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<DIV><FONT color=#0000ff>My comments in blue. </FONT></DIV>
<DIV><FONT color=#0000ff></FONT> </DIV>
<DIV style="DISPLAY: inline; FONT-FAMILY: ; COLOR: ; TEXT-DECORATION: ">
<DIV><FONT face=Calibri><FONT style="FONT-SIZE: 12pt">Christian Corson
writes:</FONT></FONT></DIV></DIV>
<DIV>
<DIV style="DISPLAY: inline; FONT-FAMILY: ; COLOR: ; TEXT-DECORATION: "><FONT
face=Calibri><FONT style="FONT-SIZE: 12pt">Buy a single ASHP and call it good.
3/4 ton will get it done. Install it yourself and save a G. $1600.00 bucks and a
lifetime of heating/cooling and de-humidification. </FONT></FONT></DIV>
<DIV>Done and done.</DIV>
<DIV></DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV><FONT color=#0000ff size=4 face="Times New Roman">An air sourced heat pump
is the off the shelf predictable performance way to cool and dehumidify a house.
I do speck these mini split heat pumps on houses for my clients. However, they
still have the problem of using refrigerants that are never supposed to leak.
With the vast amount of refrigerant cooling done, incrementally there is steady
leaking going on. Also, depending on a proprietary machine such as the
Mitsubishi Mr Slim Mini Split System depends on an international supply chain
and dependence on a single company for support. If either of these conditions is
interrupted the system suffers or fails. What I propose is a simpler technology
using desiccant in a box with a humidity switch to a fan blows indoor air
through between above 50%RH. </FONT></DIV></DIV>
<DIV><FONT color=#0000ff></FONT> </DIV>
<DIV><FONT color=#0000ff></FONT> </DIV>
<DIV><FONT color=#0000ff>It took some concentration to work through Nick’s
numbers. They are certainly thought provoking. </FONT></DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV>-----Original Message----- </DIV>
<DIV>From: nick pine </DIV>
<DIV>Sent: Monday, September 24, 2012 5:31 PM </DIV>
<DIV>To: greenbuilding@lists.bioenergylists.org </DIV>
<DIV>Subject: Re: [Greenbuilding] Dessiccant Potential </DIV>
<DIV> </DIV>
<DIV>"Eli Talking" <elitalking@rockbridge.net> wrote:</DIV>
<DIV> </DIV>
<DIV>>I have been intrigued by the idea of using heat to recharge (dry out)
</DIV>
<DIV>>desiccant to be used to adsorb humidity within a space.</DIV>
<DIV> </DIV>
<DIV>Me too.</DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV> </DIV>
<DIV>>Since I live in a wooded setting, the active solar opportunities are
</DIV>
<DIV>>limited for recharging the desiccant.</DIV>
<DIV> </DIV>
<DIV>Dry air can be transported farther than warm or cool air...</DIV>
<DIV><FONT color=#0000ff size=4>What do you mean by that?</FONT></DIV>
<DIV><FONT color=#0000ff size=4></FONT> </DIV>
<DIV>I just posted this on the yahoo solar heat list, regarding a new 1800 ft^2
</DIV>
<DIV>house in Florida:</DIV>
<DIV> </DIV>
<DIV>>... r32.5 of foam under roof. Walls are roughly 1700 sqft... about an
R14.</DIV>
<DIV>Windows and door along exterior walls is roughly 325 sqft. I think an R-1.5
</DIV>
<DIV>can</DIV>
<DIV>be assumed to be minimum for those areas.</DIV>
<DIV> </DIV>
<DIV>That's 1800ft^2/R32.5 = 55 Btu/h-F + 1700/14 = 121 + 325/1.5 = 217,
totaling</DIV>
<DIV>393. Or less, with lower window and wall conductances :-)</DIV>
<DIV> </DIV>
<DIV>>Being mostly masonry house not much leakage. Not leakage in walls, only
</DIV>
<DIV>>windows</DIV>
<DIV>and doors. If I pay attention to their install be very tight house.</DIV>
<DIV> </DIV>
<DIV>Maybe 0.1 ACH, ie 0.1x1800ft^2x8'/60 = 24 cfm, making the total
thermal</DIV>
<DIV>conductance be <FONT style="BACKGROUND-COLOR: #ffff00">417</FONT>
Btu/h-F.</DIV>
<DIV> </DIV>
<DIV><FONT color=#0000ff>Where does 417 btu/hrF come from?</FONT></DIV>
<DIV><FONT color=#0000ff></FONT> </DIV>
<DIV><FONT color=#0000ff>Is .1ACH enough. Using the ASHRAE
formula </FONT></DIV>
<TABLE style="BORDER-COLLAPSE: collapse; COLOR: #000000" border=0 cellSpacing=0
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width=233></FONT>
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<TD
style="PADDING-LEFT: 1px; PADDING-RIGHT: 1px; VERTICAL-ALIGN: bottom; PADDING-TOP: 1px"
class=xl67 height=20 width=233><FONT face=Calibri><FONT
color=#0000ff><SPAN style="mso-spacerun: yes"><FONT
style="FONT-SIZE: 11pt"> </FONT></SPAN><FONT
style="FONT-SIZE: 11pt">Requred ventialtion/min =(.01cfm/sf Area(sf)) +
(7.5cfm/occupant x #occupants)</FONT></FONT><SPAN
style="mso-spacerun: yes"><FONT
style="FONT-SIZE: 11pt"> </FONT></SPAN></FONT></TD></TR></TBODY></TABLE>
<DIV><FONT size=4></FONT> </DIV>
<DIV>>>NREL says 1730 Btu/ft^2 of sun falls on the ground on an average
82.1 F </DIV>
<DIV>>>August</DIV>
<DIV>day with a 74.5 low and a 0.0175 humidity ratio in August in Tampa. <FONT
color=#0000ff>(Average?)</FONT> The deep</DIV>
<DIV>ground temp is <FONT style="BACKGROUND-COLOR: #ffff00">72.3</FONT>. ASHRAE
says an 80 F house with a 0.120 humidity ratio </DIV>
<DIV>can</DIV>
<DIV>be comfortable.</DIV>
<DIV> </DIV>
<DIV><FONT color=#0000ff size=4>What is your source of information for average
humidity ratio for August?</FONT></DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV><FONT color=#0000ff>Where in ASHRAE is reference to humidity and
comfort?</FONT></DIV>
<DIV> </DIV>
<DIV>With 600 kWh/mo of indoor electrical use, ie 2843 Btu/h, the house only
</DIV>
<DIV>needs</DIV>
<DIV>(82.1-80)<FONT style="BACKGROUND-COLOR: #ffff00">417</FONT> + 2843 = <FONT
style="BACKGROUND-COLOR: #ffff00">3719</FONT> Btu/h of cooling on an average
August day.</DIV>
<DIV> </DIV>
<DIV>> We are going to have radiant ceiling.</DIV>
<DIV> </DIV>
<DIV>The cooling could come from <FONT
style="BACKGROUND-COLOR: #ffff00">3719</FONT>/(80-<FONT
style="BACKGROUND-COLOR: #ffff00">72.3</FONT>)/8.33/60 = 1 gpm of 72.3 F
water</DIV>
<DIV>moving through the ceiling, or less, with a smaller house
conductance.</DIV>
<DIV><FONT color=#0000ff>I see you are subtracting the ground temp from 80F
comfort conditions. How do you propose to do this?</FONT></DIV>
<DIV> </DIV>
<DIV>If occupants evaporate 2 gallons per day of water and air leaks add</DIV>
<DIV>24hx24cfmx60m/hx0.075lb/ft^3(0.0175-0.0120) = 14 lb, the house needs 31
</DIV>
<DIV>lb/day of dehumidification. </DIV>
<DIV> </DIV>
<DIV><FONT color=#0000ff size=4>What is your source of infomration on 2gal/day
evaporation from occupants?</FONT></DIV>
<DIV><FONT color=#0000ff size=4></FONT> </DIV>
<DIV><FONT color=#0000ff size=4>.0120 is the humidity ratio for 80F at 55%RH
according to psychrometric chart. </FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV>FSEC is exploring solar-dried bentonite clay clumping </DIV>
<DIV>cat litter,</DIV>
<DIV>which can absorb about 20% of its weight in a daily cycle, so the house
</DIV>
<DIV>could have</DIV>
<DIV>150 lb of clay in a glazed box on the roof.</DIV>
<DIV> </DIV>
<DIV><A
title=http://www.grace.com/engineeredmaterials/MaterialSciences/SilicaGel/SilicaGelTypes/SilicaGelTypeAdsorption.aspx
href="http://www.grace.com/engineeredmaterials/MaterialSciences/SilicaGel/SilicaGelTypes/SilicaGelTypeAdsorption.aspx">http://www.grace.com/engineeredmaterials/MaterialSciences/SilicaGel/SilicaGelTypes/SilicaGelTypeAdsorption.aspx</A></DIV>
<DIV><FONT color=#0000ff size=4>This chart shows the Silica Gel can adsorb 40%
humidity of weight at 80%RH air and 26%weight at 50%RH</FONT></DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV>Who needs AC? :-)</DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV><FONT size=4><FONT color=#0000ff>Sensible cooling can be achieved with
daily temp swing averaging. However, removing the humidity is the
key. Desiccants can do that where any kind of heat is used to recharge
(dry) the desiccant.</FONT> </FONT></DIV>
<DIV><FONT size=4></FONT> </DIV>
<DIV><FONT color=#0000ff size=4>Eli </FONT></DIV>
<DIV> </DIV>
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