We are finishing a basement. Three of the rooms ( theater, work out and bathroom do NOT have windows to the outside.
On framing insulation inspection we were told we need to install some type of mechanical ventilation system in these three rooms. He faxed a page to our office with this area high lighted.
Inspector can offer no more apparently. Electrician is clueless and one engineer as well thus far.
Can anyone offer some assistance here?
Very grateful.
Eric
Section R303
R303.1 Habitable rooms. All habitable rooms shall be provided with aggregate glazing area of not less than 8 percent of the floor area of such rooms. Natural ventilation shall be through windows, doors, louvers or other approved openings to the outside air.Such openings shall be provided with ready access or shall otherwise be readily controllable by the building occupants. The minimum openable area to the outdoors shall 4 percent of the floor area being ventilated.
Exceptions:
1) The glazed areas need not be openable where the opening is not required by section R310 and an approved mechanical ventilation system is provided capable of producing 0.35 air change per hour in the room or a whole house mechanical ventilator system is installed capable of supplying outdoor ventilation air of 15 cubic feet per minute per occupant computed on the basis of two occupants for the first bedroom and one occupant for each addittional bedroom.
Replies
That sounds like the inspector wants you to install some window wells for light and ventilation.
Any bathroom must have at least mechanical ventilation and a certain number of air changes per hour. You know, the old air wick can just isn't going to get it and matches aren't the answer either.
That sounds like the inspector wants you to install some window wells for light and ventilation.
The rooms in question have no windows currently so you would be right except that the info he gave us indicates the in lieu of windows you need mechanical ventilation.
Just trying to figure out what this mechanical device is.[email protected]
It's Never Too Late To Become What You Might Have Been
The ventilation needed here is typical HVAC type. It's not necessary to be conditioned air but it needs to be fresh air and that normally means outside air pulled into the area with duct work and fan arrangement of some sort. Typically this is accomplished by simply extending the whole house duct work to include the new basement areas.
I haven't reviewed the code here but as I recollect, the glazing requirement is to allow light in but this can be done with ordinary lighting.The minimums are: In basements there must be at least one escape route that leads directly to an open yard or alley. Exit must be operable from the inside without special tools and must meet certain height and width requirements. This usually means at least one escape window well or similar and escape route other than the stairs leading back into the house.All habitable spaces must provide "natural light" from glazed openings that are equal in area to 1/10th the floor area of the room. These can be fixed or operable glazed windows. If operable then these are a convenient method of gaining the required ventilation too. My code says that this must be light from a window not just electrical light. """""""""""" spaces must be provided with "natural ventilation" by operable windows who's area is 1/20 the floor area. This window vent requirement may be may be accomplished with mechanical system connected to the outside that pulls in fresh air. The volume of fresh air must be able to provide two complete room air changes per hour if a window, or five changes per hour if fan powered duct system.. If the space is just one toilet with shower then the ventilation must be capable of five air changes per hour.
If the bathroom has no shower then the air changes can be accomplished with just a standard recirculating fan to remove odor.
Thanks, good information.
I'm a bit out of the loop on this project, it's not one I am working on directly. I'm not sure that the basement will be served by the current HVAC system that services the remainder of the home. I'll will verify that.
I'm slowly being "let" into the office of the company and non verbally "coaxed" into certain situations, while at the same time not being given the reigns to run the horses.
This is one I have come upon and I am just trying to move this along.
The inspector should have inked this on the plans when they were submitted for permitting.
I do not believe there is a copy of the code book in the office. <;~(
So you can see what I have to work with.
Thanks for the good info.
I did go to fantech, they seem to have lots of pertinent information.
Fantech: Heat & Energy Recovery Ventilators[email protected]
It's Never Too Late To Become What You Might Have Been
we did one with a fan to bring in outside fresh air. a better choice would be a hrv, so frigid outside air would not be encountered in the winter.
I googled and I'm starting to catch on............HRV= heat recovery ventilation?
I'm not sure I get bringing cold air into the house with a fan though. At wil the fan may function? Or through a control, ie; timer etc?[email protected]
It's Never Too Late To Become What You Might Have Been
HRV= heat recovery ventilation Yes that would be the way to go. I forget exactly how we satisfied the code before. I think somehow the contractor pulled the fresh air thru the heating duct. It made the building inspector happy.
Seems to me like the quoted code sectons are fairly clear. What don't you understand?
The only thing I can't quite make out is whether the "approved mechanical ventilation system" must exchange outside air or simply exchange air with the rest fo the house. If the latter then a constant-running HVAC fan (or perhaps a fan on an occupant sensor) would probably suffice.
What don't you understand?
The design I suppose. Seems counter intuitive to introduce outside air into a conditioned space.
The term "exchange" is not used in the code as cited. From other info I have gathered, a "system can be a s simple as a fan and duct that introduces outside air into the room at the will of the occupant. Or one that exhausts inside air creating a negative pressure system.
See: "readily controllable by the occupants"
Occupant sensor is a fresh thought though.
Thanks[email protected]
It's Never Too Late To Become What You Might Have Been
You're not familiar with air exchange ventillators?
Half of the harm that is done in this world is due to people who want to feel important. They don't mean to do harm but the harm does not interest them. --T.S. Eliot
No, not at all.
I googled and got some info, but not enough to make me comfortable enough to go cobble one together tomorrow or Monday which just may be the case.
Home Ventilation Options
Mechanical Ventilation in Homes Simple Installation Methods[email protected]
It's Never Too Late To Become What You Might Have Been
In many parts of the country air exchange ventillators are required in new construction. This is to combat the "sick house syndrome" that results from stale, contaminated air in tightly-sealed homes.I would think that any competent HVAC guy would be familiar with the basics, thought he might have to consult someone else to get the Ts dotted and the eyes crossed.
Half of the harm that is done in this world is due to people who want to feel important. They don't mean to do harm but the harm does not interest them. --T.S. Eliot
Thanks for the help.
Eric
[email protected]
It's Never Too Late To Become What You Might Have Been
I would think that any competent HVAC guy would be familiar with the basics
I know nothing of DanH's market. Here, however, you have to do a huge amount of searching to find an HVAC guy who's more than HAC. Ventilation is considered code satisfied if there's an operable window. Little motivation to learn more.
DanH, I followed then-Canadian code for my house using .5 ACH. Since, I'm told that we're over-ventilated but we have incredibly good indoor air. Such that guests not infrequently remark on it. I cobbled a heat exchanger which is upwards of 90% efficient from some old Popular Science plans. Our heating/cooling system is far removed from what you're presumably dealing with, but we experience no reason to reduce our air exchanges.
Recently I toured the first American Lung Assoc. approved houses in Va. They are designed for less than .3 ACH, coupled with low toxicity materials. PAHS Designer/Builder- Bury it!
Tom, what constitutes an American Lung house?
blue"...if you just do what you think is best testing those limits... it's pretty easy to find exactly where the line is...."
From the best of TauntonU.
what constitutes an American Lung house?
I believed I left with the literature explaining that. Unfortunately, I didn't. This open house was advertised expressly as the first "approved" houses in the state. You might think their literature would explain all that. It didn't.
As I spent most of my time with the HVAC guy, and fending off the listing Realtor, I missed the American Lung representative. Far as I know, it's air changes (fewer than I have), huge emphasis on humidity control (primarily monster dehumidifier), and construction with non-toxic materials in a tight house. IIRC, was positively pressurized (as is our house).
Certification isn't of interest to me, but should be to you. What I wanted to learn was what they were doing differently, why I spent so much time pumping the HVAC guy (who I knew in passing from my previous employment). Unfortunately, he wasn't accustomed to talking with someone who had more than a passing knowledge of the subject (me) and wanted to go over the basics in depth. Residential air systems are all but unheard of here.
What I have yet to do is track down the American Lung representative for a chat. Doesn't sound as if I'll learn any more than what I knew when I designed our air system 15 yrs ago, but I'm always eager to learn. My motivation was figuring out how to live comfortably with my allergies in a high-allergen climate.
We packed up and left Virginia once, to land-shop better climates. During that several month trip I finally got my questions answered, that the allergists here didn't have sufficient knowledge about. Since then I've occasionally consulted with chemically sensitive folks about how to deal with the issue. Antihistimines aren't the answer. Clean air is.PAHS Designer/Builder- Bury it!
Here's a link to the ALA "Health House" website: http://www.healthhouse.org/index.asp
Thank you, didn't occur to me. That should be better than trying to track down one individual who may or may not have my answers.
They even have a place to post ones own story.
PAHS Designer/Builder- Bury it!
You're welcome. I understand that there are a couple of ALA health houses being built in the Charlottesville area. If you're interested, the Charlottesville ALA chapter should have more info.
there are a couple of ALA health houses being built in the Charlottesville area
LOL... Yeah, went to the open house a couple of weeks ago. That's why the subject came up. Got good press advertising and good turnout.
Gawdawful ugly places for half a million in a crummy neighborhood on a postage stamp piece of ground. Priced for my age group (boomer) and stairs everytime you turn around. Makes no sense. But what do I know?
Just looked at your profile. Are you my neighbor? If you're the archy developer, disregard the above.
Sent an email to ALA with praise and criticism of their web site. Mostly very good, but some of those points seemed to contradict each other. For instance, #14 says to have .25cfm/sq ft at 50 Pascals (ventilation). Then #234 says un-pressurized, slightly negative is OK. Nowhere does it deal with volume, apparently assumes one standard ceiling height.
Then the questionnaire on your house never even asks about a fresh air system. Apparently they assume nobody has one. Which is pretty close, but no good reason not to bring it up. Clearly skews many of the other points, radon for instance.
All in all, a good site despite my pickiness.PAHS Designer/Builder- Bury it!
Great link. Thanks Jim
blue"...if you just do what you think is best testing those limits... it's pretty easy to find exactly where the line is...."
From the best of TauntonU.
You're welcome.
I think one of the bigger issues here is the AHJ not inking the plans prior to permitting, but finding a deficiency after the fact and then not providing much info on the correct design for a system he would sign off on.
Combined with his being mostly unavailable for consultation.
Me thinks this is one to hand off to someone of good working knowledge of these "systems" to get it done right.[email protected]
It's Never Too Late To Become What You Might Have Been
The Green Building Initiative specifies 7.5 CFM per occupant so that code standard is double their standard. But we get 7.5 cfm per occupant by installing a Panasonic energy star rated 100 cfm bath fan on a timer set to run for 1 hour in the morning and 2 hours in the evening in the area to be ventilated (master bath or your basement room) with a 7" butterfly damper letting make up air into the laundry room adjacent to the dryer. The exhaust fan pulls air into the house through the damper in the laundry and out through the stuffy room. To get to 15 CFM per occupant times three occupant you need 45 cfm i.e. a 100 CFM bath fan running 45% of the day. But your code only says the fan needs to be CAPABLE of this standard, you can put in the fan and only run it an hour in the morning and an hour in the evening if this makes more sense to you. For filtering the incoming air we use aluminum range hood filters in a seven inch wall cap with the exhaust damper removed. by putting it next to the dryer we don't have to condition the 300 cfm the dryer demands when it is running. and it keeps the dryer from de-pressurizing the house and causing the fireplace to back draft.
Cheaper than an ERV and it works.
Michael
That's pretty interesting. Exactly where is the range hood filter located and is the box to hold it fabricated or "store bought"?
People up north may likely not understand these types of fresh air ventilation strategies so I'd like to add that this type of thing is very climate dependant and in mild climates like ours here in NC, a HRV or ERV are often times not cost effective - or at least the payback time might be 15 or 30 years, which could be the expected lifespan of the device.
I've also heard of air intakes behind the fridge - not that there is a need for air there, but there is a nearly constant heat source to condition the air - the coils on the back of the fridge. Obviously that only works during the heating season though.
The issue of a depressurized laundry room is something that is an issue in homes built in the US though, so I think I like your method better. BTW - I think the new mechanical code for NC requires a certain amount of ventilation to be supplied to every room containing a dryer - although I think a simple high/low through the wall pair of registers might be acceptable, which doesn't really solve the problem for the whole house, just the laundry room. I built some houses a year or so ago where the mechanical contractor did the 10" duct into the laundry room thing, but then the head inspector for that county (I called him) told me that it was not code required that the air come from outside.
Some years back I built 13 Energy Star (ES) certified homes. The fresh air intake was a 6" duct that fed directly into the return plenum of the forced air HVAC system. For efficiency reasons, it seemed counter intuitive to be constantly injecting outside air into the conditioned air, but these Energy Star guys had researched it and they felt sure it was the way to go. We had the manual dampers on the 6" duct cut way back though, and I later heard that the requirement was reduced to a 4" duct. One thing that was problematic though was that they wanted the filter located in a very accessible location - like in a closet - which makes sense, but is a little troublesome to implement. The houses were outfitted with an "aircycler" which was basically just a programmable timer that made the furnace blower come on even when the thermostat was not calling for heat/cool. The idea being that the air needed to be cycled 365 days a year - even during the spring and fall when the HVAC sys would rarely come on. I think we set them for 10 min per hr. One advantage to this approach was that the outside fresh air was fed to every room in the house (that had a supply duct).
I have 6 more ES homes coming up in 2007. I'll be interested to see what the ES guys have us do this time around... It is unfortunate that the average home buyer is unwilling to pay for this kind of stuff. Some limited percentage of whatever knowledge I glean during this next ES batch of houses will probably be incorporated into every house I build afterworlds, and probably a large % will go into the next house I build for my wife and I.
The lake "cabin" (about 2500 sq ft) my inlaws did in northern MN about ten years back had a roughly 4" piece of flex (20-30 feet long) feeding the cold air return duct, and I've seen similar in a few other recent homes near here.It probably doesn't make much difference how big the outside feed is, beyond a certain minimum size, if the house is tightly sealed. The feed will draw in outside air until the relative pressure in the house is equal to the pressure loss through the cold air return ducts, then you'll only draw enough air to replace that lost due to leakage at that pressure.Of course, this technique assumes that there is SOME leakage. An exceptionally well sealed house would require a matching exhaust.
Half of the harm that is done in this world is due to people who want to feel important. They don't mean to do harm but the harm does not interest them. --T.S. Eliot
I hadn't heard that one. Interesting, and very similar to what I was talking about, with the exception of the "Aircycler". It would be an easy retrofit too.
One thing that I learned through the work with the Energy Star homes is that ventilation and air circulation needs to be designed, controlled and field quantified. Hence, the previous poster(s) mention of ACH (Air Changes per Hour.) On these houses I did, the energy star guys not only did blower door tests to quantify air leakage of the structure, they tested the duct work for air tightness, the kitchen and bath exhaust fans for installed CFM, and checked pressure differentials between rooms with the doors shut. They also measured CFM or air being supplied at each heat register. Obviously, a small interior bathroom with no windows or exterior walls needs much less conditioned air supplied - and the damper was cut back accordingly. They measured the CFM of air coming in to the fresh air supply with the system running, and had us adjust the damper for whatever they wanted to see - CFM wise. There was other stuff, I'd just have to think a little harder. If I remember correctly I think they wanted <1.5% of leakage of the duct system, but the shocking thing was that they said that the average forced air system has 15 to 20% leakage.
In the old days, the idea was that the loose house provided some natural ventilation, although it was anyone's guess as to how much. Guys who preach this "tight houses are bad" I just look at like they are from space... :-)
Edited 1/6/2007 11:30 am ET by Matt
Here is the way we did it in one recent laundry room. The air is filtered through a range hood filter at the exterior air intake it runs through a weighted back draft damper in the cabinet in the laundry. We've also used butterfly dampers in a vertical orientation here and are looking at using a sleeve back draft damper I saw in re-williams. supposed to be quieter and more durable than either of the hinged metal style units. The homeowner will need to be responsible for cleaning the filter which is why we used the metal range hood filter as it seems most resistant to mildew and lack of maintenance. Next house I'll use the biggest hood/ filter I can find with a 6" sleeve damper. If you are in Raleigh are you using Southern Energy Management for ES? Are you doing anything with the Wake HBA Green Building Initiative?
So, the damper only opens when the room gets depressurized due to the dryer running... I'm still not sure I understand the range hood thing though: In your pic, that is a standard item that the range hood slides/clips in? The reason I'm so interested is that I need inexpensive and easily implementable solutions. In the past we had to have the filter element housing fabricated which was a little pricey.
Re your 2 Qs... it's a No and a No. I believe I will be working with a company called Advanced Energy on the upcoming Energy Star stuff, but maybe I should check with the other outfit you named? Advanced Energy is great, but the certification process is quite expensive. I looked up Southern Energy Management on the web and just sent them an E-mail.
The exterior filter holder is converted from an 8" range hood flashing from CC Dickson cut the hardware cloth over the bottom back to allow insertion af a range hood filter and tape the flap damper out of the way. the interior Back flow damper shown is not ideal, we'v used it and it works but will switch to the sleeve damper http://www.rewci.com/noname6.html on the next project with the bigggest filter hood we can find. The damper opens whenever the house is de-pressurized for any reason. So the dryer will open it but also the energy star bath fans will pull air in there from across the house and under doors. To get 7.5 cfm per occupant out of a 100 cfm bath fan you need to run it 7.5% of the day per occupant. adjusted for the amount of the day the occupants are actually in the home. generally an hour in the morning and an hour or two at night will do the trick. We feel really good about Southern Energy Management. not only do they do energy star certification, they also do our Green Building Initiative certification and provide solar hot water and PV. Great folks to work with.
When I remodelled my basement in Acton, MA a few years ago, I had the same issue (insufficient amount of glazing, need to put in mechanical ventilation). The Building Department said that putting a device such as Inforcer from Tjernlund would satisfy the requiremens. I was able to procure one from the internet for a couple hundred dollars. It has a built-in timer so that you could set it to go off at certain times of the day. I put a manual switch on it in order to control when it was on.
I suspected that the glazing/ventilation requirement was because I made the basement livable space. If I had said on the permit that it was going to be "storage area", I would not have had to deal with that requirement nor the 7' height requirement.
Note that the definition of "liveable space" may depend on factors such as whether outlets are installed, floor and trim are finished, etc.
Half of the harm that is done in this world is due to people who want to feel important. They don't mean to do harm but the harm does not interest them. --T.S. Eliot
To get back to your Q I think a lot of your issue depends on how your individual inspections dept wants to interpret habitable space. For starters look up "habitable space" in your code book definitions chapter - quite possibly chapter 2.
One thing kind of odd is that here, in NC, the function of a space is determined by how it is labeled on the plans. So, a finished portion of the basement labeled storage could be exempt from glazing and ventilation requirements. As always, this is dependant on interpretation of code by your local inspections dept. These guys nearly always get their way.
How does your county/state define 'Habitable'? In my county, habitable space is space that is heated. When you permitted the basement project, did you define these areas according to the habitable space definition for your area?
Theater Room, Gym Room, Bathroom.
Yeah, conditioned space, and once you start putting outlets, lighting and switches in............
This has been an education for me. I've read and heard "about" these systems, but never had to spec one out nor have I seen one installed.
We have an HVAC guy on the case. It was a blatant error that the BI did not catch it on the plans prior to permitting the job.
It doesn't look good going back to the client now...............some knowledge of the code book or at least the posession of one in the office might help a bit. That is out of the range of my responsibilities so................just hit the client up for about $2000.00.
That oughta do it![email protected]
It's Never Too Late To Become What You Might Have Been
hello,here's how it works north of the 49th parallel.All newly constructed dwellings must have a" mechanical heat recovery system".My beef is as follows.Windows don't count as ventillation.These systems don't recover much heat.Typically in new construction the fresh air intake is installed in the soffit where offgassing from paint or vinyl soffits/siding is most highly concentrated.If your neighbour idles a diesel truck in his driveway or sprays his lawn or runs a woodstove,guess what comes in your "fresh air" intake.These systems are intended to run full time automatically.If the system isn't neutrally balanced,it will either pressurize the house,possibly forcing moisture through the interior walls,if negatively pressured,you get drafts.
Having said all that,can you imagine how rank a workout room would get without venting?With just an exhaust fan what if the air you're drawing is no better than the air you're exhausting?
Windows wherever possible are the best solution.I wonder what kind of house plan provider wouldn't know about ventilation requirements.Especially in a basement bathroom or workout room.Good luck
I can't disagree with much of your statement.
Windows wherever possible are the best solution.I wonder what kind of house plan provider wouldn't know about ventilation requirements.Especially in a basement bathroom or workout room.Good luck
Here, windows do count, but operable at will is hardly the same as a venting system on a timed switch! So, I can leave the windows shut forever, never open them if I choose not to, but you will require a ventilation system that must run on a timer or sensor type switch?
Plans were drawn by our in house Design Architect. I never knew until recently that DE was an official title.
Eric[email protected]
It's Never Too Late To Become What You Might Have Been
Truthfully,I've never looked one over closely.The jobs I've worked on had h.r.v. guys come in usually after the rest of the trades have had their kick at the can.What I have seen are units that are totally automatic,two fans in a box with ductwork,and plugged into an electrical outlet.A provision must be made for condensate.The other unit I've seen,often as a remedial fix is a "humidistat".As the name suggests,it controls humidity with venting and is operated by a wall mounted thermostat type controller.I don't know if it qualifies as a "mechanical ventilation unit" as per the building code.The code implies some sort of false security to home buyers/builders "if you build it by code,all will be well for ever and ever.." That just ain't always so.
The new fear up here is mold and maintaining a proper indoor environment is the best defense against it.
One thing you gotta realize is that this stuff is highly regional. I hear ERV/s, HRVs are popular or even required in Canada, but around here (southern mid Atlantic USA) I'd bet at least 50% of licensed residential builders don't even know what one is. They are required in commercial/public buildings though.
around here (southern mid Atlantic USA) I'd bet at least 50% of licensed residential builders don't even know what one is
Pretty sure you could bump that up at least 30 points here. Buddy had great trouble here finding an HVAC sub who knew what one was. His GC couldn't find one.
I warned him he shouldn't be talking to me. Got a better house, but he had to earn it.PAHS Designer/Builder- Bury it!