psychrometric replaced by my spell checker with psychometric...sorry


"Smarty" wrote in message
...
trader4,

Your kind comments are very much appreciated. Because I am a retired
engineer and have worked with literally thousands of other engineers in my
career since the 1960's, I do especially dislike a simple technical matter
becoming complicated when it doesn't need to be, and a specific technical
question being answered with an unresearched and inappropriate answer. The
fellow at Villanova U. was asked about comparing humidistats, and replied
with clearly wrong information on a distantly related subject, and then
assumed the Honeywell could somehow magically infer outdoor temperature by
being mounted on an external wall even though it is clearly a cold air
return plenum mounted device with no physical proximity whatsoever to the
periphery of the house.

It doesn't take an engineering degree to know or use the equations he
mis-applies, and either psychometric charts or simple
spreadsheet/calculators are used by ASHRAE heating/cooling consultants and
contractors all the time to size these equipments.

I actually think the gentleman at MIT said it best when he corrected Nick
at Villanova by saying:

"Very wrong analysis. 312K Btu/day would evaporate almost 40 gallons of
water
per day (~8000 BTU/gallon). This is many times more than really
evaporated.
Savings are much smaller."

I apologized once before to this newsgroup for the digression and
confusion which arose, and do so once again now. I sincerely hope we can
get the original poster to be both well informed and fully comfortable
with the choice of a new humidifier and humidistat per his/her stated
inquiries.

Smarty










wrote in message
ups.com...
On Jun 13, 4:43 pm, "Smarty" wrote:
poster3814,

Your reply to the numerous comments from me and others never indicated
any
opinions or conclusions on your part as to which of the humidistat
approaches you prefer. As I imagine you are aware, both the Aprilaire and
the Honeywell humidifiers can be used with other humidistats, and in fact
the Aprilaire humidifier could be used with the Honeywell humidistat or
vice
versa. I bring this up because you may not be aware of this based on your
more recent thread, once again comparing Aprilaire to Honeywell.

In an earlier reply I did indeed make a mistake, and erroneously typed a
percent sign % when I intended to type a notation for degrees °. I think
it
was still apparent that my references to temperature and humidity of 70
and
30 respectively were pretty obvious despite the typo. Sorry for the wrong
keystroke.

Smarty

"poster3814" wrote in message

ink.net...



wrote:
Smarty wrote:

Since you think I am, to use your word, "bluffing", I will answer...
An order of magnitude drop in water / evaporation energy consumption
occurs when a corresponding order of magnitude drop in air leak takes
place (from 224 to 24)...

Wrong problem :-) I asked:

If your average US house naturally leaked 224 cfm on an average 30.4
F
Philadelphia January day with an outdoor humidity ratio wo = 0.0025,
how would the fuel consumption change if you

a) airsealed it to reduce the natural air leakage to 24 cfm, or

b) humidified it to 50%, with no airsealing?

but Smarty talks about airsealing WITH humidification, which isn't
needed,
given enough airsealing and natural indoor humidity sources like
people
and green plants, but let's solve the problems he poses...

For 70% indoor temp and 30% indoor humidity, you avoid evaporating
about
.09 gallons of water per day with the correspondingly tiny drop in
energy
consumption.

Smarty measures temperatures as percentages? :-) On my planet, 70 F
air
at 30% RH has a humidity ratio wi = 0.0047 pounds of water per pound
of
dry air, so keeping a 224 cfm house 70 F at 30% with an outdoor
humidity
ratio wo = 0.0025 requires evaporating 224x60x0.075(wi-wo) = 2.22
pounds
of water per hour or 53.2 pounds of water per day, ie 6.39 gallons.

A 24 cfm house requires 0.68 gallons per day, and the difference is
5.71 gallons, at an energy cost of 47.5K Btu/day, about 0.5 therms,
or $1/day at $2/therm.

Conversely, if you wanted to raise it to 50% humidity inside, you
need
more water / energy, the amount of which is again determined by what
initial indoor temperature and humidity you specify... I used 70% and
30% once
again, and, on this basis, see an ncrease of .15 gals of water to be
evaporated per day...

So Smarty is perfectly capable of providing different wrong answers
for the same 70F/30% problem :-)

... Enough of your nonsense!

*****Plonk*****

When a man is wrong and he won't admit it, he always becomes angry :-)
Nick

Thanks again for the replies. For what it's worth, I'm going to start a
new message thread that is somewhat related but not totally related.
--
Please respond to the newsgroup only. Email sent to this account goes
unread.- Hide quoted text -

- Show quoted text -


Heh, Smarty, just a side note. I didn't see your interchange with
the genius from Villanova until today. Just wanted to say, like
others here, I agree with you. He's well known for hijacking
threads. Someone asks a simple, practical, real world question and he
answers with equations and calcs trying to show how smart he is. But
in reality, all he shows is that he has a complete lack of practical
experience. He thinks because he has an equation, means it's
applicable to the question or that someone can re-engineer a 50 year
old house. The reality is, he couldn't even install a humidifier and
just gives V a bad reputation.