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Recommendations and advice for Humidifier connected to Furnace !

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Supahhh wrote: more than that.
yes thats useless too since it has many other factors which the doctor knows to take into account when making recommendations. this doesn't have any science backing it.
Are you being serious? The chart definitely has science behind it (probably classified under thermodynamics, but it's such a basic concept, it might be considered "general science), and that science is closely related to dew point, and is easily observable in your home.

The fact is, the surface temperature near your walls and windows (notably the latter) is measurably cooler than the temp in your house (no matter how good your windows are). While the provided chart is obviously an approximation of an average home, it is not without scientific base, as you claim. You might've learned about dew point in grade school; not why it is (these concepts being beyond an average gr. 7 student's comprehension), but how it's calculated using pre-established psychrometric charts. Those charts are created using various types of science, but it is pretty observable with basic tests (which is why it's done in grade school, at least mine, and my school was quite basic).

Maybe in your specific home, when it's -20°C outside, you can get away with 28% RH, but it's close enough that general variances (airflow namely, but also your guess of the outdoor temp. as well, among other factors) will make the chart "accurate enough". Much like an "ideal weight" chart, which is also very obviously not useless (note: it's an ideal weight range chart, and comes with the caveat that you're an average person, not a peak-performance athlete, or a sedentary quadriplegic ... both of which would obviously have "side-case" ideals).

Sounds like you don't understand the concept of these recommendations being representative of an average situation. Most people have a hard time doing their taxes (which is adding and subtracting), so having an equation on their humidistat with 25 variables that they have to solve for to know where to set their humidity at? Obviously unrealistic.
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Supahhh wrote: more than that.
yes thats useless too since it has many other factors which the doctor knows to take into account when making recommendations. this doesn't have any science backing it.
The height/weight chart isn't useless, do you have a medical PhD to make these assumptions? Also for Relative Humidity and the chart it does have science backing it:
https://www.ashrae.org/technical-resour ... -occupancy

I'm not trying to personally attack you, but I'm posting this information so people reading this thread can make an informed decision. It seems you constantly post opinionated information with only your opion on matters backing it. Spreading personal opinion doesn't make it fact... Many people in this thread have posted the correct info that can be backed up and researched further.
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ChubChub wrote: Are you being serious? The chart definitely has science behind it (probably classified under thermodynamics, but it's such a basic concept, it might be considered "general science), and that science is closely related to dew point, and is easily observable in your home.

The fact is, the surface temperature near your walls and windows (notably the latter) is measurably cooler than the temp in your house (no matter how good your windows are). While the provided chart is obviously an approximation of an average home, it is not without scientific base, as you claim. You might've learned about dew point in grade school; not why it is (these concepts being beyond an average gr. 7 student's comprehension), but how it's calculated using pre-established psychrometric charts. Those charts are created using various types of science, but it is pretty observable with basic tests (which is why it's done in grade school, at least mine, and my school was quite basic).
ideals).
vrscdx wrote: The height/weight chart isn't useless, do you have a medical PhD to make these assumptions? Also for Relative Humidity and the chart it does have science backing it:
https://www.ashrae.org/technical-resour ... -occupancy
So .... where is it? really?

I mean for such a widely disseminated chart, the science must be really clear right ?
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Supahhh wrote: So .... where is it? really?

I mean for such a widely disseminated chart, the science must be really clear right ?
Clear to people who have the prerequisite knowledge of reasonably basic science? yes. The science behind how they determine fuel's octane is also based on math (chemistry, primarily), but likely that science is also not understood by you. I also doubt you have knowledge of how to calculate lift on an airplane wing, but that doesn't mean they're randomly putting stuff in a wind-tunnel and hoping for the best, they're using "science" (in this case, for lift specifically, it would be L = Cl * A * .5 * r * V^2 ... though giving you the "final answer" is similar to giving you that chart, which you don't accept as proof).

So yes, it is clear, just seemingly not to you. If you're looking for the science required to understand where that chart came from, I suggest going to the library and scooping up a Thermodynamics book (I personally have McGraw-Hill's Thermodynamics: An Engineering Approach; it's pretty basic by Thermo standards, especially since it's geared towards engineers, but it does provide the groundwork to understand that chart, and skips the more complex concepts). If the material that book expects as previously understood knowledge is foreign to you, you should pickup a highschool "science" book (grade 9-10, in the "academic" stream), or maybe physics. If that is not understood, then a gr 7-8 science book would be the starting point. Those books will progressively get you closer and closer to having the requisite knowledge to create that chart.

Do you just want to know where that (admittedly VERY simplified) chart comes from? It's this equation:
omega_phi.gif
.

It assumes constant enthalpy (among other constants, which are nearly endless if you really want ... like this equation doesn't work if air temps are so high it's turning into plasma ... etc). Where does that equation come from? Well, those books I mentioned first of all (aka: the body of science by which most of our scientific advancements are based upon) , but also these guys: ASHRAE ... in case you're curious about their credentials, they've been around (as an entity) since the 1800s.

However, as should be reasonably obvious from the chart, it follows a very basic pattern that matches many charts of this type. And it should be reasonably obvious that the chart wasn't randomly created, otherwise it would have no applicable use.

Edit: I guess if you want an absolutely basic (as in, just a description of the science of humidity), you can just go to the Pyrochrometrics Wikipedia Page
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ChubChub wrote: Clear to people who have the prerequisite knowledge of reasonably basic science? yes. The science behind how they determine fuel's octane is also based on math (chemistry, primarily), but likely that science is also not understood by you. I also doubt you have knowledge of how to calculate lift on an airplane wing, but that doesn't mean they're randomly putting stuff in a wind-tunnel and hoping for the best, they're using "science" (in this case, for lift specifically, it would be L = Cl * A * .5 * r * V^2 ... though giving you the "final answer" is similar to giving you that chart, which you don't accept as proof).

So yes, it is clear, just seemingly not to you. If you're looking for the science required to understand where that chart came from, I suggest going to the library and scooping up a Thermodynamics book (I personally have McGraw-Hill's Thermodynamics: An Engineering Approach; it's pretty basic by Thermo standards, especially since it's geared towards engineers, but it does provide the groundwork to understand that chart, and skips the more complex concepts). If the material that book expects as previously understood knowledge is foreign to you, you should pickup a highschool "science" book (grade 9-10, in the "academic" stream), or maybe physics. If that is not understood, then a gr 7-8 science book would be the starting point. Those books will progressively get you closer and closer to having the requisite knowledge to create that chart.

Do you just want to know where that (admittedly VERY simplified) chart comes from? It's this equation: omega_phi.gif.

It assumes constant enthalpy (among other constants, which are nearly endless if you really want ... like this equation doesn't work if air temps are so high it's turning into plasma ... etc). Where does that equation come from? Well, those books I mentioned first of all (aka: the body of science by which most of our scientific advancements are based upon) , but also these guys: ASHRAE ... in case you're curious about their credentials, they've been around (as an entity) since the 1800s.

However, as should be reasonably obvious from the chart, it follows a very basic pattern that matches many charts of this type. And it should be reasonably obvious that the chart wasn't randomly created, otherwise it would have no applicable use.

Edit: I guess if you want an absolutely basic (as in, just a description of the science of humidity), you can just go to the Pyrochrometrics Wikipedia Page
All that is only just saying exactly what Ive been saying all along. Its "natural humidity" of outdoor air when brought indoors and raised in temperature. So what makes its different from a simple translation of outdoor humidity? to what indoor humidity *should* be.

I mean really, it should be obvious to anyone who looks at the chart. 15% humidity is an uncomfortable humidity. Not to mention it will cause shrinkage in your house wood.
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Supahhh wrote: All that is only just saying exactly what Ive been saying all along. Its "natural humidity" of outdoor air when brought indoors and raised in temperature. So what makes its different from a simple translation of outdoor humidity? to what indoor humidity *should* be.
I have no idea what this is trying to say.
Supahhh wrote: I mean really, it should be obvious to anyone who looks at the chart. 15% humidity is an uncomfortable humidity. Not to mention it will cause shrinkage in your house wood.
Uncomfortable and shrinkage ... or possible mould. Not hard to choose which.
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pootza wrote: I have no idea what this is trying to say.
This
Supahhh wrote: A long time ago i looked into this and I came across some details regarding how winter temperatures were regulated in rental units . but the humidity levels were not adjusted/ recommended in that. eventually municipalities suggested humidity levels which were pretty much the "natural humidity levels " for the temperature. i,e If you have air outside at 0 Degrees with 50% humidity, when you bring that air inside and heat it to 20C, the humidity in that air would drop to 25%. That is the reality of the "recommended" Humidity.

pootza wrote: Uncomfortable and shrinkage ... or possible mould. Not hard to choose which.
The Entire Field of HVAC is for people to live comfortably. and Well houses are build for people to live in comfortably. So if you're having mould issues, then its a construction quality issue. Not a humidity issue.

Here is an example;

Patient to doctor ; my child has stuffy noses and is having trouble breathing at night.
Doctor: try raising the humidity in the house.
Customer to Windows Contractor: I have condensation on my windows
Contractor: Here is a chart of recommended Humidity. follow that and you will have no problems.

The above conversation to me suggests that the Windows are deficient and contractor is dodging responsibility.

Here is some more;
In cold climates, the outdoor temperature causes lower capacity for water vapor to flow about. Although it may be snowing and the relative humidity outdoors is high, once that air comes into a building and heats up, its new relative humidity is very low (meaning the air is very dry), which can cause discomfort. Dry cracked skin can result from dry air.

Low humidity causes tissue lining nasal passages to dry, crack and become more susceptible to penetration of Rhinovirus cold viruses.[10] Low humidity is a common cause of nosebleeds. The use of a humidifier in homes, especially bedrooms, can help with these symptoms.[11]

Indoor relative humidities should be kept above 30% to reduce the likelihood of the occupant's nasal passages drying out.[12][13]

Humans can be comfortable within a wide range of humidities depending on the temperature—from 30–70%[14]—but ideally between 50 %[15] and 60 %.[16] Very low humidity can create discomfort, respiratory problems, and aggravate allergies in some individuals. In the winter, it is advisable to maintain relative humidity at 30% or above.[17] Extremely low (below 20 %) relative humidities may also cause eye irritation.[12][18]
So next winter when you have the flu, blame the window contractor who told you to put the humidity low and this chart,
vrscdx wrote: The height/weight chart isn't useless, do you have a medical PhD to make these assumptions? Also for Relative Humidity and the chart it does have science backing it:
https://www.ashrae.org/technical-resour ... -occupancy
I looked into it from a ASHRAE point of View. ASHRAE doesnt specify a lower limit.

Thats saying something to me about it. You might make your own deductions.
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Supahhh wrote: The Entire Field of HVAC is for people to live comfortably. and Well houses are build for people to live in comfortably. So if you're having mould issues, then its a construction quality issue. Not a humidity issue.
That statement is about as useless as the height/weight chart. If you had poor construction the outside cooler/drier -20C air would infiltrate the house and the humidity level would go down not go up. The humidity would be generated from the people and their activities ... not from construction.
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pootza wrote: That statement is about as useless as the height/weight chart. If you had poor construction the outside cooler/drier -20C air would infiltrate the house and the humidity level would go down not go up. The humidity would be generated from the people and their activities ... not from construction.
Thats exactly it. Outside air is not drier until it enters the house. Thats exactly what the chart is saying.

The Chart is De-humidification chart. So if you have single pane glass, the inside humidity is held low to prevent fogging ( if you're still living in the 1920s and want to prevent fogging on the single pane windows you would want to follow the chart and hold the Inside humidity low).

However Single pane performance is a pretty low bar. So if you have a double pane glass and its fogging up with a higher humidity than the chart. the culprit is that the pane's performance is now equal to a Single pane glass.

Similarly the House should not have any surface which directly transitions to the outside temperature. if it does, its a construction fault.
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Supahhh wrote: Thats exactly it. Outside air is not drier until it enters the house. Thats exactly what the chart is saying.
That's not what he posted nor what the chart says.
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Zamboni wrote: That's not what he posted nor what the chart says.
Ok lets start from the begining.
Supahhh wrote: A long time ago i looked into this and I came across some details regarding how winter temperatures were regulated in rental units . but the humidity levels were not adjusted/ recommended in that. eventually municipalities suggested humidity levels which were pretty much the "natural humidity levels " for the temperature. i,e If you have air outside at 0 Degrees with 50% humidity, when you bring that air inside and heat it to 20C, the humidity in that air would drop to 25%. That is the reality of the "recommended" Humidity.
When air is outside, Its humid at 50%( about), the same air when its brought inside and its temperature raised becomes dry.
The Chart translates those numbers presents it as a chart.
The theory being, If you have a single pane glass, If your inside air touches the glass it wont fog up since its at the same level as outside and it wont condense.

( this is useless from a human perspective . its as good as having no control except dehumidification. Because any humidification will result in fogging of single pane windows. )

Also a Single pane window has a insulation value of about 0.7- 0.9 where as modern ( Suspended film )Windows are able to achieve an R value of 20. So this chart is (Ive already said it many times.)
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i have honeywell whole house humidifier attached to furnace. it was hooked to hot water before using saddle valve, so to get rid of leaking saddle valve i hooked it up to cold water pipe using ball valve. i started seeing gaps in my wooden floor too. my humidity is set to 40% but nest only shows around 31-35%.
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brampton90 wrote: i have honeywell whole house humidifier attached to furnace. it was hooked to hot water before using saddle valve, so to get rid of leaking saddle valve i hooked it up to cold water pipe using ball valve. i started seeing gaps in my wooden floor too. my humidity is set to 40% but nest only shows around 31-35%.
Have you wires your Humidifier to run the furnace whenever it needs to? can it run the furnace without heat call?
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Supahhh wrote: Have you wires your Humidifier to run the furnace whenever it needs to? can it run the furnace without heat call?
that is a good question. how can I check that ? it came to my mind that does humidifier can make the furnace run when it detects low humidity level ? I am using nest thermostat btw.
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brampton90 wrote: that is a good question. how can I check that ? it came to my mind that does humidifier can make the furnace run when it detects low humidity level ? I am using nest thermostat btw.
well just raise the humidistat to a higher level and the thermostat to a couple of degrees lower and wait to see if the fan start running?
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Supahhh wrote: well just raise the humidistat to a higher level and the thermostat to a couple of degrees lower and wait to see if the fan start running?
Great thanks. I will try that this evening and update here.

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