My house is in northern Wisconsin and is built on 2×4 walls with 1/2″ OSB sheathing, no house wrap, viscuine plastic barrier over inside of insulation, and 1/2 inch foam board backed on both sides placed on the inside over the viscuine barrier with 1/2 in drywall. Vinyl siding. Windows are Kolbe and Kolbe thermopane and the ceiling has got approximately 12 inches of blown in insulation. It is a raised ranch with a walkout lower level. the lower level has a concrete floor with carpeting on it.
The humidity in the winter months in the lower level stays approximately 50 to 55%. the main level humidity stays between 57% and 67%. I have to run a dehumidifier to get it down to lower levels. If I leave it at the high levels condensation builds up about 6 inches on the windows overnight on the main level and about half as much on the lower level and doesn’t totally disappear during the day leaving the window sills constantly wet. If I wipe them in the morning (which I usally do) it builds up again during the day but not to the extreme that it does during the night. I keep the temperature at approximately 70 degrees during the day (the lower level stays about 67) and at night I lower the temp to 64.
How do I get the humidity down to normal levels which I believe to be between 45% and 30% depending on the outside temperature without constantly running a dehumidifier. Incidentally, I do not have a humidifier, so I can’t accidentally be putting humidity in the air do to a faulty humidifier.
If anybody can help please email me at [email protected].
thanks,
Lad
Replies
Oh, that's easy. To reduce the amount of humidity you are adding to your house, simply
Do not cook; bathe; have a shower; use water of any kind; breathe; or allow another living being to do the same.
To deal with the humidity already present , always keep a window open.
Install a Heat Recovery Ventilator to get rid of the moist air in the house and bring in dry cold air. May have to preheat outside air to prevent freeze up. Get a good AC contractor.
Just a few questions.............
Does your clothes dryer vent to the outside? If "yes" check for blockage.
Are you heating or using a "ventless" fireplace or heater?
Do the bathroom or kitchen vent fans exit to the outside of the house?
If you use gas for heat or hot water, check to see that the stacks are clear?
Is the basement "dry" or does it seep moisture?
Are there a large number of house plants?
Are there any large aquariums?
Do you have a hot tub or steam room?
Have you checked for "leaks"...roof, sidewall, plumbing?
A little detective work may lead us to an answer....................Iron Helix
One more question? Are the diffusers (registers) directed towards exterior walls and windows as to "bathe" these surfaces with warm, dry air? Also, do we have window coverings installed (blinds, curtains,etc) that create a sealed air space at the window, thus inhibiting air movement????....
Thanks for all the questions, I didn't realize that I had to go to the postings to see any responses to my concerns. I thought that I would get email. I am glad that you sent me the email to ask me to go to the postings.
Our cloths dryer vents to the outside and is clear.
No ventless fireplaces or heaters.
Bathroom and kitchen vents go to outside and seem to be working properly.
exhaust comes out of stacks for furnace and hot water heater which are propane gas. So I assume they are exhausting properly.
Basement is dry except in summer when hot air mixes with cold floor and condensation causes concrete to become damp at times.
No house plant, no aquarium, no hot tubs or steam rooms.
No roof, sidewall or plumbing leaks that I am aware of. IE: no stains on ceiling or walls. I did have a leak in front entrance door that rotted the floor but I replaced the door and floor several weeks ago and the humidity has not dropped.
Diffusers point along follr away from exterior walls.
We do have blinds on several windows and I have noticed that if we colse them at night the condensation is slightly worse but leaving them open its still bad.
Someone else recommended having our combustion appliances checke by a heating contractor trained in Building Performance Institute Protocol Carbon Monoxide analysis.
Do you know if there is someone out there with somekind of a device that can measure change in humidity by going along your walls or ceilings etc to determine if there is a specific place in the house that is generating the problem?
I appreciate your response. Thanks for the questions and I hope you may have some other ideas.
There is one other thing that I can tell you and that is that the house does not have any drain tiles around the foundation, but many houses up here where the soil is rather sandy don't have them. And seeing as the humidity in the winter is higher upstairs then in the lower level I kind of discounted that as the culprit.
Thanks again,
Lad1001
Well, my questions didn't produce a culprit, but eliminated some possibilities.
Please describe the flue/vent construction for the furnace and water heater. I am assuming that it is a forced air system! PLease include furnace BTU rating, vent sizing, flue size and total height to the vent cap.
Sometimes improperly applied vinyl siding saturates exterior sheathing.....do know the details on the siding application?
Are there any crawlspaces attached to the basement, or does the basement footprint match the first floor footprint?
Take a flat backed rubber mat or a small piece of plastic weighted with a small throw rug and place it on the basement floor adjacent to the wall opposite the walkout side. Leave overnight............next morning pick up and look to see if moisture has left its mark in the covered area .
.....................Iron Helix
The furnace is propane forced air. 74000 BTU. It is a 92% efficient with 2" PVC for the intake and exhaust which are vented 2' above roof. The entire run of the intake and exhaust go up 3' from furnace then angle about 3' then go straight up approx 10' through main floor ceiling then go close to horizontal about 4' then straignt up approx 2' through trusses and then the 2' above roof that I mentioned earlier. Looking at the installation instructions for the furnace it seems to be within the limits of the run max length for the size PVC that it is. I am not a heating contractor so I am not an expert at this.
The hot water heater is propane with a 3" galvenized exhaust pipe. It goes up 3' then angles about 6 1/2 feet across room then straight up about 11 feet to roof and extends about 3' above roof.
The main level extends about 1 1/2 feet over the foundation for the length of the house (about 42'). the rest of the house fits the footprint of the basement.
No crawl spaces.
I have looked under the vinyl siding when I had to replace the front door because of the piece of rim joist that I had to replace. I had to disasemble part of the front deck which required removing some siding. It was dry. I have also felt the bottom of the sheathing under all the perimeter of the house where the siding ends. The only place I have a problem with wet sheathing is in one corner of the back of the house where the walkout is. The soil was up against the house allowing moisture to infiltrate behind the siding. I am not sure how far up the sheathing is affected in that area but I believe it is not more than a 2 square foot area. I corrected the problem with the soil but have to wait till next spring to pull the siding off and replace a section of the sheathing. I don't believe that little area could be causing my moisture problem.
Have not yet tryed putting down a plastic or rubber backed rug yet.
Today I bought a digital CO dectector that allows you to check the max PPM over a period of time. I am trying it in different parts of the house for a period of time to see if there is any CO showing up. It supposedly will show down to 11PPM.
This is really frustrating. I thank you for taking an ongoing interest in trying to help me resolve this problem.
Lad1001
Frustratiung, indeed. Please keep us posted.
PS, what brand of CO detector? I'm not familiar one with that lowest level.
Its a Kiddie CO dectector which detects CO and gas. It only registers 30 + PPM on the screen under normal operation. If you push the peak level button it will show you the max ppm since you last cleared the highest value. When you check for the peak it will show you anything 11 or over that has occurred (thats what the directions say).
Lad1001
This detective story is sadly lacking in clues that will lead us to the guilty party!!
The forced air furnace usually creates overly dry air for a residence......my only question about your 90+ efficiency furnace is concerning the use of a proper drain for the condensate removal from the vent stack...check it out.
A relative humidity above 20-30% in the winter is usually high enough to cause "window sweating"...so your 50% is way out of range. Someplace in your house there is some place or thing that is pumping a lot of water into the interior. we need to find it!!!!
I ask again......are the bath fans/kitchen fans REALLY vented to the outside....and not just to the attic?
Please do the "plastic mat" check on your basement floor....it will help determine if there is a water problem.
Again....How long has this been going on? Maybe more history will help? Has this house always been this way?
Just .....GRABBING AT STRAWS.....................................Iron Helix
My furnace has a drain connection to the floor drain. The humidity does fall about 2 or 3% on average when the furnace is on but when it shuts down the humidity goes back up. We have had some 15 degree nights and in the morning the humidity is around 53 to 57 percent. Even if no one showers or runs the dishwasher it still goes back up. As far as the bath fans go there is a vent above each bathroom that I assume is for the fan vent. They would serve no other purpose. BUT, I have not gone on the roof while they are running to see if any air is coming out of them nor have I craweled up into the attic space to see if any vent pipe runs up to the roof vents! I do have one in the lower level bath that does vent right into the joist space above the drop ceiling. I didn't know this when I bought the house. But that bathroom is rarely used and when it is we close the door and open a window for a short time to vent it. I have to vent it outside next spring.
This has been going on probably as long as I have owned the place (5 years). I have not lived here fulltime until 3 months ago. So I really never checked the humidity. Whenever we were here we would just wipe the windows off in the morning. When we were gone the temperature was set down to 55. I never found the time to check it out. It might be worse now then it was in the beginning, I really can't recall if it was as bad in the past.
Incidentaly, the house was only 2 years old when I acquired it.
This house must be pretty well sealed because the heat doesn't go on very often. We don't get much wind where we are either because we are pretty well protected by the thick forest around us. Without the wind the turnaround of outside and inside air is minimized.
I got to try the plastic mat thing. Maybe tonight!
I just had an interesting thought not related to my problem. In the winter when the snow covers the bathroom exhaust vent and the ridge vent on the roof how does air excape from the fan vents and how does air circulate through the roof between the ridge vent and the soffit vents? I have thought about this before but came to no conclusion.
Lad1001
Time to visit theattic.
The sequence on the vent fans and the roof vents is often a culprit. The roofers cut in the vents as designated bt the general contractor early in the construction sequence when going to a dry shell condition. The Electrician at a later date installs the vent fans. Then the insulation is stuffed in and the drywall is installed...etc....etc.
What I see when asked to inspect an attic is the vent fan exhaust tube has not been installed....bcause the lectrician says it is not his job, and so says the insulator and drywaller.....................so if the GC is not paying attention to this detail, it slides under the rug.'
Also in cold climates a long piece of uninsulated vent duct from the fan unit to the roof vent may allow for the moistire to condense in the duct and drip back into the house insulation.....another item on the attic checklist.
I have even seen where the fan vent cap was installed in the roofing, but the roofer did not cut the hole out of the plywood!!
The other condition you will want to inspect in the atticfor wil be signs of water damage on the roof sheathing from the extreme humidity in your house migrating from the living area into the attic and then condensing or freezing on the much colder roof sheathing. When the sun warms the roof the frozen humidity melts and saturates the plywood. Often turning the surface black with rot and mold.
I do hope this is not what you find!
If snow covers the vents on the roof----they will not release any air by convection. But a fan forced bath vent with warm air and moisture should force the melt back of the snow to allow venting....unless there is a deeeep snow load.
On a 15 degree morning, with a bath vent fan on, a trip outside to view the corresponding roof vent should reveal wisps of condensing vapor....take a look.
Keep digging....there has to be a reason.....................Iron Helix
Well, we are eliminating things. I went up in the attic today and the fans are connected to the vents with insulated duct. The distance is negligeble anyway. I went on the roof and had my wife turn on the fans and felt warm air venting from them. While looking in the attic I checked all around for moisture marks. It looks like the day it was built. No signs of dark areas or sagging insulation. I could see most of the roof area, although not every little crevus. I have to assume the rest is in good shape also since there are no suspicious areas anywhere else.
I put plastic down last night under a rug and this morning it was fine, no moisture.
Maybe its my wife's hot flashes that are causing the problem!
I hate running the dehumidifier all night, but it does help even though its a small one.
If I don't find the culprit this winter I will have to pull some of the vinyl siding in various places in the spring to make sure the sheathing is dry everywhere. I don't know what else I can do.
Speaking of construction where its nobodys job, I remember a lump under a carpet in a house that turned out to be a empty package of cigarettes that the carpet installers left because it wasn't there job to clean the floor before laying the carpet.
lad1001
My,My,My...................we're stumped!!!!!!!!!!!!
Does anyone else have any considerations??????
More IMHO's are needed.
............Iron Helix
I'm starting to think we need to call in what's his name, Mr. Spock, and "Unsolved Mysteries!"
That floor drain in the basement sounded like a possible clue to me. S'pose the house is drawing a steady damp airflow out of the floor drain somehow. Where does the drain go? In a 2 year old house I would expect the basement slab to be sitting on a layer of crushed stone, which would make a pretty decent humidifier if you could pull some air through it.
Just a thought,
Pete
The house is supposedly 5 years new.........so a floor drain left open to the aggregate fill would be a major plumbing/code error. I would doubt it ............but, stranger things have happened.
Could rent an optic fiber "snoop" and thread it into the floor drain.
If it the floor drain was open then there would need to be a mechanical reason for a strong vacuum to draw an air flow from that defective drain. The owner's "rubber mat test showed no moisture capture........therfore the floor is not weeping humidity into the house's envelope.
It would be nice to be able to do a "walk thru" on this problem.......somewhere there is an unseen problem that is keeping this house far too humid for it's own good!
Keep Looking...................................Iron Helix
I would have thought the natural "chimney" effect of a warm house in winter would provide plenty of draw.
I agree that the drain shouldn't be able to draw air from under the slab. I thought of the drain though becauseI just ran into the landscaper who did my house a few years ago, and he mentioned that they buried the outlet of the footing drain while installing the lawn. I had just assumed that it went out to a nearby storm drain. Just goes to show not everything goes according to plan!
The mystery continues...
Pete
The drain needs to either run to daylight or a storm drain, or a pump.
Just burrying it it will not do any good unless it is buried a long distance from the house in a dry well and you have good drainage condtions.
I had a different problem with buried drian. I live on a hillside have a "stepped" house. The lower level had air ducts under the slab.
The drain from the upper level footings has been buried. Now the normal slop of the ground allowed most moisture in the ground to drain off.
But about every 2 years we have several days of rain followed by a heavy rain and the ducts would get flooded about 1/3 of the way. BTW when the furnace kicked on that made for a "GOOD" humidifier.
Rerouted the drain and have not had any problems since.
It wasn't buried on purpose! I'm told the GC chewed the lanscaping crew out big-time. He didn't go back and find it though.
Pete
One potential source of excessive humidity is flue gases not being venting properly from the house, and flue gases can contain dangerous amounts of carbon monoxide.
Have your combustion appliances checked immediately, preferably by a heating contractor (or home inspector) trained to do Buiding Performance Institute Protocol Carbon Monoxide Analysis.
Get and use a good CO detector: one with a digital readout, or a low level monitor such as at http://www.aeromedix.com
Look at the top of your water heater under the "bonnet" at the bottom of the flue, is there a lot of dust or debris? If so, feel around the bonnet when it's fired up, if you feel heat, get it checked ASAP
Visually examine the furnace and water heater flues (and dryer vent) to make sure everything is connected.
Don't screw around with combustion gases, cause they'll screw around with you!
Thanks for the input.
I have checked the bonnet on the hot water per your suggestion and it seems OK. I have a CO detector but it doesn't have a digital readout only a beeper if the CO get above a certain level. As for the combustion inspection maybe I should have that done although this problem has been going on for 5 years. I just havn't tried to solve it because I wasn't living in it full time until a few months ago. I would think if the CO was the problem we would have been feeling light headed or headache symptoms sometime in the last 5 years during the times we spent here.
It is very possible to have CO problems without knowing it. Although high levels can kill, exposure to unnoticable low levels can cause serios long term health problems.
Just because you aren't dead (and don't have headaches) doesn't mean you don't have a CO problem.
Get a good CO detector; the one without the digital readout isn't sensitive enough.
Here are a couple of bandaids that might help.
First for the front door, Put on a storm door if you don't have one. it will take the brunt of the wind pressure that drives the water under the door and wets your flooring & framing. Have had that problem with my place in Kewaunee and the storms helped dramatically. Even with the refrigerator seal provided on the Stanley entry steel doors the water blows thru at the bottom 2 inches at the jamb.
Second, do you have gutters / eaves trough on the building? If not then hook them up and route the water away from the foundation. Wet blocks/ poured walls provide unseen moisture thru the wall in your walkout area. It gets sucked into the Cold air intake and then heated and condensed in the upper windows.
Third, consider painting the basement walls. A PVA sealer and a top coat of paint will give you a barrier. It won't be as good as one of the real sealer types but it will diminish the transfer of moisture to the building by a dramatic amount. Did that with my home and it also cuts the dust in the lower level.
Finally someone above suggested that you make sure you have a freshair inlet to your furnace for the heated air (not just the combustion side). The air inlet goes in the air intake of the Cold air return. That will keep air from sucking in the cracks of your home. It also gives you some make up air for the appliances that aren't sealed combustion. That would include a fireplace that I don't remember being referenced. Firewood (stored) is a tremendous source of moisture as well as the burning of firewood.
Keep writing. Great detective story.
PS. If you look around the windows tell us if it has the tar/foil sealer that seals between the OSB & the window nailing flange. I have a neighbor that didn't have that on his home built in the last decade. He gets mini drifts of snow from under the window casings in heavy winter blows. Speculative construction and tract buildings tend to ignore this seal cause it is $10.00 a window and is never noticed when people are buying a new home unless it is viewed before the siding goes on. The Kolbe windows (unless the thermopane is steamed inside) are a good product, it is an installer problem.
I'd bet the window flange (tar foil) seal is missing. It isn't required by code as far as I know but it is a good practice.There are solutions if this is missing. Solutions aren't as good as the "strip siding, seal, & replace" option but it can be done.
No, the house does not have storm doors. The entry door is a Taylor (supposed to be good, cost enough). I have thought of a storm door but had hoped I wouldn't need to put one on. I know I should.
No I do not have gutters only eaves that overhang about 1 1/2 feet. The heavy snow is tough on gutters up here although probably 50% if the homes have them and I havn't heard anybody complain of problems.
When you say that the moisture from the foundation gets sucked into the cold air intake are you speaking of the furnace combustion intake. If so it is on the roof where I wouldn't think it would be affected by moisture on the foundation.
the house is a raised ranch so the whole back side is 2x4 stud wall and the other 3 walls are foundation only 4' up. They have a viscuine barrier on the foundation wall with studs and insulation and drywall over them. So painting is not an option without ripping everything out. I should say that at least the utility room is that way. I know because I had to take the drywall off the outside wall in that room for reasons that I won't go into here; therefore I assume he did the rest of the finishing down there the same way.
I don't understand what you mean about the fresh air inlet to the furnace through the cold air returns? I have combustion air drawn in from the PVC on the roof and have cold air returns to the furnace, I don't understand what else there could be.
I have a fireplace, have not used it yet this year.
I believe you are correct about the tar foil. To the best of my recolection the vinyl siding J-channel has nothing behind it but OSB board at least on the sides of the windows, I don't know if Kolbe windows nail in with a flange like Anderson windows. I don't remember seeing one behind the J-channel, unless it doesn't stick out as far as the J-channel.
At least Kolbe windows have a decent warranty. I had two picture windows that lost there seal because they collapsed inside and a condensation spot started to form in the center of the window pane. Kolbe sent me new windows but I had to replace them.
Thanks for the suggestions.
Lad1001
Is the fireplace of masonry construction? This could be our culprit!
Your statement about "J-chanel directly to the osb" at the windows sends chills down my spine.......major rot may await you if this is so!
Still chasing the elusive condensate demon!
.................Iron Helix
No its not masonry. It ls of the heatilator type, a metal insert with thin brick facing in the fire box and a circulating fan to pump room air behind the box and out the top of the box back into the room. I never use that feature of it, it seems useless with a fan that barely moves air.
I do believe that the J-channel is nailed directly to the osb. I will have to pull some siding and look. I may be thinking of when I replace the door. there the J-channel is nailed to the osb along side the brickmold of the door.
Lad1001
So is the chimney made of triple wall all fuel chimney? or is it a masonry ? How is the chimney/roof flashing done?
I'm looking for any possible source for a water leak...........Iron Helix
ps....a wood moisture meter would tell you if certain areas of drywall within the house are "wetter" than others, but would leave telltale pinholes where the probes were pushed into the drywall. Might not be noticed behind drapes/curtains or at moilding lines.
"ps....a wood moisture meter would tell you if certain areas of drywall within the house are "wetter" than others, but would leave telltale pinholes where the probes were pushed into the drywall. Might not be noticed behind drapes/curtains or at moilding lines."
There are non-pin moisture meters available, until it'd be a lot of $ for 1 job. Try looking the http://www.inspectortools.com site
Bob,
Thanks for the reference to inspector tools..........a addition to the list......
.................Iron Helix
I was out of town for a while. Noticed lots of messages about the subject.
The chimney is metal pipe all the way out the roof. I don't know if it is triple wall. All I know is that it goes straight up then bends into a closed off area in the garage where it goes up through the garage roof. It looks to be flashed OK on the roof.
There is just one drain in the basement utility room and it goes to the septic field (I assume).
My son who is in the buisness of carpet cleaning and water damage restoration says that the moisture meters are not what they are advertised to be. They leave a lot to be desired.
I don't remember if I had stated that the house does not have drain tiles because of the sandy soil in the area. I thought this might be a problem but the plastic mat test seemed to eliminate any moisture problem from the basement floor.
I also don't think I had ever indicated that I have a May-Aire fresh air recovery system. I assume that the original owner put it in because the house is sealed up so good. I have been running it every time the furnace goes on and the humidity has been staying between 45% and 50%. The outside temperatures have been averaging between 15 and 35 degrees. I wonder if the humidity will go down if I keep running the May-Aire when the outside temperature fall further as the winter progresses. The furnace does not run very often, so I have to assume that the air exchange is pretty slow. I would think that running the May-Aire system should have lowered the humidity way more than it did if I didn't have some kind of a moisture problem.
I am not familiar with the May-Aire unit................but let me make a suggestion.
Disconnect the May-Aire for a while and see what happens to the humidity in the house. ............................Just for the irrational joy if it!
If nothing else seems to point to a solution then by all means install the largest available portable dehumidifiier and set it to reduce the humididty to less than 30% or untill your windows quit sweating.
The constant wetting of the interior of the window sash will effect the finish and eventually cause the rotting of the lower sash rail. The expense of such a replacement set-up for all your windows will be costly. Not to mention the wasted time and drudgery of daily window wipe-down.
...................Iron Helix
After the last note, I took some time to wander about the web for "May-Aire" air sytems. Did not find an exact match.
A general knowledge resouce for you to check out is: http://www.extension.umn.edu/distribution/housingandclothing/DK7284.html
What came to mind were more questions?!!
Is there a humidifier installed on the forced air furnace? Normally a forced air furnace creates a deficiency in household humidity levels in the heating season and is usually equiped with a humidfier.
Is there a humidifier included in the May-Aire unit? If this unt contains a humidifier also, along with the furnace then we are being "double dosed" on humidity.
What are the specifications as to the acual function of the May-Aire? There are heat exchangers, energy recovery units, air exchangers .....all combined in assorted sequences to make units for your house to address the quality of the indoor air. It would help to know the exact function of this "May-Aire".
As another after thought concerning our discussions and your potential lack of a siding "underlayer".....go to the local homecenter and buy a siding tool used to "unzip" pieces of siding from the house. This will allow you to release the bottom edge of a piece od siding for its full lenght and the lift same so see what is really underneath your siding......and then "snap" that piece back into position after inspection....removing no nails. By doing so you can acyually determine how youy siding was applied and look for water damage without "RIPPING" it all off.
This lackof resolution, as you can see, BUGS me.......................Iron Helix
"Normally a forced air furnace creates a deficiency in household humidity levels in the heating season and is usually equiped with a humidfier."
A nit pick here; as I understand it furnaces heat cold dry air that infiltarates a house as the warmer air escapes; the furnace doen't actually dry the air.
Also, in my area (NW Ohio) newer, tighter houses have less or no need to add mositure and humidifiers are common, but not "standard."
________________________________________________
"I may have said the same thing before... But my explanation, I am sure, will always be different." Oscar Wilde
'Nit Picking" allowed...............the same semantics result in low wintertime interior humidity. Even drier than a dessert humidity reading. Thanks.
Yes, tightly built houses pose a different problem.............stagnant air, water vapor accummulation.
Our local economy usually spends only as little as possible for a house. Air Tight equals more money......so it usually doesn"t happen. Often outbid by a "DOUBLE WIDE". In about twenty years the locals will catch up with today.
At least the pace is slow and easy........................Iron Helix
My money is on the The May-Aire unit - an air-to-air heat exchanger. Is it installed properly? Did the installer know what they were doing to get it set up for proper operation? Do we think it EVER worked correctly? If it's working right, this puppy should be doing a good job at removing the excess humidity in the house
Some things to check:
Are there dampers on the system that are not open?
Are both the inlet and outlet fans working?
Are the fans working to full capacity? There should be a rheostat on it to adjust the fan speed.
Is the condensate drain plugged?
Are the filters clean?
Is the exchanger core plugged? It's removable for cleaning.
Is the auto-defrost cycle working? When the inlet air temp lowers to 34°F the inlet fan should shut down until the outlet air raises the inlet temp back to 55° again, then the inlet fan starts up again and the cycle repeats itself. If this doesn't happen, the condensate in the unit will ice the core and plug it up.
If everything is working as it should, can you set the unit to run continuously instead of just when the furnace cycles?
Here is the manufacturer's info - you can contact them for help, too
Snappy Air Distribution Products
1011 11th Avenue SEDetroit Lakes, MN 56501USAtel: 218-847-9258 fax: 218-847-6322
Thank you for the info on Snappy. I did however have the operation instructions for the may-aire which had Snappys phone #. I did call them for a chat. They were helpfull in explaining just what you said about what happens during a freeze up. They said that if there is a damper on the input for the outside air that I should close it slightly during really cold weather to help keep it from going into defrost mode. I see no place where there is a damper on the incomming duct. Most of the duct is within walls where I can't get to it and the duct in the attic where the vent to the outside originates is all insulated. So I have no way of cutting down on the inflow of air. The filters are clean, both fans operate, but the thermostat control is not turned all the way up. I did play with the adjustment on it but I didn't notice any difference in sound of the fans to indicate that they increased in speed. I suppose I should turn it up all the way and see if it makes a difference. Maybe I just can't tell that the fans are going faster. The green light stays on when operating so I assume all is well. The red light has never came on when I have looked at it so I assume it has not frozen up yet. I don't think it has been cold enough yet for the incoming air to 34 degrees. It travels quite a ways from the outside to the May-aire unit and probably warms to above 34 before it reaches the May-aire. The core is probably OK because I have not used the unit until recently. The original owner of the house never said anything to me about it. I didn't even know what it was supposed to do until recently when I read the directions and talked to Snappy! It seems like a waste to me to insulate a house extremely well and then have to use something like a May-Aire to draw fresh air in to cut down humidity. It uses energy to operate and draws in cold air which cuts the efficiency of your furnace so it has to run more and use more gas. Whats the purpose? Its like a vicious circle.
One other thing I failed to mention - I think you said in one of your posts that the May-Aire was only running when the furnace cycled. Can you set it up for continuous operation or control it with a humidistat instead of running only with the furnace?
Keep in mind that with a well sealed up house, you not only need that to get rid of humidity, but also to create an exchange of the stale. stagnant air for fresh outside air. The difference between this and a leaky house, of course, is that this is warming the incoming air somewhat instead of sucking in ambient temperature outside air.
BTW, where in northern WI are you? I lived in Mountain for a while - just north of the Menominee rez - before I moved to the Milwaukee area. My Dad is in Suamico, just north of Green Bay.
Edited 11/18/2002 7:39:13 PM ET by allaround
The May-Aire is independently controlled. I have to switch it on. I want to get it set up so that it goes on automatically when the furnace goes on but with an override so that I can turn it off if I want to. I don't want it running continually. If the humidity does not stay low enough with it running with the furnace only then I will have to rethink the issue. I do like the idea of a humidistat setup that you mentioned. I will have to look into that.
I will probably feel stupid after you answer this one, but what is BTW? I am a little south of Minocqua.
BTW=By the way ;>) Aahh, Minocqua - used to fish and vacation in that area in my younger days. Back in the '50's some of those lakes were so inaccessable they were only fished a couple times a year. Had a friend who ran a restaurant kind of on the border between Minocqua and Woodruff. Closed it up after the touristas were gone in the Fall and came back down by Madison to work as a tilesetter 'til it was time to go back to 'God's country' in the Spring.
It really sounds like you've exhausted trying to find any unwelcome sources of water and come up empty. If the house is really tight and well insulated it's just going to accumulate moisture from your daily activities and not give it up - hence the need for the May-Aire. The other thing to consider is that if the house is good at holding the heat in, the furnace isn't going to run much so coupling the operation of the May-Aire with the furnace isn't going to do much good - it just won't run enough to get good complete air exchanges.
As a check, turn it on and let it run continuously to see if the humidity level drops. If it does, you've found the solution to your problem and you can begin to cut back on its frequency of use until you reach the point where humidity becomes a problem again. I do think the best control, in the event this solves the problem, is to use a humidistat. Any way you cut it, this is going to be less expensive than running a dehumidifier.
Go outside to the inlet/outlet area and make sure it's really sucking air in and blowing air out - it's supposed to exchange about 240 cfm so it should be obvious if it's really moving air both ways. Make sure the air exchange is taking place inside the house as well - with the furnace off and the May-Aire operating, you should be sucking air into the cold air registers and blowing it out the warm air registers.
Did the installer separate the inlet and outlet enough so it's not just sucking the exhaust air right back into the house?
Yes the intake and exhaust are far apart from each other. The intake did have a hornets nest established by it cutting off a slight amount of the opening, but not much. Fortunately hornets dissapear in the winter, so I was able to knock the nest down and get rid of it. I am glad I looked at the input or next spring the hornets would have been back making the nest bigger. You don't want to mess with hornets on your own. I had another one up here in the summer that was under a step on my deck. I had to have a pro come in and get rid of it. There were hundreds of hornet in that one. Anyway the air flow seems significant and the humidity drops about 5 percent or so when the furnace is on. Of course it goes back up when it is off. If I run the May-Aire when the furnace is not on you cant feel any air flow out the heat registers so I have to run the furnace blower motor to circulate the air brought in by the May-Aire. I am sure that by doing that the humidity will fall even further. I just have not done that yet because the humidity has been low enough to keep the windows from sweating during these days of the teens at night and 30 or so during the day.
I have been coming up to the Minocqua area for many years to fish and vacation with the wife and kids. Wanted to live up here for a long time. Now I am here and fished only twice over the summer because I have been so busy with getting the house in order. Hopefully that will be different next year!
The May-Aire is a Heat Recovery Ventilator system. It takes the outside air, somehow uses drawn in house stale air to warm the outside air slightly and sends the outside air into the cold air return to be mixed with inside air. The stale air that it used to warm the outside air is then exhausted to the outside. It does not have a humidifier and neither does the furnace. The humidity goes back up to around 55% to 58% when the May-Aire is not operating. With the May Air operating the windows barely sweat. I hope that with the colder weather the humidity will drop further due to more heating cycles with the May-Aire operating. Hopefully this will keep the sweating in check. Again, I still think this level of humidity is too high for the current outdoor temperatures.
I have used the zip tool to take apart the vinyl siding when I replaced the front door unit. I had to pull siding for a distance to get my front deck apart and replace a section of rim joist. All of the OSB that I saw during that process looked fine. I have not attempted to examine any other sections due to the cold weather. I am afraid I would break the vinyl seeing as it is probably very brittle in this cold air. I will do that in the spring.
My wife put a good coat of varnish on the bottom part of the windows where the condensation settles last year before we moved into the house. That has helped to keep them from rotting. They are in good shape I am happy to say. I am going to have a furnace repair man come out and wire my May-Aire so that it goes on with the furnace blower. That way I won't have to remember to turn it on every time the furnace goes on. I looked at the furnace wiring diagram but was confused as to how to hook up the may-aire to it. Usually I can figure those things out, but not this one.
Hi Lad.
Been reading all the posts with interest. Iron Helix has done an outstanding job in trying to cover all the possible water sources that can infiltrate a house. Surprisingly, every answer you have given him has turned up zilch.
Here's a thought. Perhaps your house envelope is tighter than a drum! It's not drawing moisture in...its simply not letting moisture out.
If your furnace is firing properly, (which you say it is) and no moisture can be detected from the basement floor ( the mat test) and your clothes dryer is venting properly, (which you say it is) as is your bathroom vent fans,( again, you report they are OK), then I would suggest that you simply try opening (crack open slightly) 2 windows for a cross ventilation effect. Your humidity will start to lower. BTW...this is the cheapest and the easiest answer given you to date. Will it work effectively? I honestly don't know, but a lil fresh air ( especially cold winter air with lower humidity) will definately not hurt. If this does the trick, then you can thank me later.
Just for the record, my clothes dryer is not properly vented ( been meaning to fix it for a long, long time now), nor is my upstairs bathroom fan, which only vents into the attic. My basement floor actually does wick up ground moisture, and I have a masonry chimney that is located on an outside wall that causes it too to wick in moisture. Yet with all these "large" water sources entering my house, I have to TURN ON A HUMIDIFIER; because my humidity is so low. Why? it's an old (1930s), drafty house. It's not "super drafty," but there is enough ventilation to keep the moisture from building up inside.
New homes today are too air tight...which albeit is your problem. Open the windows.
Davo
Yes, Iron Helix has done a great job of covering all possibilities. I wish one of them would have uncovered something. Of course there are a couple of things I have to check out in the spring.
I don't know if you missed reading the posts about my May-Aire system. It basically does what opening the windows would do, it brings in outside air and mixes it with inside air through the cold air return and the furnace distributes it during its heating cycle.
My last house in Illinois had the second level bath fans vented to the attic. The first level baths were set up to vent above the ceiling between the joists. When I saw that I was furious and had the installers vent them to the outside wall of the house. Fortunately I saw this when venting them was still possible. I don't remember if I didn't notice that the second floor fans were vented into the attic or if I just didn't bother having them vent them out the roof. We didn't use the second floor fans much because of the venting to the attic, instead we opened the window in the bathroom for a while after showering.
I had indicated in one of my posts that my lower level bath fan does vent directly into the ceiling between the joists. I don't use it now. In the spring I am going to vent it out the side wall. Fortunately it has a drop ceiling and the run to the outside wall is short and unobstructed so that it will be pretty easy to do (I hope!).
I sure hope that my humidity problem is mainly due to the house being sealed up tight rather than some underlying problem. I still think that there is more to it than just a well sealed house though.
Gotta get a storm door. I tried that for 2 years and it comes down to the bottom 3 inches of each jamb that leak. It'll never be air tight even with the highest tech seal. Pressure differential outside to inside drives the draining water from the surface of the door thru the gap. As my wife said "get over it".
Gutters drain the water away from the building and into your neighbors window wells. I think it would help and certainly keep the sump working less.
"the fresh air inlet to the furnace through the cold air returns? "
This is new tech. (5 yrs or so) When new high efficiency furnaces are installed in a tightly sealed home the windows always steam up due to body moisture, the shower, cooking, etc. If you use exhaust fans the make up air has to come from someplace doesn't it? The solution is a damper and an inlet. the inlet hooks to the Cold Air Return to the furnace. When the furnace is on the dry outside air is sucked into the CAR and heated. To a lesser extent the bathroom fans and kitchen fan also pull in the air. Some are cheap some take waste heat from the furnace (exhaust) and temper the incoming air (expensive)
"J-channel has nothing behind it but OSB board "
That is where 70% of the moisture is coming from in my opinion. Get out the caulking gun and see if that works. If not consider prying all that stuff up in the spring and sealing it better.
In overview. Storm, fresh air inlet, and caulk. You are going to be busy. The gutter is longer term but put it on the 5 year plan.
Booch, do your stanley doors have the bottom seal pads installed at the connection between the jamb and threshold? If not, contact stanley and request a couple and put them on. This should keep out water and air at that location. There are different thicknesses available (at least the hinge side pad). __________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Yep, bottom seal pads are there. sort of like Mohair 1 x 3 inch blocks. Normal locations would be served fine by this. My place is on the shore of Lake Michigan 40 foot above the water with a western exposure on the main door and SE exposure on the other. 50 to 60 MPH winds are not unusual. Generally only in storms but the pressure is incredible. Realize the other side of the building has negative pressure, so the differential at the door jamb is substantial.
I've caulked with 50 year stuff every step of construction, I even wet the casing joints on the exterior. Great stuff fills the gaps between the shims, etc, etc. The whole building has ~ 150 tubes in it at every joint that had potential to leak. It is definitely the door. It took 2 beers one afternoon, but I saw the path.
Thanks though, I didn't know those pads had a name.
Not sure I've seen the mohair pads on the stanley's around here. These are two different kinds, one a tapered vinyl cloth covered spongy pad, the other more of a close cell foam pad bout 3/8's thick. The wedge shaped one goes on the latch side, the straight pad on the hinge side. Email me your address, I'll drop a pair in the mail. Even if the storm door blocks the rain, I would think air would still come in. Worth a try to tighten it up b/4 winter.__________________________________________
Remodeling Contractor just outside the Glass City.
http://www.quittintime.com/
Question did they put plastic between the sheet rock on the ceiling and the joist in the attic or over the insulation and staple it down. If they did it you are living in a big plastic bag, the humidity has no place to go.
I don't know if there is plastic between the sheet rock and the ceiling joists but I do know that there isn't any above the insulation in the attic. I suppose I could dig down under the blown in insulation to see if I get to sheet rock or a plastic barrier first. I thought that it was good to put plastic between the sheet rock and the ceiling joists although neither of my previous houses had it.