[Bldg-sim] [BLDG-SIM] earth-air exchanger (earth channels)

[Sam Mason]

All of our work for ground to air exchangers, or earth ducts, as well as
thermal labyrinths, has been completed using TRNSYS.

Sam

--
Sam Mason
Atelier Ten
sam.mason at atelierten.com
 
-----Original Message-----
From: bldg-sim-bounces at lists.onebuilding.org
[mailto:bldg-sim-bounces at lists.onebuilding.org] On Behalf Of Demba
Ndiaye
Sent: Monday, June 23, 2008 9:17 AM
To: near_ej at yahoo.com; Brian Fountain; bldg-sim at lists.onebuilding.org
Subject: Re: [Bldg-sim] [BLDG-SIM] earth-air exchanger (earth channels)

Neeraj, 

I recently modeled a ground-to-air heat exchanger using GAEA. You can
download a free trial version at WWW:  http://nesa1.uni-siegen.de/ . You
can import back the results into eQuest.

______________
Demba Ndiaye
> -----Original Message-----
> From: bldg-sim-bounces at lists.onebuilding.org [mailto:bldg-sim- 
> bounces at lists.onebuilding.org] On Behalf Of Neeraj Kapoor
> Sent: Monday, June 23, 2008 6:49 AM
> To: Brian Fountain; bldg-sim at lists.onebuilding.org
> Subject: Re: [Bldg-sim] [BLDG-SIM] earth-air exchanger (earth
channels)
> 
> Thanks Brian,
> 
> Looking up on the internet I came across a link that summarizes one
Dr.
> 
> Didier Thevenard's (of Numerical Logics Inc.) search carried out
online
> 
> and compiled together regarding this subject -- 
> http://www.emr.gov.yk.ca/energy/pdf/biblio_search_earth_tubes_v3_1.pdf
> -- It might be useful for folks who may want to propose / model 
> earth-air tunnel heat exchange (EATHE) systems.
> I am taking the liberty of posting the relevant part of your reply 
> (below), for the benefit of  everyone on the bldg-sim list.
> 
> sincerely,
> Neeraj
> 
> Brian Fountain wrote:
> > I too am just starting a project proposing the use of Earth Tubes.
> > Currently I am modeling in eQUEST as well and have not found a good 
> > way to model this system.
> >
> > I did run across the following article:
> > http://gundog.lbl.gov/dirpubs/SB06/kwangho.pdf
> > which describes an earth tube algorithm implemented in EnergyPlus.
> It
> > also describes parametric runs for 4 parameters (depth, diameter, 
> > velocity and length).  As yet, I have not tried this as I . . .
> > /[omitted text]./
> >
> > Good luck!
> >
> > Brian
> >
> > Neeraj Kapoor wrote:
> >> Hello everyone,
> >>
> >> I am trying to model Earth-Air tunnels in eQUEST located in a 
> >> tropical,composite climate (New Delhi). Following the last two 
> >> threads on this issue dated Nov. 2003 and Oct, 2006 (shown below) 
> >> nothing else seems to have been discussed, especially relating to 
> >> modeling this strategy in eQUEST? If anyone has had any experience 
> >> with it then please share. I'd appreciate your feedback. Meanwhile,

> >> let me try and explain the system that I am trying to model and how
> I
> >> am approaching it --
> >>
> >> Earth-air (horizontal) tunnels utilize 100% outside air as it is 
> >> blown through them. This brings down the temperature as the air is 
> >> sensibly pre-cooled for the air handling unit. In the hot-dry
months
> 
> >> the air is either delivered or is subjected to direct-indirect 
> >> evap-cooling. For warm-humid periods a small portion of the 
> >> pre-cooled air stream is subjected to DX coil where it drops most
of
> 
> >> its moisture and is mixed with the rest of the air stream In 
> >> principle my strategy will be to model ground-source heat exchanger
> >> (GSHX) wherein a fluid (water) rejects or gains heat and transfers 
> >> the benefit to the air handling unit using 100% OA. I am guessing 
> >> that the transfer of heat between water-earth via the GSHX and then

> >> water-air in the AHU has to be very efficient to diminish losses 
> >> incurred and model this system fairly accurately. I will finally 
> >> subtract the pumping energy from the total. Here is the crux, and
> the
> >> questions --
> >>
> >>    1. Am I thinking in the right direction?
> >>    2. How does one increase the efficiency of the GSHX process to
> best
> >>       reflect earth-air heat exchange? The aim as I said earlier is
> to
> >>       diminish the losses incurred due to the water-earth and
> >>       water-air processes of the GSHX?
> >>
> >> For now, I am tied to eQUEST to solve this problem because a large 
> >> time-consuming part of the model is already accomplished. However
if
> 
> >> there is a better way to address this with any other tool then
> please
> >> do not shy from sharing your knowledge. Many thanks for helping in 
> >> the past and in advance on this one.
> >>
> >> sincerely,
> >> Neeraj
> >>
> >> Neeraj Kapoor
> >> t: +91-99581.70018
> >> Kalpakrit Sustainable Environments Pvt. Ltd.
> >> New Delhi
> >>
> >> ---------------
> >> Victor Hanby wrote:
> >>
> >>> >
> >>> > On 31 Oct 2006, at 10:07, Yatin Choudhary wrote:
> >>> >
> >>>
> >>>> >>
> >>>> >> hi every one
> >>>> >> i am trying to simulate a type 56 with earth air tunnel
> hypocast
> >>>>
> >> ,...
> >>>> >> want
> >>>> >> to compare with a 1.5 TR window unit ac please advise
> >>>> >>
> >>>> >>
> >>>> >> ======================================================
> >>>> >> You received this e-mail because you are subscribed
> >>>> >> to the BLDG-SIM at GARD.COM mailing list.  To unsubscribe
> >>>> >> from this mailing list send a blank message to
> >>>> >> BLDG-SIM-UNSUBSCRIBE at GARD.COM
> >>>> >>
> >>>>
> >>> >
> >>> > Dr Farraj Al-Ajmi pretty much did this for his PhD studies at >
> >>> Loughborough University (UK). It's described in
> >>> >
> >>> > Al-Ajmi, F., D.L.Loveday and V.I.Hanby 2006 ``The cooling
> potential
> >>>
> >> of
> >>> > earth-air heat exchangers for domestic buildings in a desert
> >>>
> >> climate''
> >>> > Building and Environment 41:235--244.
> >>> >
> >>> > and
> >>> >
> >>> > Hanby, V.I., F.Al-Ajmi and D.L.Loveday 2004 ``The optimal design
> for
> >>>
> >> a
> >>> > ground cooling tube in a hot, arid climate''  Building Services
>
> 
> >>> Engineering Research and Technology 26(1):1--10.
> >>> >
> >>> > Farraj wrote TYPES for the ground cooling tube and the subsoil >
> >>> environment. I've lost touch with him but I think he has posted
> here
> >>> > in the past. He might be able to help you with some code. I
> >>> modeled > the ac unit sing a fixed temperature approach for each
> >>> coil > (evaporator and condenser) then assumed a fixed fraction of
> >>> Carnot to
> >>>
> >>
> >>
> >>> > get the energy consumption.
> >>> >
> >>> > Vic Hanby
> >>> >
> >>> > -----------------------------------------------
> >>> > Professor V I Hanby
> >>> > Institute of Energy and Sustainable Development
> >>> > De Montfort University
> >>> > The Gateway
> >>> > Leicester LE1 9BH
> >>> > UK
> >>> > ------------------------------------------------
> >>> >
> >>> >
> >>> > ======================================================
> >>> > You received this e-mail because you are subscribed to the >
> >>> BLDG-SIM at GARD.COM mailing list.  To unsubscribe from this mailing
> >>>
> >> list
> >>> > send a blank message to BLDG-SIM-UNSUBSCRIBE at GARD.COM
> >>>
> >>
> >>     * /To/: <BLDG-SIM at xxxxxxxx <mailto:BLDG-SIM at DOMAIN.HIDDEN>>
> >>     * /Subject/: [BLDG-SIM] earth-air exchanger (earth channels)
> >>     * /From/: Denis Bourgeois <denis.bourgeois at xxxxxxxxxxxxx
> >>       <mailto:denis.bourgeois at DOMAIN.HIDDEN>>
> >>     * /Date/: Fri, 21 Nov 2003 15:27:36 -0500
> >>     * /List-unsubscribe/: <mailto:BLDG-SIM-Unsubscribe at gard.com>
> >>     * /References/:
> >>       <MDAEMON-F200311201548.AA4849171pd80000629044 at xxxxxxxx
> >>
> >>
<mailto:MDAEMON-F200311201548.AA4849171pd80000629044 at DOMAIN.HIDDEN>>
> >>       <MDAEMON-F200311211204.AA0424687pd80000630311 at xxxxxxxx
> >>
> >>
<mailto:MDAEMON-F200311211204.AA0424687pd80000630311 at DOMAIN.HIDDEN>>
> >>     * /Reply-to/: denis.bourgeois at xxxxxxxxxxxxx
> >>       <mailto:denis.bourgeois at DOMAIN.HIDDEN>
> >>     * /Sender/: postman at xxxxxxxx <mailto:postman at DOMAIN.HIDDEN>
> >>
> >>
>
------------------------------------------------------------------------
> >> Bonjour Hugues,
> >>
> >> I'm unaware of any single program that automatically sets this up.
A
> 
> >> very discrete finite-... 3D conduction model would be desirable,
but
> 
> >> depending on your specific needs, ESP-r would be a very good
> >> candidate as an annual assessment tool. I've used ESP-r for
> >> underground air culvert assessment in the past and a couple of
> >> graduate students have used ESP-r for similar studies (Y. Jeong, a
> >> grad student at Concordia, and another student in Norway (a PhD
> >> student I believe) have both used ESP-r for assessing the Media
> >> School in Norway, which has an
> >> underground air culvert).
> >>
> >> In Jeong's case, the culvert is modeled as one zone, but it is
> fairly
> >> straightfoward in ESP-r to subdivide this in, let's say, 10 zones
> >> (e.g., a 40m culvert could be made up of ten 4m segments) - that's
> >> what I do. This will give you a more detailed assessment, e.g., of
> >> culvert surface
> >>
> >> temperatures along the airflow path (useful for condensation
> assessment
> >>
> >> or to see just how effective the first segments of the culvert are
> in
> >> relation to the last ones). ESP-r also allows you to set up an
> >> airflow network, but 'scheduled' airflows might be OK for your
> needs.
> >>
> >> The main challenge is setting up the surface boundary conditions.
> >> Without setting up a 3D conduction model in ESP-r (available, but
> not
> >> for the faint-hearted), you'll have to specify boundary conditions
> >> for each surface. If the culvert is deep enough,
> >> you can just feed it monthly ground profiles for ~ of the surfaces,
> 
> >> with harmonics calculated with standard models (see Maitos and
> >> Argiriou) - the same models used for ground-coupled heat pump
> >> simulation. If it's deep enough, the daily variations will be minor
> >> (~ 1C during the course of a month). The remaining ~ of the
> >> surfaces will more likely feel the effect of the nearby ground
> >> surface, so ambient air might be more suitable as a surface
boundary
> 
> >> condition. If the culvert is very close to the ground surface, then
> >> it's a bit more tricky - maybe ~ of the surfaces need ambient air
> as
> >> a boundary condition. You can of
> >> course 'tweak' the model to see just how sensible it is to variable
> >> changes.
> >>
> >> Another point is setting up the right surface element
> 'constructions'
> >> so on one hand it remains numerically stable, and on the other the
> >> constructions remain 'thick' enough so that using monthly profiles
> >> remains valid (at least conceptually).
> >>
> >> Transsolar have modeled culverts for other energy consultants in
the
> 
> >> past - maybe they've set up some basic modeling approach in TRNSYS
> (?).
> >>
> >> Simpler empirical approaches are available: Argiriou and Maitos
give
> an
> >>
> >> overview of existing models found in the literature.
> >>
> >> Good luck,
> >>
> >> ----
> >>
> >> Some references:
> >>
> >> Jeong, Y., and Haghighat, F. (2002) "Modeling of a hybrid
ventilated
> 
> >> building, Grong School" /Proceedings of the 4th International Forum
> >> on Hybrid Ventilation: An Integrated Solution for Ventilation,
> Health
> >> and Energy/, Montreal pp.198-207.
> >>
> >> Maitos, A. (1999) "Cooling with underground air ducts" MSc Thesis.
> >> University of Strathclyde: Glasgow. 68p.
> >>
> >> Argiriou, A.A. (1996) "Ground cooling" in /Passive Cooling of
> >> Buildings/. M.J. Santamouris and D.N. Asimakopoulos, eds., James &
> >> James: London. pp.360-403.
> >>
> >> Kumar, R., Ramesh, S., and Kaushik, S.C. (2003) "Performance
> evaluation
> >>
> >> and energy conservation potential of earth-air-tunnel system
coupled
> 
> >> with non-air-conditioned building" /Building and Environment/ 38
> >> pp.807-813.
> >>
> >> Lay, R.M. (2003) "Earth Rangers Wildlife Centre - case study of
> >> concrete use for energy efficiency" /Proceedings of the 8th
> >> Environmental and Sustainable Engineering Specialty Conference of
> the
> >> Canadian Society
> >> for Civil Engineering/, Moncton.
> >>
> >> Sawhney, R.L., Buddhi, D., and Thanu, N.M. (1999) "An experimental
> >> study of summer performance of a recirculation type underground
> >> airpipe air conditioning system" /Building and Environment/ 34(2)
> >> pp.189-196.
> >>
> >> ----
> >>
> >> Denis Bourgeois
> >> PhD student/doctorant
> >> cole d'architecture, Universit Laval
> >> denis.bourgeois at xxxxxxxxxxxxx
<mailto:denis.bourgeois at xxxxxxxxxxxxx>
> >>
> >> ----
> >>
> >>     ----- Original Message -----
> >>     *From:* Hugues Boivin <mailto:huguesboivin at xxxxxxxxxxxx>
> >>     *To:* BLDG-SIM at xxxxxxxx <mailto:BLDG-SIM at xxxxxxxx>
> >>     *Sent:* Friday, November 21, 2003 1:11 PM
> >>     *Subject:* [BLDG-SIM] earth-air exchanger (earth channels)
> >>
> >>     Does anyone knows a simulation tool to evaluate energy savings
> by
> >>     earth-to-air exchanger (earth channels) ?
> >>          Thank you.
> >>                    Hugues Boivin
> >>     Mechanical Engineer
> >>     Laval University
> >>     GRAP (Groupe de recherche en ambiance physique)
> >>
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