Re: [EnergyPlus_Support] Re: Increased insulation run

On Sun, Sep 9, 2012 at 10:02 AM, greenbuild15 <francois@xxxxxxxxxxxxxxx> wrote:

We often run into problems with over-insulation of buildings. In the warmer parts of the world, like South Africa where I live, the HVAC energy emphasis is on cooling. In building types with relatively high internal loads, we find that too much insulation increases the annual energy consumption. You lose less heat in colder months but end up having to use more HVAC cooling energy in hotter months to get rid of internal heat. You may also want to look at "The impact of increasing the building envelope insulation upon the risk of overheating in summer and increased energy consumption", Chvatal & Corvacho, 2009. - Francois Joubert.

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Niraj Poudel <nirajpdl@...> wrote:
>
> Try this paper.
>
> Kim, J.-J. and J. W. Moon (2009). Impact of insulation on building energy
> consumption. In Building Simulation - Eleventh International IBPSA
> Conference.
>
> Niraj
>
> On Sat, Sep 8, 2012 at 10:08 AM, Jim Dirkes <jim@...
> > wrote:
>
> > **

> >
> >
> > I agree with Vaibhav. Long ago, 25-30 years or so, I believe Larry
> > Spielvogel wrote an ASHRAE Journal article about this. The concept was
> > called "optimum U value" (or something similar).****

> >
> > The impact of using more or less insulation varies with climate and
> > internal loads, but it's somewhat counter-intuitive; more insulation is not
> > always better!****
> >
> > ** **
> >
> > *James V Dirkes II, PE, BEMP, LEED AP**
> > **www.buildingperformanceteam.com*<http://www.buildingperformanceteam.com/>
> > *
> > **Energy Analysis, Commissioning & Training Services**
> > *1631 Acacia Drive, Grand Rapids, MI 49504 USA
> > 616 450 8653****
> >
> > ** **
> >
> > *From:* EnergyPlus_Support@xxxxxxxxxxxxxxx [mailto:
> > EnergyPlus_Support@xxxxxxxxxxxxxxx] *On Behalf Of *Vaibhav Jain
> > *Sent:* Saturday, September 08, 2012 10:01 AM
> > *To:* EnergyPlus_Support@xxxxxxxxxxxxxxx
> > *Subject:* Re: [EnergyPlus_Support] Increased insulation run****
> >
> > ** **
> >
> > ****

> >
> > Hi,
> >
> > It might be because - when you have more insulation the heat from internal
> > gains is trapped inside (due to high insulation) even during night time
> > when outside is cooler. The opposite should be in case of low insulation.
> > Thats why high insulation is not always/everywhere good, it could bring
> > penalty too. ****
> >
> >
> > ****
> >
> > Vaibhav Jain****
> >
> > www.vaibhavjain.co****
> >
> > ** **
> >
> >
> >
> > ****
> >
> > On 7 September 2012 22:31, cmcdona037 <mcdonald.cliff@...> wrote:***
> > *
> >
> > ****

> >
> > Hello,
> >
> > I am doing a parametric run for a building with increased insulation. For
> > some reason, increasing the insulation results in a fairly significant
> > increase in building fan energy. However, when you look at the sizing, the
> > baseline case has slightly larger fans than the efficient case, as
> > expected. If you look at the occupant comfort report, most spaces are
> > slightly cooler in the summer and warmer in the winter in the efficient
> > case, so I guess this is the reason behind the higher energy use. But why
> > is this happening? Is there a setting I can use to get the same level of
> > heating/cooling in both cases?****
> >
> > ** **
> >
> > ****

> >
> >
> >
>
>
>
> --
> Niraj Poudel, Architectural Engineer.
> PhD student, PDBE Program.
> Clemson University, Clemson, SC.
>