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dry environment and air conditioning
With the heat wave I have been using air conditioning for three days in a
row (central air). The relative humidity is now at 35% (too dry!!)and I am wondering if I should use a humidifier? The outside temperature is 41 celcius here in Southern Ontario. Thanks for any advise! M. |
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#2
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I seem to remember 50% relative humidity as a standard.
What about pans of water. I grew up in a Wisconsin house with radiators. filling specially constructed pans on top of the radiators was daily chore. TB |
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#3
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Montenegro wrote:
With the heat wave I have been using air conditioning for three days in a row (central air). The relative humidity is now at 35% (too dry!!)and I am wondering if I should use a humidifier? The outside temperature is 41 celcius here in Southern Ontario. Thanks for any advise! M. The problem is most humidifiers I have seen use some form of heat to help increase the humidity. You don't what that. What you may want is something like a swamp cooler that is often used in very dry areas. Somehow I doubt if that would be a great idea in the long run however. -- Joseph Meehan Dia duit |
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#4
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"Joseph Meehan" wrote in message ... Montenegro wrote: With the heat wave I have been using air conditioning for three days in a row (central air). The relative humidity is now at 35% (too dry!!)and I am wondering if I should use a humidifier? The outside temperature is 41 celcius here in Southern Ontario. Thanks for any advise! M. The problem is most humidifiers I have seen use some form of heat to help increase the humidity. You don't what that. What you may want is something like a swamp cooler that is often used in very dry areas. Somehow I doubt if that would be a great idea in the long run however. Agreed. Maybe he can raise his thermostat? Hey! 80 degrees at 35% humidity ought to be pretty comfortable..... |
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#5
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Dr. Hardcrab wrote:
"Joseph Meehan" wrote: Montenegro wrote: With the heat wave I have been using air conditioning for three days in a row (central air). The relative humidity is now at 35% (too dry!!)... Congratulations. You must have one of those fairly airtight Canadian houses. The problem is most humidifiers I have seen use some form of heat to help increase the humidity. You don't what that. What you may want is something like a swamp cooler that is often used in very dry areas. A portable swamp cooler would work, or increasing the AC airflow? There are lots of ways to increase the RH. Green plants, foutains in series with humidistats, indoor misters, damp basement floors... Agreed. Maybe he can raise his thermostat? Hey! 80 degrees at 35% humidity ought to be pretty comfortable..... The ASHRAE 55-2004 standard says 80 F at 55% would be comfortable. Nick |
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#6
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Very useful tips!
I am doing the 80 F at 55, and I am saving energy, sleeping better (not as cold as before!) ana having less problems of drying skin and dry nose and eyes. Thanks so much to all of you Montenegro "Montenegro" wrote in message .. . With the heat wave I have been using air conditioning for three days in a row (central air). The relative humidity is now at 35% (too dry!!)and I am wondering if I should use a humidifier? The outside temperature is 41 celcius here in Southern Ontario. Thanks for any advise! M. |
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#8
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Tony wrote:
The ASHRAE 55-2004 standard says 80 F at 55% would be comfortable. I can tell you from experience the past two weeks, that 80 degrees F at 55%-60% humidity feels much better than 76 degrees at 80% humidity The ASHRAE 55-2004 standard says you would be more comfy at 76/80. Nick 20 CLO = 1'clothing insulation (clo) 30 MET=1.1'metabolic rate (met) 40 WME=0'external work (met) 50 VEL=.1'air velocity 70 DEF FNPS(T)=EXP(16.6536-4030.183/(TA+235))'sat vapor pressure, kPa 80 DATA 80,57.5 90 DATA 78.707,80 100 FOR CASE = 1 TO 2 110 READ TA,RH 120 TA=(TA-32)/1.8 130 TR=TA 140 PA=RH*10*FNPS(TA)'water vapor pressure, Pa 150 ICL=.155*CLO'clothing resistance (m^2K/W) 160 M=MET*58.15'metabolic rate (W/m^2) 170 W=WME*58.15'external work in (W/m^2) 180 MW=M-W'internal heat production 190 IF ICL.078 THEN FCL=1+1.29*ICL ELSE FCL=1.05+.645*ICL'clothing factor 200 HCF=12.1*SQR(VEL)'forced convection conductance 210 TAA=TA+273'air temp (K) 220 TRA=TR+273'mean radiant temp (K) 230 TCLA=TAA+(35.5-TA)/(3.5*(6.45*ICL+.1))'est clothing temp 240 P1=ICL*FCL:P2=P1*3.96:P3=P1*100:P4=P1*TAA'intermed iate values 250 P5=308.7-.028*MW+P2*(TRA/100)^4 260 XN=TCLA/100 270 XF=XN 280 N=0'number of iterations 290 EPS=.00015'stop iteration when met 300 XF=(XF+XN)/2'natural convection conductance 310 HCN=2.38*ABS(100*XF-TAA)^.25 320 IF HCFHCN THEN HC=HCF ELSE HC=HCN 330 XN=(P5+P4*HC-P2*XF^4)/(100+P3*HC) 340 N=N+1 350 IF N150 GOTO 480 360 IF ABS(XN-XF)EPS GOTO 300 370 TCL=100*XN-273'clothing surface temp (C) 380 HL1=.00305*(5733-6.99*MW-PA)'heat loss diff through skin 390 IF MW58.15 THEN HL2=.42*(MW-58.15) ELSE HL2=0'heat loss by sweating 400 HL3=.000017*M*(5867-PA)'latent respiration heat loss 410 HL4=.0014*M*(34-TA)'dry respiration heat loss 420 HL5=3.96*FCL*(XN^4-(TRA/100)^4)'heat loss by radiation 430 HL6=FCL*HC*(TCL-TA)'heat loss by convection 440 TS=.303*EXP(-.036*M)+.028'thermal sensation transfer coefficient 450 PMV=TS*(MW-HL1-HL2-HL3-HL4-HL5-HL6)'predicted mean vote 460 PPD=100-95*EXP(-.03353*PMV^4-.2179*PMV^2)'predicted % dissatisfied 470 GOTO 490 480 PMV=99999!:PPD=100 490 PRINT TA,RH,PMV,PPD 500 NEXT CASE Temp (C) RH PMV PPD 26.66667 57.5 1.106953 30.83258 24.44445 80 .6077689 12.74688 25.94833 80 1.106916 30.83087 Innova AirTech Instruments has an excellent comfort web site... http://www.impind.de.unifi.it/Impind...va/thermal.htm |
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