humidity in the house?

just out of curiousity.....this was our first winter in this home and we noticed that from about end of Nov to almost Feb, that the humidity in our home displayed itself as tell-tale condensation on the lower edge of windows. (northern ontario canada climate)

That was about 60% humidity...and we still have it. Its not uncomfortable, in fact its quite nice in here (no static, dry lips, etc). but the moisture I don't like in the winter. We tried running a borrowed dehumidifier, and it did NOTHING. Pulled all of 3 drops from the air overnight.

At 60% humidity would the dehumidifier not be working overtime???? What are my other options to controlling the humidity? I've got a new bathroom fan installed and shower with the bathroom window open (all year). Older furnace, no other accessories other than central air (which obviously controls the issue in the summer). What could be going on? Is it that the dehumidifier I borrowed didn't work??

any ideas on a more permanent solution? I know an air/air exchanger will work wonders, but the cost is prohibitive. I heard that running a "fresh air intake" to the intake side of the furnace works well....any ideas? just cut a hole in the wall and run a duct to the intake???

I'm stumped!

b
Reply to
Hamilton Audio
Loading thread data ...
60% humidity sounds wrong, what kind of humidistat do you have . Was it calibrated, Taylor sells them up to 25% out of calibration, Menards, Ace all had the same junk. I had to find a large display analog and calibrate it. 60% rh at 10f or less and your exterior walls would be literaly wet and your windows would have puddles under them. A little condensation as you describe happens, but depending on window type may not be a concern. Do you have dual pane argon, what brand . What temp do you keep the house in, farenheit. Dehumidifiers can frost some as high as 67f and not work. What are winter temp ranges in, farenheit. First you need a good humidistat.
Reply to
m Ransley

Does your humidistat read anything other than 60%, ever.

Reply to
m Ransley

"Hamilton Audio" wrote in news:aL9vc.645105$Ig.9283@pd7tw2no:

The only way you can have 60% humidity in winter is with some very heavy humidification.

You have condensation on your windows because your windows are bad and so the insides of the windows are very cold, and this is acting like a dehumidifier and sucking out the last few drops of moisture. A dehumidifier on top of that? That's funny.

Reply to
Chuckles

I wondered....

regulated inside temp all winter = about 70 deg average outside temp during winter = about 0 deg or less

Yes, the humidistat did move up and down some, but still stays at 60% right now!! The dehumidifier I had did not frost up. I agree....I'm going to have to get a good humidistat!!

The windows in the house are all wood framed, double pane glass from 1984. Brand is unknown but the glass is labelled as Twinsulite II. The windows were essentially sweating somewhat, no moisture on the walls :) I don't like the idea of water streaking down the window frame, sitting there deteriorating paint/drywall and perhaps getting in behind...

any ideas on how to lower??

b

Reply to
Hamilton Audio

You need fresh air , a recircuator , or a way to introduce fresh air, but im no hvac pro. Do you have a condensing furnace , one that uses outside air for combustion , or a real tight house , with tyvek. Without a good humidistat you cant say how far you need to go. But yes condensaton should not happen.

Reply to
m Ransley

Just in case, make sure the furnace is venting properly -- ie, make sure the chimney draws correctly and is not partly blocked. This can create a high moisture situation in a closed-up home (water is a by-product of combustion), not to mention a dangerous carbon monoxide hazard. It's probably not your problem, but worth a check.

Reply to
Tom Miller

"Hamilton Audio" wrote in news:h3bvc.645415$Ig.349541@pd7tw2no:

To repeat, you don't have a humidity problem (or your dehumidifier would have collected water). You have a window problem. Your windows have gone "soft", i.e. the space between the two panes is no longer air-tight. 20 years is just about the average lifetime of double-pane windows made in those days. I am sorry to be the bearer of bad news, I know replacing windows is more expensive than running a dehumidifier.

Reply to
Chuckles

I think not. A very tight house or a damp basement will do it.

Not necessarily.

Sounds natural, on a cold day.

Might be a good idea in wintertime. About 60% more efficient than electric resistance heat, as a latent heat pump...

Nick

Page 2 of

formatting link
mentions that a 1981 Canadian housing development holds the world record for low air leakage...

Page 5 says the voluntary Canadian IDEAS standard calls for less than

0.15 m^3/h of air leakage per square meter of house envelope with a 50 pascal blower door test, which is equivalent to about 0.15/20 = 0.0075 m^3/h or 0.0127 cfm/m^2 or 4 cfm of natural air leakage for a 2400 ft^2 two-story house :-)
Reply to
nicksanspam

I agree that it's very hard to believe a std older home as the OP described would have 60% humidity with outside temps of 0 during the winter with forced air heat. Some small amount of condensation around windows is normal. I'd check the windows, as leaking drafts, etc will cause condensation. Further proof is that the dehumidifier didn't remove much water.

BTW, if you think a heat exchanger is too expensive, how expensive do you think it would be to implement the idea of just hooking an outside air intake up to the return air duct? The operating energy wasted will be huge.

Like just about everyone else, I have the opposite problem and have a humidifier installed on my forced air furnace. And it does a great job.

Reply to
Chet Hayes

I'm thinking of adding evaporative cooling to my home, and none of my local stores seem to know much about it regarding a non-standard installation. So, I thought I'd ask here and see if anyone can spot potential problems I've missed.

The reason I want to install an Evap cooler is to reduce my electric bill because using my present AC can cost up to $200 a month. I'd also like to be able to use the cooler on "fan only" as an alternative to opening windows when the weather isn't too hot.

First, my install plan; My home has a combined forced-air heater/AC (gas heater). I was planning to use the existing ductwork for the evap cooler.

My heater/AC is in a utility room on the lowest floor of my home, and ten feet from a wall that divides the living area from a dirt and rock floored crawlspace (the air in there is cool and dry; no moisture in the crawlspace at all.). The crawlspace has twelve-foot ceilings in that area, and I plan on installing the evap cooler in the crawlspace. (outside mounting is not an option; it would cause too long a run of ductwork to get to an outside wall. Roof mounting is also much too far, and in any case forbidden by my homeowner's association.

Basically, I plan on running the cooler air into the main forced-air junction box that's on top of my heater/ac. An alternate plan would be to run the cooler output air into an AC return duct that passes right over where I want to put the cooler. That would be far easier, but it's only a 14" round duct and it does not look large enough. Aside from easy installation, that configuration would also run the cooler output air through my air filters, which I would like. In either case, I plan on installing some sort of flapper valve that will close automatically when the cooler is not in use (so when I'm using my AC or heater I won't be losing air back through the evap cooler).

My main concern is that the utility room is vented, via a duct, into the crawlspace, for ventilation of the water heater and heater/AC. My concern is that the cooler will create low relative air pressure is the crawlspace, and thus a reverse flow in the water heater "chimney", which is a four inch vertical pipe over three stories tall.

If this is the case, could I just attach an airtight duct to the duct between the crawlspace and the utility room, and extend it thro9ugh the crawlspace to outside?

Also, there are not enough air entry points into the crawlspace for the airflow, so I was going to put a screened cutout in the crawlspace door (which is on an outside wall).

Plumbing won't be a problem, nor will electrical power. I have a dedicated 15 amp line in the crawlspace that is used only for one

9-volt fluorescent light. There is a drain line below where I want to mount the cooler, and also a cold water line nearby, so I do not anticipate pluming problems. (I plan on putting a drain valve in the cooler pan, for flushing and seasonal draining.)

I'll be going to city hall to see about permit and code requirements in a few days, provided this plan still looks feasible. There are no city or state codes here, just national ones.

A few more details; the climate here (mountains of Northern Arizona, altitude 7000') is usually dry, but in July, August, and September can be very humid. Daytime temps in the hot months (May through October) often run in the 90's.

The house is a little over 4000 square feet, well insulated and sealed against air leakage.

Anyone see any problems in my plan? Also, how do I figure out what size evap cooler to get? My present AC unit (Trane XL-80) is undersized for the square footage of the house, but due to the house having good insulation and being built into the side of a mountain it works just fine winter and summer.

Thanks in advance.

Chris

Reply to
Chris J...

as I understand it, when the "seal" blows, you get condensation BETWEEN the panes of glass. I had this condition on a single pane downstairs. My condensation is on the INSIDE of the unit, not between the panes. I know that the windows are due for a change, but I'm in no hurry.... :) :)

b
Reply to
Hamilton Audio

I'm guessing this is a very tight house....definitely NO moisture issues in the basement, we use it as living space everyday.

Again, agreed.

formatting link

goes to show you that not all older homes are bad :) actually its interesting. this house is approx 1300 sq. feet (for a total of 2600 sq feet of heated living space). I have the IDENTICAL furnace as I did in the previous home of 800 sq feet (total of 1600). My heating bills are LOWER here :) Same town, same gas company, same weather. Larger house, less bills = less leakage.

b
Reply to
Hamilton Audio

You asked..

You got UpDucts for this too right??

Nope.. Not a good idea. Do what you want, but the ductowrk for the AC isnt sized correctly for an evap...period.

Then you need to give it up, and purchase a higher SEER AC unit..

Read what I said about AC ductwork not being large enough.

No. Thats called in the trade, just damn stupid.

It is also very illegal.

And your idea violates the International Mechanical Code...the standard code.

Plenty.

The evap cooler company can tell you...or, you can just go to Home Depot and buy the biggest one you can find.....LOL

Then its not undersized is it? There are NO Rules of Thumb for SF/Tonnage. If your unit is working, (altho, I have doubts about how well, since I never broke $200 in good old Palm Springs, nor did my father in law in Phoneix and he had over 3500SF of home....) then its not undersized.

Reply to
CBhVAC:)

My main concern would have to be running all that water laden air over your heat exchanger in the furnace. A furnace is not designed to handle that level of moisture. If you have a lot of condensation on the heat exchanger you could shorten the life of your furnace.

Reply to
Paul James

And I am looking for criticisms, thanks. I'd rather find out here than after I rip holes in walls whether this idea will work or not.

No, I don't. I was planning on replacing some attic access hatches with screens during the summer months (would that count as an actual upduct?) . The attics are all ridge and soffit vented. I was thinking that air flow through the attic would also help cool the house.

The ductwork in this house is almost all rectangular box, several of them leading out from the junction on top of the heater/AC, and I've seen that used for Evap. Of course, I have no idea if this is adequate or not. If not, then my Evap cooler is a non-starter.

That's an option... I'll have to phone Trane and see if they have a SEER rating for my present system (XL 80, about ten years old) as I can't find one anywhere on or in it, nor on the web (everything on the web I've found is for newer XL 80's). (this unit was present when I bought the house, so I wasn't involved with the installation). If I can get significantly higher SEER, I'll do it if it isn't too expensive.

If that's the case (not doubting you, but my ductwork capacity looks larger than in similar houses I've seen) then that sinks my idea. Thanks for tipping me off to this potential problem.

I didn't mean attach to the water heater "chimney", but rather to the duct that vents the utility room into the crawlspace, basically just extending it a little. Or is that what you thought I meant, and it's a bad idea (and illegal)?

Which part? Putting an Evap in a crawlspace, or the ductwork issues, or both?

About the only place in town that sells them, other than installation companies, is the home depot, and they were the ones who wanted to base it solely on square footage. (I live in a fairly small town).

I've been told it is, but I disagree as it works fine, or seems to. It does not run anywhere near continuously (more like 10-15 minutes an hour in severe heat or cold) unless I've just turned it on and it has to make a major change in interior temperature.

I managed to break $200 in Phoenix in a small apartment on more than one occasion, but I suspect that was a cheap AC unit.

One problem with this house is the design; it's sort of staggered up a mountainside, so it has a disproportionatly large surface area. It also has a large cubic area due to having twenty foot ceilings in some areas. It also has a heck of a lot of windows and walls with full western exposure.

$200 was for a month with record heat. $70 to $110 is more common (but that's just the increase caused by the AC, not the total electric bill).

Thanks for your comments and help.

Reply to
Chris J...

Uhoh, that's another factor that did not occur to me, thanks. I'd have to put some sort of anti-backflow flap between heater/AC and the ductwork junction.

Reply to
Chris J...

Sigh.,....

It wont make any difference at all to the life of the unit, unless of course, you have a 40 year old design.... Been down this discussion before...

Reply to
CBhVAC:)

NP...installed, and ripped out and RE installed more units than I care to remember...I have a pic on the office wall on my last evap install...on a rooftop in CA, and everytime someone asks me about one here, I tend to look at it and go....No.....way..... Altho..most people dont understand why I dont like working on the duct design n this are for them...since they are about as easy as anything...

It would, but an UpDuct is a barometric duct. You dont have to worry about heat from the attic, putting a cover back in place, etc....you just put one in each room that you want cooled, or two, depending on the size and area, and the amount of airflow you have from your ducts from the cooler, and when the cooler comes on, badda bing, you have no windows to open, no doors to worry with, and a cooler home.

And the #1 design of western AC ducts...(Drumroll please.........) is what you describe. Now, granted, Ihave said it before, and will say it again, *I* cant see it from here, but I can promise you one thing....AC ducting, is NOT adequate 99% of the time for a swamp cooler.....particularly a MasterCool2 unit.

10 year old XL80 would be a max if 10SEER, the lowest rating there is currently. ARI has jumped the min standard from 10, to 13 starting Jan 1st,
  1. In your area, a 14 SEER would actually be a big jump now, and in a year and a half, it will be the equal to todays 12 SEER.

Ok..heres something to think about...6 inch duct....100CFM...roughly. Depending on the tonnage of your current AC, you prob have either 8 or 6 inch take offs going to each run to the room. Unless you have about 20 of them, 6 inch would be too small to properly get enough airflow to each room, and be able to benefit from the cooler.,...unless you are installing a tiny unit....and even then, its a possibility that they are too small for that. Most installs even with the smallest MasterCool unit or similar, used a min of 8 inch duct, and most were 10, some even as large as 12...evaps need, and demand airflow. in, and OUT of the home.

No..I know what you mean, and what you propose would create a negative pressure zone, OR, the possibility of it. You cant do that. Your water heater is going to fire up at some point when the coolers running, and all that exhaust, will be pulled into the home.....granted, it SHOULD be heading right out the open spaces to the outside...but its still not a good idea, ever, to introduce exhaust gassses to the living enviroment...its also very illegal.

The crawlspace idea, while novel, might run into a couple of issues....its going to depend there on your inspections department. The ductwork...Umm...doubt anyone there in the department has a clue about that....its the gas water heater issues that I can see that kill the idea from the word go.

Let me explain one thing to you...HD employees are drones....total, complete, idiots for the most part. Go to the website for the brand of unit you are looking at, Adobe and other brands all have a sizing chart that is fairly simple to understand.

The ONLY way to know, is to have a manual J load calc done....to insure its proper. Too large of a unit will short cycle, and cost you more to run......

Or sized wrong..:) See it all the time.

No problem, but keep in mind, that you have other alternatives still yet to consider. Just curious...how much attic space do you have?

Reply to
CBhVAC:)

If I had any sense, I'd probably shy away from doing this project myself... :-)

Could I fit those into the attic access hatches? The hatches are just sheet drywall, but I could replace that with wood or steel and paint it.

More like 40 of them...

The reason I thought mine might be adequate was that the configuration is different from most I've seen (I'm a realtor so I see a lot).

On top of the Trane unit is what I call the "main junction" (Sorry, I don't know the correct terminology for any of this). It's basically a square box, and out of it come three "main ducts", which are approx

12"X24" (giving me an outgoing ductwork cross section total of about six square feet). one of these "main ducts" has five wall registers directly into it and also a few standard floor registers on six-inch pipes. The other two have smaller standard floor size registers, off of 6" pipes. There are a total of about five large wall registers, 25 floor registers on 6" pipes, and a dozen more even smaller registers (such as under-cabinet, bathroom, etc.) on 4" pipes.

When the blower on the Trane is running full power, the air (hot or cold) comes out of registers more like a draft. But, one nice thing is it's totally silent.

If you still think this is insufficient ducting, I'll scrap the project, but I just wanted to be sure I'd described it adequately. Other AC installations I've seen have just one or two of the 12X24 or similar sized ducts coming out of the main junction. I've never seen four before.

Thanks.. you just saved me a major job, if I do end up being able to put in the cooler.

Also, if there is some flow through the AC unit and back out the three AC return registers, that effectively adds to my ductwork capacity.

Does increasing the SEER by 40% roughly reduce electrical usage by

40%, or am I misunderstanding the ratio here?

Due to the age of this system, I'd be willing to spend a few grand for a new, high-SEER one to save 40%, but I wouldn't to, say, save 10%.

I've got at least that, plus several larger registers that are installed directly into the box ducts.

Why wouldn't a larger number of smaller ducts equal a few larger ducts in capacity?

How? The utility room would be isolated from the crawlspace by what I propose. The Utility room would be vented to the exterior instead. (by running an airtight duct through the crawlspace to an exterior wall), so how would it be different from venting the utility room elsewhere? Other then the present vent duct from the utility room to the crawlspace, there is air connection between them (they are not even adjacent). I'm not trying to refute what you say, I'm just making sure I didn't explain myself badly and give you a false picture of what the end result would be.

Agreed that I definitely don't want any chance of exhaust gasses in the house.

Unless I can resolve the ductwork and the water heater issues it's a definite no-go. I'm not worried about the gas furnace part of the Trane, as it's a powered exhaust, and I can't imagine wanting to run the heater and the cooler at the same time anyway.

I know that (:-)), but they also are about the best informed people in this area. (says a lot for the area, huh?).

I'll go to several, thanks!!!!!! (I have no idea on brands yet so I'll check several)

If I understand the term right, I'd need to hire someone with a lot of experience; there are too many unusual factors here (it's kind of a weird house, but I like it.). The construction is non-standard in many areas; multiple roofs of different (and non-conventional) construction, exterior walls of non-conventional construction (and also in some cases non-vertical) several custom made windows of odd design and shape (such as protruding half-pyramids) etc. Walls with alternating brick overlayed by polished granite, and conventional frame construction in diagonal bands (which change in width as they go up, making it worse), etc. No way I know of to figure R-values for much of it.

When I had my AC serviced last year, I asked about calculating the correct size, and the service guy (from a place that does installations) looked around and shook his head, telling me he had no idea how it could be done.

I remember the AC ran just about continuously on hot (over 115) days. That would indicate a wrong size, if I'm understanding correctly?

That's complicated. I've got three main attics, and a couple of smaller but separate attic-type areas. The attics (most of them) are odd because the interior ceiling is peaked, but the exterior roof is peaked at a sharper angle, so it's a weirdly shaped space. Kind of like an inverted V under a taller inverted V. The attics are separated due to the odd design of the house (the house is three stories, staggered up a hillside, so parts of all are ground level but in some areas the stories overlap) Some parts of the house have no attic (wood ceiling, a couple of feet on insulation, then the roof directly attached) but others have attics. Total attic square footage is around

900 sq. ft, with an average height of (guessing) two feet, but going from a few inches near the Soffits vents to a few feet under the ridge vents. All are accessible.

Are you thinking of putting the Evap cooler inside an attic? There is space, and I did think of that, but I didn't think it would work. The attic interior is warmer, and also the utility room is in a part of the lowest floor that would have a three story vertical with a few zig-zags, then a twenty foot horizontal run of duct to get from the cooler to the main ductwork junction in the utility room. Not only is it a long way, but installing the duct would be a truly massive project, far, far more than I'd ever want to attempt.

Thanks again! Chris

Reply to
Chris J...

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.