GRB1100 Module 2 Green from the Ground Up Chapter 2

0:06 in this second chapter we're going to learn that the home is a system of interrelated parts and again this first image is relatively important it just kind of gives you an insight or a look at what we're about to learn when the shower leaks or there is no ventilation fan in the shower it creates condensation that condensation can lead to mold and that mold can affect indoor air quality a roofing problem can drip into you know the indoor environment plumbing leaks can lead again to you know deterioration of the frame deterioration of the home mold uh likewise in inadequate kitchen

0:52 ventilation think about burning with propane or natural gas you're literally putting co2 gases into your home moisture transferring through like the basement concrete floor and or walls if you live in a home with a basement in the northeast united states radon gas is fairly common in the home but it's it doesn't need to be there that's like an example of you know um spark smart building or building smart sustainable building green building thinking about all these things before you build and not just putting together a house as quickly as you can as cheaply as you can because you're gonna occupy that home for 50 to 100 years where people could occupy that

1:39 home for 50 to 100 years and if it's leaking rate on gas that could lead to cancer those traditional fireplaces are are are quaint and traditional but they really have no place in today's modern home they they leak uh um fresh air can go in or out of those and out in or out of the flu but really what happens is once you burn a fire in there now you have creosote in there and so whenever you open a window uh air might actually come down the chimney and you're breathing that creosote so the home is a system of interrelated parts that's what we're going to learn about no one home is typically built the same yes maybe in your neighborhood a builder

2:26 built a whole bunch of homes the same but as you move throughout the country throughout the world every home is built differently and there's different reasons you're going to build to your environment or you should build and so building science tells us you know in very cold climates like northern maine you're going to insulate more and you're going to build for cold weather in florida you're going to be building for hot and humid weather you might even build without a basement because you there's just going to be too much moisture in that basement in a really damp humid environment and so you always build to your environment no one home would be the same you're going to use different heating and cooling systems based on where you live if you're in let's say

3:12 florida or texas southern texas you're really primarily worried about cooling and you're going to really focus on uh as far as heating and cooling goes a cooling system and not so much heating but in northern maine again it's going to be all heating and very little cooling maybe just opening windows so again your house is a system you got to think of it that way air leaks and building science go hand in hand so when you turn the dryer on a forced air dryer and it pulls air in from the basement to dry your clothes and then it forces that moist warm air out how did the air get into your basement if you just keep drying it out it has to be replaced with air air is going to come into your home typically through air leaks so are those air leaks underground is

3:58 pulling radar great radon gas in is it pulling moist uh moist moisture in you know moist air in is it pulling it from your attic that might be heated in the summer because you have really dark shingles on so you want to just be aware of air leakage though and how it's getting in typical places will be uh like like duck registers will leak attic hatches will leak recessed lighting leaks uh again if you are building uh in a sustainable way in a greenway you're caulking and sealing all of these the ductwork the recessed light fixture in a traditional home those are not sealed up they're just leaking into the attic other places where air leaks is around

4:44 windows that top plate crawl spaces can can leak air and so again using green building theory building science theory you are going to pay attention to all of the details in the last slide we discussed air leakage and air moving in and out of the house or the building this slide we're going to understand or look to understand that moisture can be moving with that air or moisture can physically be running into the building so number one could actually just be rain falling on the roof leaking in windows or ventilation could be drawing the moisture in or out or you know in and through the building creating a damp interior uh you could have

5:29 leakage like through the windows you can be moisture is going to reduce the life of those windows because moisture is just constantly being drawn into the home think about the that that vent over top of the stove you turn that on while you're cooking but you're drawing air in how does that air get in it could be warm moist air being pulled in uh you could have water just soaking into the foundation into the structure just from it's called capillary uh and just drawing the water in or it just could be soaking through the material think of water like water's not really doesn't repel water like wood i'm sorry wood does not repel water if you soak wood into water it will physically get wet and so over the life of a house that could be happening and rot and mold can happen

6:15 in some homes or building electrical resistant heat is the only way that this the building or structure is heated and so if you think about where electricity comes from it comes from coal oil natural gas power generating plants it could be a wind farm it could be a solar plant but in this slide we're thinking about heating and cooling and specifically we're looking at heating and so when that heat is lost because of poor insulation because of air leaks we're wasting resources and in this slide you can see that by the time electric reaches us it has lost roughly 85 percent of its potential energy

7:01 of the coal that it was used to mate to make it if we heat with electrical resistant heat we're only getting 15 of that energy that the coal had to offer in the first place so this is you know could be a hard hard concept to understand but if you think about you know electric being generated by coal which is very polluting adding lots of greenhouse gases lots of co2 lots of emissions it's the whole process is very wasteful there's an inefficient generator there's inefficient transformers you're losing electric as it's being pushed to your home and then when your home is not really built in a sustainable way and you're just wasting the heat it's just continuing that that what we've learned that homes and buildings use 40 of the electricity united states

7:49 when we select very efficient heating and cooling systems that is a form of green building on this slide we have an example of buying a heater that might only be sixty percent um afu versus 98 and so that's just a form of annual fuel utilization and so that at a sixty percent that means sixty percent of the heat generated by that furnace goes into the house and forty percent goes up the flu uh a ninety eight percent furnace means um ninety-eight percent of the energy goes into the home and one percent uh one to two percent actually ends up going up the flow and so yes the more efficient furnace actually costs more but look at the

8:35 savings right there on the right now and that's just based on a u.s national average when i grab this slide in five years you can save almost four thousand dollars in ten years almost you know seventy six hundred dollars and if that furnace continues on for 15 years you're gonna you could save as much as eleven thousand dollars that's far more than the cost of that furnace the difference between an inefficient furnace and a high efficient furnace in this presentation we're thinking of the home or house as a system so when you have a choice you could either use electricity or natural gas to power and heat or you could use the sun's energy to passively heat your home and so by designing your

9:22 home facing it towards the south you know building appropriate overhangs appropriate amount of glass not too much not too little you actually can build a more sustainable home that requires less energy input which is you know getting energy for free there are three methods of heat flow conduction convection and radiation conduction is like heat moving through a solid object convection is a movement in liquid gas that might be like steam in a shower converting to the air like from air from water to air and radiation is the movement of energy in waves from hot to cold so we're going to explore that more in the next few slides

10:10 let's explore what conduction is conduction is heat movement through solid object a good example would be your roofing material the sun in the middle of the day the sun shines down on your roofing material uh the sun's energy is heating up that material that heat moves through into the attic so when you climb up into the attic in the middle of the day it can be really hot up in there that's conduction but every material has different resistance to heat flow so when we put insulation into that roof or ceiling or attic we can actually slow the heat transfer down and so the difference between wood and insulation is is great you can have great differences of how much heat flows and so that's why we insulate insulate

10:56 actually slows the movement of conduction and so again different materials have different rates of movement so wood metal cellulose that's like paper um have different forms of uh insulation so in the image here you can see that um there's a wind pitch of a window and there's thermal heat loss it's called the u-value and you have the inside of the window and outside the window and depending on how the window's made you can see how you can build the window in a way that he is reflected back into the home as well as heat is reduced coming in so in the northern climates you actually want to let a little bit of the heat in but in the southern climates you really want to keep as much heat out so again there's different strategies in building and again that's green building and

11:43 building science and you think people do that but it's really not as common as you think people go with the cheapest window they can find and ignore these simple things convection is the movement in liquids and gas that heart rate in this image you can see like a radiator that's being warmed by a steam um furnace boiler and so as that radiator becomes warm hot air rises that's convection hot air rises hits the ceiling but there's a cold window on the other side of the room that cold air is now creating a drop the cold air falls it goes back to the radiator and then the air is warm that's convection that moving air is called convection another example of convection

12:30 might be the steam in a shower when you are taking a shower the water is running you see steam in the air well where does that water go that's now floating in the air when you open the bathroom door there's your bathroom's all steamy if you don't have a fan where does that go that because it gets converted into the air it's adding more moisture to the air and that can lead to it poor indoor air quality if you have lots and lots of moisture in your home and radiation is our last heat flow method radiation is like the movement of energy in waves from hot to cold in line of sight that good old wood stove wood burner traditional fireplace that heat coming off that is radiation and here we have three examples of

13:16 conduction convection and radiation if we apply what we are learning is being able to build the exact same home in new orleans new orleans and alaska a good or a bad thing we know it's a bad thing they're not going to be the same and so besides considering heat flow what else could we consider when determining our design as we wrap up discussing heat flow we understand that a home built in new orleans and alaska are not going to be the same thing but what are the things that we want to consider and that would be you know where is this building being

14:01 built how far north of the equator is it being built you you might know this but maybe you just haven't thought about it so if you if you're on the equator the sun goes right overhead uh in the middle of the day but as you move away from the equator 10 degrees north as you move away from the equator and you're moving towards florida for example i think florida is around 20 degrees latitude roughly the sun is not directly overhead and then as you move further into new york you were at like 41 42 degrees that means the sun is never really overhead it's it's a little bit at an angle and then as the seasons change uh like in the winter uh here in new york the sun never doesn't really get overhead at all in the winter and so

14:47 understanding uh your northern latitude will affect how much sun can get into your structures you're going to design your structure in a way with overhang with overhangs in a way that allow the sun's energy to get in in the winter and you want to block the sun's energy in the summer and the further north you go or the further south you go will change the depth of that overhang so you can't just say a two foot overhang is good that might apply to say roughly you know new york but that you know but that depends on where the window is placed on the wall is the window placed high or low on the wall so every building is different every location is different as we think of the home or house as a system we're going to revisit air

15:33 leakage so not only an energy concern you know air leakage is not only an energy concern but more importantly it's a moisture concern because if air is leaking into your home there's a really good chance that it's bringing moisture with it and and so that water vapor that's getting into your walls into your drywall into your plaster is a problem and so does regular building codes have a requirement for air leakage amounts the answer is yes what are some methods for evaluating air leaks you're about to see a blower door

16:19 does regular building code have requirements for air leakage amounts and i already told you the answer is yes so in the image you can see you know air coming in one side of the house and kind of blowing through and being pushed out the other side i think i have some images here but just picture the wind blowing outside and that actually just puts a little force on that this left side of the wall and a little bit of air might seep in well once air seeps in then some other air has to push out and so here in new york currently but this code is changing it changes um often and depending where you live there's different codes the 2015 building code in new york is five air exchanges per hour or less that means all of the air in the home can turn over

17:06 five times per hour to be considered code when a new house is built a blower door is one of the very best ways to evaluate air leaks a blower door is a device that you put in your home for inspection purposes only it's how you find out if your meet code at five air exchanges per hour you basically place this soft device like curtain in your doorway it gets kind of sealed up with a frame and some velcro and a plastic sheet with a fan in it you turn the fan on and you can actually determine your cubic feet per minute moving through the home and so that blower door is a device you can

17:51 compare different homes but you can also see if you meet code and as you continue through your green building experience this is something we have in the classroom that we can actually go out and do in the field over the next several slides we're going to learn about ways of stopping air leaks we're going to learn what an air barrier is we're going to learn to learn what stack effect is and what flu effect is so what is an air barrier an air barrier is something that stops the air from flowing through the wall in traditional building if i were to have a slide of that or a picture of that you would see 48 sheets of plywood with a gap between each piece of plywood that's how we built homes that's how i built homes 30 years ago whenever

18:37 you know i was just working um more as an apprentice today there's products like this zip product the wood is covered by the zip product you have tapes that keep the air from flowing between and the image on the right you can see a very detailed understanding on how caught concealing is used to create an air barrier to stop air leaks as we learn more and more about green building theory building science theory we learn to be aware of things like stack effect and stack effect uh is supported by air leaks so an image on the left we have what's called like a wind effect not quite stack effect but wind effect when the

19:22 wind blows on the left side of the home uh small leaks around windows and doors and vents allows air to leak in and what happens is that it basically is just pushing air in on the left and then it gets pushed out on the right because air is coming in on the left and the neck the low pressure is on the right side of the house in the middle there we see stack effect it's really obvious in really large buildings when you try to walk into a really large building you go into the lobby the building you open that main door sometimes you feel a big whoosh of air that's a stack effect happening and what it is that's like a negative pressure on the lower floors and then you have a high pressure on the upper floors what happens is air gets sucked in from lower floors kind of rises through the building

20:08 through the elevator through stairwells and then it gets pushed out on the upper floors and then lastly you have combustion combustion and ventilation you can see on that image you still have you know you burn the fireplace you might turn on a vent over your stove you might take a shower turn on a vent fan what's happening there is your your your your drawing air out of the kitchen to get rid of the smoke or the you know contaminants of of cooking and but that air has to be replaced somewhere so where is that makeup air coming from it's coming through air leaks in your walls windows and doors

20:53 in this overview we're learning about how the house is a bunch of systems put together they everybody every every system is related and so we have to be aware of the flu effect and again these are things i was just talking about where that traditional fireplace always has a connection between the inside and the outside yes you might have some kind of flu door that you can shut but if it doesn't shut so tight like if it doesn't have a rubber gasket it can leak and so there's no flues out there with rubber gaskets because they would melt and so um that's what's called the flu effect you're always going to have air either going in and up the chimney are possibly in and down i've had that problem with my house when my forced air furnace kicks on it actually draws air down the chimney to the point where i had to actually block it so that i wasn't br my

21:41 family and i weren't breathing creosote and so there's air leaks caused by the flu effect just by air naturally rising out of the home hot water tank bathroom fan furnace traditional fireplace airs rising up those fluids those chimneys and it has to be replaced by makeup air that's coming again moist air might be coming in through windows through cracks radon gas might be coming up through the floor things to be considered and so we use building science green building theory to stop that from happening so i just said that we're going to try to stop air leaks by using green theory green building theory so now we've tightened up the home

22:27 but we now we need to ventilate because if you make a house too tight then those contaminates from cooking cannot get out moisture from the shower cannot get out so why seal up a home so tight that now you have to provide ventilation instead of just building the home with natural leaks through the building envelope well the answer is we want to stop that moisture from coming in we want to control the moisture we're going to bring them we're going to bring the fresh air in using devices like ervs and hrvs we're going to we're going to get the moisture out of the air and put that that drier air into your home as we're building these really tight homes currently and there are three types of ventilation that we're going to review in the next few slides three types of ventilation are natural

23:13 ventilation spot ventilation and whole house ventilation and so natural ventilation is opening your window spot ventilation might be drawing air in from outside and and distributing it like just into one location say you know an upstairs bathroom and then there's what's called whole house ventilation which i already talked about like hrv and you can see that image on the right there's a picture of a house bedroom bathroom laundry kitchen we have there are some interconnected pipes and you can see that we're drawing on the right side we're drawing fresh air in uh it's mixing with air that's already in the home and so this is something this is a device that actually run 24 hours a day seven days a week

23:59 on a and a really tight home and these are very common on our new homes passive houses are as a is a is a term that we haven't talked about passive houses are really energy efficient very energy efficient um leading the way and saving energy but they need to be ventilated because they're so tight so fresh air is brought in mixed with the stale air some still air goes out gets exhausted that's why you can do it in the winter because you're maintaining a lot of the heat in there and you're just bringing in a little bit of the fresh air you distribute that fresh air um like into a bedroom if you're you're putting fresh air into bedrooms living rooms and you're drawing stale air out of the kitchen so you're taking you're taking air out of the kitchen where you might be cooking out of the laundry room

24:44 out of the bathrooms there might be moisture and you're taking that air and pushing it out that's three forms of ventilation natural ventilation spot ventilation and whole house ventilation we've been exploring different ways to manage air but now let's explore managing water so water can come in three forms solid which is like ice ice can can destroy homes uh in the winter liquid would be just think of water uh running in through like a roof leak and then gas is for example um the moisture in a in your bathroom or in a shower where you're taking a shower um where that moisture then goes up in the air and turns into a gas how do we deal with that in all of its different forms well naturally we want to

25:29 ventilate it out we want to stop those leaks and we do not want ice to form and we can do that in different ways proper insulation and not allowing heat into the attic we can stop ice from forming and dripping off the edges of the roof you know properly installing uh roofing systems that last a long time stops water leaks and installing them properly and not having really good ventilation and wherever you're taking a shower that can remove some of the water moisture um water vapor is something to consider so water vapor moves either on air or through material and so you can have air barriers but they're usually rated it's called a perm rating and how much

26:15 how much air can actually move through a wall or through an air barrier is based on the perm rating and lastly capillary action this is just water wicking up through material and so when you see you go into a basement and it's wet that could be because of leaks or it could be capillary action where the water is just physically soaking through the concrete and working its way up into the basement and so we need to be able to manage all that we need to keep water away we can do different landscape landscaping techniques to have the water move away from the basement and we can actually physically change the way the basement is built to keep water from wicking up this is what water management looks like rain outside

27:00 tree roots could be putting a little bit of pressure on foundation walls and floors you could have cracks in your floors and hydrostatic pressure just causes the water to want to fill up your basement fill up that crawl space and those cracks can turn to mold and then that moisture that's in the basement now tries to work its way up through the walls through the the the floor joists and so we want to deal with uh water at its source you know stop it keep it outside of the building french drains and things of that nature and this is how we deal with water properly um

27:45 the landscape the earth is sloping away from the building the house's siding is set up in a way that the water is dripping away from the foundation there's drainage involved and so this is just the details of how to build a green home or green building properly and i end this overview with some questions we've been learning about the house as a system so um if we have a really tight home and we have multiple exhaust fans that sometimes can be a good thing because what we're doing is we're exhausting the still air we just need to

28:34 supply the fresh air does it really matter what type of heating or domestic hot water systems we use yes it does as we make tighter and tighter homes we do not need large btu really strong heating and cooling devices will the amount of exterior foam have an impact on the wall performance and durability of course it will so as we increase exterior foam on the outside of your home you're actually going to increase the performance uh you're going to repel the water you're going to keep air and moisture out and it's going to improve durability because your walls are going to be dry well installing poly that's like plastic inside wall matter it can yes i've seen homes built with uh wrapped on the inside with plastic but in most

29:21 cases it's not the preferred method yes that will stop air flow from getting into the room but what it really does is it creates areas of moisture possible moisture and lastly we'll find we'll end the overview on this house as a system installing carpet wall-to-wall painting those walls with traditional paints is going to be bringing in voc levels many cabinets and flooring have formaldehyde as part of how they're being made and held together the glues have formaldehyde in them so as we create these really tight homes but then we go ahead and paint the walls with non-sustainable or traditional paints we can actually create a really

30:09 uh toxic form of indoor air quality and so we've been learning about the house as a system and we've got to look at all the different systems and how they interrelate i hope this overview has helped have a great day