Article View: can.construction
Article #140Re: Cooling attic (and home) by spraying water on roof (shingles)- good/bad?
From: Phil Scott
Date: Tue, 28 Jun 2005 23:05
Date: Tue, 28 Jun 2005 23:05
188 lines
6630 bytes
6630 bytes
"Chas Hurst" <hurst1@comcast.not> wrote in message news:pMGdnT7ZIrKcylzfRVn-2A@comcast.com... > > "Phil Scott" <philscott@philscott.net> wrote in message > news:d9quua$l83$1@news.tdl.com... > > > > "Chas Hurst" <hurst1@comcast.not> wrote in message > > news:0uednRz508PCbCLfRVn-1w@comcast.com... > > > Don't cooling towers use evaporative cooling? > > > > > > Yes they do... but they discharge 100% relative humidity > > air...but its outside so its fine...the water in the process > > is cooled and that cool water is used to cool most often the > > condensers on large tonnage refrigerated AC systems. that > > water typically runs 65 to 80 degrees F... sufficiently cool > > to cool condensers but not cool enough to be used directly for > > conditioning air (below 40F is required) > > > > Phil Scott > > Well you really lost me now. Hasn't this suggestion of water ON the roof > been about water on the outside of the house? > So the humidity created by a watered roof would be outside, just as with a > cooling tower. correct...thats why your plan WORKS....that is...it is VIABLE....in other words...you are NOT wrong.... said another way...your plan to cool the roof and thus reduce attic temps will fly like an eagle... its FLAWLESS.... to elaborate... water cooling works GREAT... your plan it water cooling the roof... very very good. Its just that an attic fan works better without whatever problems are incurred by wetting the roof...that is why so few people on planet earth, including the worlds best engineers use the strategy. Its workable you see.... just not practical in context with other approaches. Phil Scott > > Chas Hurst > > > > > > "Phil Scott" <philscott@philscott.net> wrote in message > > > news:d9ocdq$2hf$1@news.tdl.com... > > > > > > > > "Some Guy" <Some@Guy.com> wrote in message > > > > news:42BF3E57.659FD057@Guy.com... > > > > > Phil Scott wrote: > > > > > > > > > > > > Doesn't a mister waste water by atomizing it and > > then > > > > the > > > > > > > wind will blow it away? > > > > > > > > > > > > The latent heat of evaporation for water ... > > > > > > > > > > I still don't see an effective way to arrange a > > residential > > > > cooling > > > > > system based on the evaporation of water. > > > > > > > > > > I don't think you can concentrate and deliver a > > substantial > > > > amount of > > > > > heat to a surface you can cool via evaporation. > > Evaporative > > > > cooling > > > > > would be effective if the heat inside a house could be > > > > brought to an > > > > > out-door device who's surface temperature is well above > > > > boiling and > > > > > the application of water would result in evaporative > > > > cooling. > > > > > > > > > > > Evaporative cooling would be limitlessly popular if it > > > > > > did not add an equal amount of humidity in the form of > > > > > > 'steam' to the air it was cooling to *sensibly lower > > > > > > termperatures. > > > > > > > > > > So what you're saying is to mistify the air circulating > > in a > > > > house in > > > > > order to cool it. I don't think that would work once > > you've > > > > saturated > > > > > the air (ie humidity > 75%) not to mention the effects > > of > > > > saturated > > > > > air on items in the house, the wood, the machinery, etc. > > > > > > > > I am a mechancal engineer doing these sorts of > > calculations > > > > and systems for over 40 years.. and you are entirely > > correct > > > > if the humidity is say 50% and the outside air is 90F... > > you > > > > can cool the air to 75 or so but the humidity is then up > > into > > > > the 80% range and all the problems you mention manifest. > > > > Thats why evaportive cooling is not used in many cases. > > > > > > > > However in areas where the relative humidity is in the 20 > > to > > > > 30% range, and the outside air is over 90F... then the > > supply > > > > air can be cooled to 70F and 50% relative humidity..that > > works > > > > very well/ > > > > > > > > > > > > > > > > > > I think only the roof makes a workable item to cool with > > a > > > > water > > > > > cooling. It's designed to get wet, to collect runoff, > > and > > > > gets very > > > > > hot in the summer, and cooling it can lead to reduction > > in > > > > cooling > > > > > requirements of the house. > > > > > > > > Its workable...but there are problems ..its seldom > > used > > > > because of those problems. You get to do whatever you > > wish > > > > though its yer house. Have fun. > > > > > > > > > > > > > > > > > > The only thing that makes more sense is a temporary tarp > > or > > > > canopy to > > > > > cover the roof during the summer (to be taken down > > during > > > > nasty > > > > > weather, storms, etc). > > > > > > > > Oh please. > > > > > > > > > > > > Phil Scott > > > > > > > > > > > > > > > > > > > >
Technical Details
Message-ID:
<d9sl3b$vcc$1@news.tdl.com>Path:
arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!newshub.sdsu.edu!peer01.west.cox.net!cox.net!hwmnpeer01.phx!hwmedia!newsfeed1.easynews.com!easynews.com!easynews!news.he.net!news.tdl.com!not-for-mailReferences:
<42BDB7E5.456E1146@Guy.com> <jfOdnbddfPgDtSPfRVn-tQ@speakeasy.net> <orKdnX-MIND1ZiPfRVn-sQ@comcast.com> <42BF0BE3.2C314AE5@Guy.com> <d9nbt1$p8b$1@news.tdl.com> <42BF3E57.659FD057@Guy.com> <d9ocdq$2hf$1@news.tdl.com> <0uednRz508PCbCLfRVn-1w@comcast.com> <d9quua$l83$1@news.tdl.com> <pMGdnT7ZIrKcylzfRVn-2A@comcast.com>Show Full Headers
Complete Article Headers
X-Google-Thread: 104d3a,227127306d0081c2 X-Google-Thread: 10e8ea,227127306d0081c2 X-Google-Thread: fbbdb,227127306d0081c2 X-Google-Thread: 10fe96,227127306d0081c2 X-Google-Thread: f7551,227127306d0081c2 X-Google-Attributes: gid104d3a,gid10e8ea,gidfbbdb,gid10fe96,gidf7551,public X-Google-Language: ENGLISH,ASCII-7-bit Path: arc1-ca.pugleaf.net!g2news1.google.com!news3.google.com!newshub.sdsu.edu!peer01.west.cox.net!cox.net!hwmnpeer01.phx!hwmedia!newsfeed1.easynews.com!easynews.com!easynews!news.he.net!news.tdl.com!not-for-mail From: "Phil Scott" <philscott@philscott.net> Newsgroups: can.construction,alt.tv.hometime,alt.building.construction,alt.tv.home-imprvment,alt.home.automation Subject: Re: Cooling attic (and home) by spraying water on roof (shingles)- good/bad? Date: Tue, 28 Jun 2005 16:05:32 -0700 Organization: The Diamond Lane Lines: 190 Message-ID: <d9sl3b$vcc$1@news.tdl.com> References: <42BDB7E5.456E1146@Guy.com> <jfOdnbddfPgDtSPfRVn-tQ@speakeasy.net> <orKdnX-MIND1ZiPfRVn-sQ@comcast.com> <42BF0BE3.2C314AE5@Guy.com> <d9nbt1$p8b$1@news.tdl.com> <42BF3E57.659FD057@Guy.com> <d9ocdq$2hf$1@news.tdl.com> <0uednRz508PCbCLfRVn-1w@comcast.com> <d9quua$l83$1@news.tdl.com> <pMGdnT7ZIrKcylzfRVn-2A@comcast.com> NNTP-Posting-Host: o1-dialup-66-81-72-122.rev.o1.com X-Trace: news.tdl.com 1119999916 32140 66.81.72.122 (28 Jun 2005 23:05:16 GMT) X-Complaints-To: abuse@tdl.com NNTP-Posting-Date: Tue, 28 Jun 2005 23:05:16 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1506 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1506