[Bldg-sim] comparing insulated core masonry block with stick built

[Karen Walkerman]

REMRate merely takes the UA of the whole house and calculates energy use
based on heating degree and cooling degree days.  It also takes into account
thermal gain from windows, infiltration and calculates internal energy use
(lights, appliances, etc), but does not do a full 24-hr 365 day simulation.

For frame walls with batt insulation, both REMRate and the eQuest Wizard
will calculate the overall wall U-value based on their estimate of the ratio
of framing material to insulation.  For advanced construction techniques, I
usually calculate average U-value the parallel path method.  I then enter
this as "continuous" insulation in either REMRate or eQuest, and then other
relevant information, such as thermal mass.  eQuest will take into account
thermal mass, whereas I don't believe REMRate does.  Sometimes masonry wall
manufacturers will claim a higher than actual R-value due to the thermal
mass properties of the wall.  This is one case where eQuest will do a better
job--, if entered properly.  I don't believe REMRate takes thermal mass into
account.

Unfortunately though, eQuest can't be used for HERS ratings, so if that is
your final goal, you're stuck with what you have.

Hope this helps,

~Karen~

On Jan 17, 2008 2:57 PM, Christian Stalberg <cstalberg at southern-energy.com>
wrote:

>   I'm doing a modeling comparison in REM/Rate of two identical houses
> except one has 8" insulated core masonry block walls whereas the second has
> 4" wood stud insulated walls. Both walls end up having comparable U values.
> REM/Rate shows negligible difference in energy usage. I am suspicious that
> REM/Rate does not model the thermal bridging and mass features very well.
> Would I be better served performing this comparison in DOE-2 or would the
> results not be that much different?
>
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