re: is my new ac unit broken???
27 apr 2004
>...we are talking portable crapola humidifier.
>if hes in a muggy area to start with, all he will do is ad humidity to the
>room, and make the room feel overall warmer.
>> >portable evap coolers are one big waste of time and money.
>> i disagree, altho a house needs some outdoor airflow to make them work.
>i disagree strongly with you.
i double-dare disagree with you!
>in the right climate, like southern ca or arizona, up to about 58%rh
>they might work fine...
i've heard "50 f dew point" in az, but r&d vp gregg steinriede
at cool breeze of key west seems to be doing a good job...
>...unless you get a mc2, with the pre-coolers on it, and have either
>enough upducts in the home to move the air, or enough window and doors
>open to move that air right on out, all you do is create a warm, sticky place.
comfort zones don't care about brand names.
>> how much?
>how much what?
how much outdoor ventilation airflow do we need for comfort in a house
with a thermal conductance g btu/h-f and indoor humidification rate
p lb/h, given outdoor temp ta (f) and rh?
too little ventilation, and the indoor rh becomes 100%--uncomfortable.
too much, and indoor and outdoor air are the same--no improvement.
we just waste water and fan power.
if it's an average 88.2 f june day in phoenix with humidity ratio w = 0.0056
and a house has 200 btu/h-f of conductance and a 0.5 gph mister cool (tm)
nozzle indoors, how many cfm of ventilation is needed for comfort?
the 1992 ashrae 55 standard summer comfort zone has 4 corners with t (f)
and w at about (74,0.0045) [lower left--cool], (81,0.0045) [lower right],
(78.5,0.0122) [upper right--warm], and (72,0.0138) [upper left.] the upper
edge is w = -0.000246t+0.03152.
with c cfm of ventilation and no internal heat gain, the house above would
have an indoor temp t = 88.2-4000/(200+c) and w = 0.0056+4/(4.5c), which
meets the upper edge of the comfort zone when c = 122 cfm (not much), but
we can touch the upper right corner with less fan power and water usage
with c = 97 cfm and p = 2.9 vs 4 lb/h of water.
who makes an automatic controller to do that?