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At the risk of being torn apart by hair trigger tempers, I have an observation about tight houses. Of the twenty or so kids I grew up with in my very rural area, about a third had asthma. Can you guess which ones of us grew up in drafty (or is that draughty) old farmhouses and which ones grew up in new, tight houses with forced air systems? Not a very scientific approach to the question, but my Dad once pointed out the corellation to me. He also pointed out to me that most of my sick friends’ parents were not smokers, but they had asthma anyway. The only connection he ever figured out was that they lived in overly tight houses. (He ALSO pointed out that when he was a kid, he didn’t know anybody with asthma, or anybody who had asthma-like symptoms. Seems like a fairly new developement.) As I said, not very scientific, but interesting, anyway. Fire away. I have thick skin.
Now for my question. My husband and I are wrangling the forced air/radiant heat issue. I’m new at all this so I was wondering which might be better. We plan on living in our rafters…no attic. His brother is the HVAC sub, and he says radiant is too expensive, but I hate the way forced air heating makes things so dry and I can’t stand air conditioning. We spend so much time outside in the summer, anyway. The lot is very shady, the greatroom floor will be tile and we have thermal mass on our side. (Finally found the deciding study on that one…made up our mind to go log. Couldn’t put the decision off any longer. Plus, their mortagage company had a DIYer package. Call me a sellout!) I know there have been some heated technical debates on this topic. I just want to know what to consider when making the decision. We’re heating about 1400 sq. ft. and we’ve already picked out a nice catalytic Vermont Castings wood stove in place of the traditional inefficient (and expensive to build) fireplace. It will be our backup heat and I’ll probably cook on it from time to time. Thanks in advance for the input!
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.........Greenmother....you have your observation, but I don't get your point ?
if you mean we should live in drafty houses, maybe we should...but with oil spiking at 2$2.30 a gallon here, I don't think that's viable......
If you want to discuss heating, you should take this thread to Heating and post it...the focus will be a little sharper over there.........
Mike Smith
*Correct me if I am wrong, but it seems like you are confusing the discussion of attic ventilation with indoor air quality. Attic vents, or lack there of, have nothing to do with the air seal of the rest of the interior of the house. One can easily argue for a tight house with a ventilated attic. The thread to which I think you refer has little to do with either attic ventilation or tight houses. It has something to do with water in jars and the venting of spleen.
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My apologies. I thought I read a post by Mr. DuHamel in the Lagano thread about tight buildings making people sick . I guess it must have been in another thread. I apologize for being irrelavant. I withdraw the question. Is there any way I can delete this thread, or can I have Andy do it? Andy, get rid of this thing, please. BTW, of course I don't advocate drafty houses, but breathing wall tech has been utilized in Europe (including the cold parts) for a long time and using it in the US wouldn't kill us.
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GM
Don't go away so quickly.. .didn't you say you had a thick skin???
Who care what friggin thread it's in, or for that matter what bloody folder or sub folder. .. although it is too bad you just didn't add your thoughts to one of the three(?) ***ventilating*** cross threads that are currently running.
The Asthma thing is a decent observation, although with a young son with symptoms, and living in a decidedly drafty, but seriously dusty house, I must add that my research suggests that Asthma is now considered a world wide epidemic in children and is thought to have more a of global environmental cause than just
i local
environment.
We had a really positive impact on my sons problem when we packed in the woodstoves, and installed forced air heating. Our house is dusty because of years of wood heat predating our purchase, my woodworking shop in the basement and my wife having also done pottery in the basement for several years before I fixed her up with an outbuiding to do it in.
Now we
i do
clean, and we have gotten rid of several dust creating elements ...but short of steam cleaning the place, we'll probably never get rid of the dust that just keeps circulating with the forced air. . . but my sons symptoms are almost completely gone!! The fly ash from the woodstove was the single biggest culprit, along with clay dust and dog/cat dander. . .we had it all!!! And no we don't smoke!
I don't share all your observations re: forced air heat, but if you have the option, radiant seems kinds nifty.. .Just ask Jeffie McGough, he'll design you a system, and Jack-by-the-stream will put it in for ya. . .just don't let let Blue near yor site with his backhoe.. . he uses it for framing!!!
An observation about the Catalytic Combuster...Vermont Castings make a nice stove, but they may be the only woodstove manufacturer left who use Catalytics.. .the technology has evolved and they are considered dinosaurs. They are also problematic, and absurdely expensive to replace.
-pm
*Hello Greenmother!I did indeed post that info, exactly where you thought I did. (Joe's Experiment with the jars)I mainly posted the info because it brings up some interesting thoughts about the way the industry is moving in regards to venting. For many, many years in my region, experts were telling us that complete exchange of interior air on a frequent basis was necessary in order to keep the air clean, and the occupants from getting sick. Suddenly, in the eighties and nineties they started to change, and decided that tight houses were the way to go as far as energy conservation, reduction of damaging levels of condensation, and comfort of the occupant.Now, according to the HVAC national convention, they are going back to the thinking of air exchange for safety. Comfort and condensation levels are now secondary to health considerations.I was most curious what the participants here at BT thought about all of this, and whether or not they thought, like I, that maybe, just maybe, the liability factors of an airtight house were causing a concern in the building industry. Maybe this is why they are deciding to go back to massive air exchange. It does have a tendencly to keep airborne particles at a minimum, which lets the builders, hvac companies, and everyone else involved in the construction of a house off the hook for liability in case of a "sick house"Unfortunately, either no one cared about the info, or they didn't realize what was being discussed. Most probably passed it over without even reading it.Oh well...James DuHamel
*James, slightly off-topic, but darn near everyone in my cube city has space heaters running all day--but just because air re-circulates has not done a thing from keeping most of us from catching each others' colds, sequentially. I think they also made buildings w/out windows that open to keep the liability down from potential suicides :/ Myself, I'd rather see bars on office windows than windows that don't open. Of course, I'm outvoted.
*James - I haven't seen too many people here advocate bad indoor air quality or not providing sufficient air exchange for health reasons. But thats is separate from uncontroled holes in the building envelope and separate still from venting the attic. Sometimes I'm not sure what you are referring to when you se the word venting.
*What most here are talking about when they mention venting is the attic area. Vent/no vent attics - that's the ongoing argument.However, MOST still advocate AIR TIGHT living spaces, and argue over venting or not venting the attic. I am refering to the AIR TIGHT living spaces. To simplify what is being discussed by the professional associations and medical experts, let's take a look at your car's a/c controls. You have two settings for the air circulation. You can set it for recirculation - this means that you are recirculating the interior air of the car. This is cold air that is being recirculated, and it keeps the occupants a little cooler. It is easier to keep cool air cool than it is to cool warm air. Unfortunately, with this setting, you are recirculating stale, old air. The second setting is for the introduction of outside air over and through the evaporator core. This allows fresh air into the vehicle, but it takes longer to cool, and the passenger is not quite as comfortable. Keep in mind this introduction of outside, fresh air. In an automobile, the Federal gov't long ago regulated the introduction of outside, fresh air. No matter what you do, there is still some outside fresh air being introduced into the car's interior. It is automatic, and you cannot stop it. They made this mandate because of the number of people that were being poisoned by fumes, vapors, etc... that were finding their way into the car's interior, with no fresh air in the passenger compartment. It was too much for the occupants to handle. Fresh air introduced into the passenger compartment on a regular basis has helped keep the passenger compartment air fresh, clean, and safe.Now apply that to those air tight living areas of houses. No outside fresh air circulation is involved (at least not to a scale that these professional and gov't agencies consider to be necessary for healthy air) These agencies and professional organizations are now concluding that fresh, outside air should be recirculated throughout the house (not on a MAJOR scale) on a regular basis, and have greatly increased their idea of how much complete air exchange should be going on in order to maintain a HEALTHY house. They have used, as examples, houses that have air infiltration problems around doors, windows, seams, etc... and considered them to be safer than air tight houses. They even discuss the introduction of some type of fresh air via a vent, outside fan, or some other source. They are not sure exactly how this fresh air should be introduced, moved around, and then expelled, but they are deciding that it needs to be done. As I said before, they believe comfort of the occupant and costs of heating/cooling become secondary to safety of the occupants. Now to me this doesn't mean that we should just open doors or windows, or cut holes everywhere to let fresh air in. That's kinda silly. What it does mean, is that somehow they think we need to be introducing MORE fresh air, recirculating it around the house, and the expelling it and bringing in more. They are discussing techniques that will be best for the introduction of fresh air, without totally scrapping energy efficiency. It's gonna get interesting.Can you imagine, in let's say 2 years, if all of these guidelines and rules become the standard practice of building and remodeling? Those that are advocating air tight houses will either have to change their methods and beliefs, or be left out to fend for themselves. The industry experts will be saying "fresh air and lots of it" while those still advocating air tight will be labeled "idiots", "con artists", and so forth. The argument can be that they are not up with the industry standards, or that they are going to make you sick if you use them to build or repair your home. How will we deal with this? Will it even be a problem that we NEED to worry about? This is all just food for thought, and not saying this IS how it will be, or even how it SHOULD be. This is just saying... What if?I always liked the exchange of ideas and the debates on BT because they cause us to think, and to open our minds to possibilities and ideas that we may not have thought about otherwise. Unfortunately, part of what I keep finding is closed minds, and arguments for why someone is right, and the other guy is dead wrong. What I keep seeing in these discussions about venting is two distinct groups that advocate their way of doing things. One group is pro venting, the other is against it. These two groups each contain some pretty intelligent people, and they each have their own ideas and thoughts about the why's and whens of venting. I look at both groups and wonder how can either be totally wrong if this many professional people believe so strongly about their ideas and techniques. I have concluded that venting is necessary and good in some situations and climates, while air tight attics are good in other situations and neither is totally wrong, just a different way of doing things. Just my humble look at things....James DuHamel
*James,I don't think airitight envelope construction is at odds with a constant supply of fresh air.In fact I think the two can dovetail nicely. There are two reasons for thightening the envelope. One is to conserve heat. The other is to prevent damaging moisture from building up where it isn't wanted. I would think that it would be better to have a sealed envelope in connection with some kind of whole-house HRV than an uncontolled envelope. That way you know how much air is really being supplied, and you can control where it enters and exits from.StevePS: maybe the HVAC guys are just looking for a new way to sell more stuff, like expensive whole-house HRV systems
*I am finishing up a home that is made from ICFs and is considered to be very "tight". The ICFs go the whole way to the second floor and the roof ties into the IFCs (even the gable ends are poured). Anyway, to the point - we decided to put in a "whole house" air-to-air heat exchanger for the reasons discussed in this thread. We vent the house from 6 places into the central unit that is in the attic (the attic space and eves are in the conditioned envelope). The central unit expels the collected air and brings in fresh air. The fresh air is then introduced into the cold air return; which is then mixed and circulated through the house in the forced air system. We plan on running the HVAC system on constant fan mode to promote movement of the air in the structure at all times. (There are many other variations we considered - I can describe more later if you want)Just another note - I have found and read that a lot of people WITH breathing problems (allergies, etc...) prefer tight houses - and that the drafty houses usually mean that more particulates (dust) are moving around, and that outside particles and such can be brought into the structure and moved around more easily... Three people that I talked to before I built actually built tight houses due to there allergy and asthma problems – and have been thankful ever since.You have to remember that even in a tight house you have fresh air - every time you open the doors to leave or enter - and if this happens 10 or 20 times in a day - you have a good deal of new air.The attic ventilation DOES relate to the whole issue - it is the overall movement of air that is important - the big picture.
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FYI Breaktimers, I re-named this thread at the request of the original poster.
Andy Engel
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.........when designing comfort systems (HVAC) ASHRAE sets up certain standards to design to,,,,
my references may be out of date.. but generally the minimum for residential fresh air replacement is 5 CFM per person, with most spaces being designed for minimum of 5 people, recommended level is 7-10 cfm / person so for an average house we would be looking at 25 - 50 cfm fresh air any way you can get it....mostly this is dependent on odor...health, dust, etc. don't have as high a requirement..
...some of the studies I've been reading in the popular press link higher incidence of asthma to a reduction of capacity in the immune systems...remember Granma telling you you had to eat a peck of dirt before you die...
she didn't mean we were supposed to over- medicate with antibiotics...
bottom line...fresh air is one of the major design considerations in any good house....VENT or NO-VENT...
*Lots of info on asthma if you do a general search on the WEB. From one of the (About.com?) sites on asthma:The colds, flu, and other infectious diseases endured during childhood may fulfill a function just now coming to light. In the past year a number of studies have discovered that these infections may serve as a training ground for children's developing immune systems. The decreased size of families, improved hygiene, and decreased incidence of infection may have contributed to the worldwide increased incidence of asthma. There is also research which strongly indicates that children who have various parasites do not get asthma. Unfortunately, I don't know what parasite you should get for your kids to prevent it...One other reason that a "tight" house may result in an increase of asthma is that the waste of dust mites are thought to be a trigger of asthma and dust mites can't thrive in cold and drafty places. Giving them a nice warm bedroom with enhanced humidity in a modern house is just what they need. Fastidious cleaning to get rid of dust mites has been found to help asthma sufferers.
*..indoor air quality..here's the parametersthe humidity of the airthe temperature of the airthe cleanliness of the airthe odors in the airhumidity is best controlled by limiting the source and then adjusting the level with humidification or dehumidificationtemperature is your choice of heating / cooling equip., but you simplify the job by super insulatingcleanliness generally has two components: pollutants from outgassing and combutions productsand the second component is dust....dust can be externally generated (in the air outside the house, pollen, soil, etc)or internally generated...people 1st and pets , 2d, unless you've got a lot of petspolutants is best controlled by source mitigation and dust is best controlled by filtration , change your vacumn to hepa filter type, and use external discharge central vac..clean the air with a media filter, hepa styleodor is usually a function of people and cooking and the only practical cure is fresh air..... change the air
*I'm surprised nobody has mentioned the i .33 air changes per hour (which equals 1 full air change every 3 hours, or 8 full air changes per 24 hours)that has been a basic requirement in commercial construction for over 25 years. .. at least here in Canada.When the super-insulated residential R2000 programme (basically a super-insulated poly bag masquerading as a house) brought on the new era of i tighthouses 20 years ago, ventilation air was required to be provided by mechanical Air Exchangers. None of this is new. All new house construction is now required to have mechanical air supply, either HRV's or A-AHX's.Mechanical air supply is not without it's own problems. Many so calledi sick buildingshave been found to have inadequate mechanical air supply due to bad design, faulty installations, or in the most absurd examples, intake air vents that were installed in parking garages where they constantly sucked in Carbon Monoxide!! On a personal note, I've always had misgivings about the reliance upon these mechanical systems, and would rather "engineer" in some natural drafts to help create a i failsafe system, especially where combustion air is required for fuel burning appliances.-pm
*James - If the 2 year thing happened as you described it I think we'd have an oil crisis like the early 70's. But more to the point of my previous post, it seems you still equate tight construction with no air exchange - and I don't read anyone here advocating that. I believe that variable and controllable air exchange would make much more sense - allowing it when and where needed. Besides, "air tight" is pretty casually tossed around with very little quantitative measurement.
*There's also quite a bit of info re asthma and stress as a (primary) causative factor. Just picturing, not to mention living in, a "tight house" might be additionally stressful. FWIW.
*Patrick:Care to expand on what a A-AHX is? Havn't herd of that one and couldn't find anything on the web.Thanks
*MattSorry, I usually don't throw around very many acronyms. . . i Air to Air Heat ExchangerBox with two fans running constantly which draws in outside air through a heat exchanger that is simultaneously exhausting inside air. . . whole outfit connected to a forced air heating system. .. looks like R2D2 on a respirator, heart monitor and intra-venous.-pm
*Fred,"I look at both groups and wonder how can either be totally wrong if this many professional people believe so strongly that the Earth is flat."I didn't say that, you did. And if you believe this to be true, more power to you. I personally don't believe this because it has been proven wrong with substantiated, documented FACTS. "Im one of those people who takes exception to your position and theres no polite way to put it. The by guess and by golly years are over. You, me, the government, and everybody else agrees that indoor space needs proper ventilation. Just do it."Again, this is one of your quotes. What exactly is my position? Since I have not stated it, are you now reading my mind? Is that another of your valuable talents? Areyou saying that I believe in venting, and I am an idiot for doing so? I personally believe that venting is good in some cases, and bad in others. Each home being built, and the area in which it is built will dictate when, if, and how much venting should be done. Some will need it, some won't. The problem is that the so called "experts" can't agree on what exactly "PROPER VENTILATION" is. They differ on their ideas about how much ventilation is necessary, and how tight is "too tight". To me, you seem so stuck on one idea that you can't see the forrest because the trees get in the way.The whole idea behind my post was to find out what everyone's take on the HVAC convention summary was, and if it was something that we should seriously be taking into account in our ever changing industry. Remeber when they sided houses with asbestos shingles? At the time, they thought this stuff was better than ice cream, and would last a lifetime. NOW, through years of research, testing, and seeing the end results of long term exposure to asbestos, builders, remodelers, and homeowners alike have determined that asbestos shingle siding is dangerous if disturbed. Will builders and remodelers look back 10, 15, or 20 years from now and wonder how the so called experts of today could have been so stupid as to think air tight houses were safe, good, and the best way to build? Do not assume that this is a stance by me on ventilation of a home. I have already stated my opinion and belief on the matter. This is all a "what if" type of question. The only thing I have ever seen you actually do (from reading MANY, MANY of your posts both here and in the archives) is chastise someone who thinks differently than you, or believes in different ideas than you. Because of this, I do not take much of what you say seriously anymore. If you want to maintain your crediblity with me (I can't speak for others) then you need to present facts and documentation to back up your ideas. Without facts and documentation, your ideas are only theories. Theories make for good reading, but they are still only theories. Saying that you have seen, or you have done only proves experience, not expertise.Now you may very well be an expert in this type of building and repairing where you live, but your ideas and methods don't hold much credibility where I live. This is two completely different climates and conditions. I do not deal with snow, ice dams, basements, or oil fired boilers for heat. I have shared your thoughts and ideas with local experts, and they all have pretty much agreed that it may be a better way where you are at, but a lot of your methods and ideas aren't the best thing to do here. (The roofing experts here got a good laugh out of your leaving the felt paper on for so long of a period of time)Just my humble opinion...James DuHamel
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At the risk of being torn apart by hair trigger tempers, I have an observation about tight houses. Of the twenty or so kids I grew up with in my very rural area, about a third had asthma. Can you guess which ones of us grew up in drafty (or is that draughty) old farmhouses and which ones grew up in new, tight houses with forced air systems? Not a very scientific approach to the question, but my Dad once pointed out the corellation to me. He also pointed out to me that most of my sick friends' parents were not smokers, but they had asthma anyway. The only connection he ever figured out was that they lived in overly tight houses. (He ALSO pointed out that when he was a kid, he didn't know anybody with asthma, or anybody who had asthma-like symptoms. Seems like a fairly new developement.) As I said, not very scientific, but interesting, anyway. Fire away. I have thick skin.
Now for my question. My husband and I are wrangling the forced air/radiant heat issue. I'm new at all this so I was wondering which might be better. We plan on living in our rafters...no attic. His brother is the HVAC sub, and he says radiant is too expensive, but I hate the way forced air heating makes things so dry and I can't stand air conditioning. We spend so much time outside in the summer, anyway. The lot is very shady, the greatroom floor will be tile and we have thermal mass on our side. (Finally found the deciding study on that one...made up our mind to go log. Couldn't put the decision off any longer. Plus, their mortagage company had a DIYer package. Call me a sellout!) I know there have been some heated technical debates on this topic. I just want to know what to consider when making the decision. We're heating about 1400 sq. ft. and we've already picked out a nice catalytic Vermont Castings wood stove in place of the traditional inefficient (and expensive to build) fireplace. It will be our backup heat and I'll probably cook on it from time to time. Thanks in advance for the input!