works in the US setting since the products are probably different. It's use is limited here in the UK now as most buildings are now rated using very complicated SAP calcs which give more flexibility in design but mean you usually need a specialist to do the report. I've seen spreadsheets used to do simple SAP calcs and it'd give you a breakdown just trying to find the information it demands.
Sadly we're now more reliant on slacker mech engineers now...*sigh*
Block this user
Are you sure you want to block this user and hide all related comments throughout the site?
Archinect
This is your first comment on Archinect. Your comment will be visible once approved.