Nick,

Your original reply to my one (and only) attempt by others on this newsgroup
to answer the stated question was dismissive, not at all to the point of how
the two humidistats compare, and digressive since it answered only the
question which you (yourself) posed...regarding water evaporation.

When I answered the original reply, you found it necessary to treat my
answer (which was directly on the poster's topic) in a sophomoric, pedantic,
and rude manner with your "I'll give you a hint" form of arrogance.

When I went to engineering school and for the 40 years thereafter, I was
taught to do research to solve a problem. A mere 90 seconds of research on
the poster's question revealed Honeywell's description and ads for the
Humidicalc duct-mounted humidistat.....clearly something incapable of making
any inference about external wall temperatures.

So now your reply, rather than addressing the topic is a personal attack. Is
name-calling part of what they teach at Villanova Computer and Electrical
Engineering School? It is very juvenile, and displays how angry and
embarrassed you truly are.

Smarty


wrote in message
...
Smarty wrote:

Nice try but a failing grade, Nick. Go to the back of the class.

No thanks, asshole :-) Then again, my two hints were insufficient for you?

The Honeywell Humidicalc is a duct mounted device, and does not use the
exterior walls in any way whatsoever.

http://electronicaircleaners.com/dat...ode=H1008A1008

Maybe clever Honeywell humidistats are mounted indoors on exterior
walls,
so they can get an idea of the outdoor temp, which would be colder with
a larger air-wall temp difference, but how would it know the wall or
window insulation values? It might get calibration help from an owner
who pushes a button when there is condensation.

So they have something like that button, in the "frost control" knob.
Maybe their patented Humidicalc software (what's the patent number?)
estimates the outdoor temp by the furnace duty cycle, ie the percentage
of time the duct air is more than (say) 120 F.

... How many min CFM do we need to keep a house RH 50% at 70 F with
an indoor humidity ratio wi = 0.00787 pounds of water per pound of dry air
when the outdoor humidity ratio wo = 0.0025 (Phila in January) and you and
your pint-a-day green plants naturally evaporate 1 gallon of water per
day?

Hint1: 8lb/24h = 60CFMx0.075(wi-wo).

Hint2: ASHRAE suggests 15 cfm of fresh air per full-time occupant.

Hint3: CFM = 8/24/60/0.075/(wi-wo) = 13.8.

Nick