New BUILD : Excellent Air Conditioning System Cost? I’ll tell you!

we are back at that 1914 passive house remodel project now if you missed the last video there's a link in the description but we talked about insulation and air tightness and how this house basically has double the insulation value of a standard code build house but on today's build show we're gonna be talking about the mechanical system how do we heat it how do we cool it how do we bring in fresh air and we're gonna talk about how much it costs on this house and what you might want to budget for a good mechanical system for your house let's go up to the mechanical room and meet Miguel from positive energy okay guys we're up in the attic mechanical room here and I've got with me Miguel Walker from positive energy we go you guys are a building science and mechanical engineering firm you've done all my work for about the last ten years designing my systems that's right but we are not in one of my houses this is the same house we talked about before that's a going to be passive house rated house clean tags the Builder here Forge craft architecture is the architects and this is actually Trey's personal house who you met on the last video but tell me about this passive house standard that we're talking about today yeah passive house is an amazing standard it's well beyond code it's a high-performance metric space outcome-based standard that is really aimed at making sure you have a very durable house that lasts a long time with a very healthy indoor environment and the folks at clean tag and forge craft were phenomenal to work with it takes a lot of design and a lot of thinking to accomplish those things so getting in early and really having a good team makes all the difference in the world and they were phenomenal to work with yeah now this one's not rated yet but what system will this be rated under that's right so passive house has kind of a colored history in the United States it especially when it comes to the hot humid south it didn't get the uptake that I think a lot of folks were hoping it would because it required more insulation than was really necessary for our climate zone and so Trey's house is participating in the 2018 standard he's one of the pilots for that that new standard and it's much more climate specific so you're not over insulating for a house that you would let's say in Minnesota or Ontario we're making more of a southern based insulation packets right still very tight air tight standards and still very strict energy standards that's right absolutely good deal now with that being said talking about this mechanical system yeah we've got an amazing enclosure here we talked about that last time really double the insulation value that code would require tons of triple glazed windows just a really bomber enclosure also very very air tight here now what do we need to do for an enclosure like that in terms of mechanicals well so the enclosure is gonna dictate how the mechanicals need to perform and the air tightness is a big part of that in passive house so you really need to think about how you're going to keep the occupants thermally comfortable how you're going to keep the air healthy and filtered so normally comfortable that's the temperature right those we're gonna satisfy the thermostat that's right and keep going and what is what were you saying about comfort then as well so comfort is beyond just the way that we experience what the thermostat says it also has to do with the quality of air that we're breathing in and that we're swimming around in virtually all the time yeah that's right so our system here actually takes into account all of the elements of thermal comfort and human health and puts them in one convenient well thought-out package all right so that being said talk to me about the big black box which is doing the heavy lifting on thermal back here absolutely so this is a vrf system made by Mitsubishi you've featured their equipment on many Abbey's a lot of one of the best things about vrf systems for tight well enclosure houses like this is that you have ramped down capacity so you're not blasting a ton of cold air in the space just to satisfy what the thermostat says and then running into humidity elevation issues by over cooling it's able to ramp down as it needs to and just coast yeah so in a really good house like this even on hundred degree days let's say it's gonna take a long time for the house to heat up that's right if this was a single stage you only have let's say if it was three tons thirty six thousand BTUs going on or off two-stage unit maybe it could ramp down to sixty percent but the big deal on vrf we've talked about this before as it'll ramp from 15 percent up to a hundred percent so it could run at ten or fifteen thousand BTUs or maybe twenty thousand or 25 or 30 depending on where the loads are absolutely which means it doesn't need to blow this massive amount of cold it can kind of puff in where necessary absolutely and if tray has a party you know Thanksgiving family over something like that there's a lot of cooking going on in the house this is more than capable of handling that extra load as well Nomex ounce now what's the big white box we got above here so we live in Austin it's a very hot humid place and we have long shoulder seasons so during the spring and fall when this machine here isn't necessarily running and keeping the air as dry as it needs to be we have this it's an ultra air dehumidifier they're a phenomenal company based out of Wisconsin american-made product you're us they're there they're fantastic and for those shoulder seasons it's going to do the heavy lifting that this thing can't so this little box right here 70 H means 70 pints it can remove out of the air that's right in 24 hours it's gonna dump it down that condensate drain which is gonna backside there and then it's gonna dehumidifier but it's also gonna drop some heat in today right because the compressors inside here that's right so you need to consider when you're designing a system you have to think about where this extra load is gonna be and distribute it across a whole house it's not a significant dry Bowl to add to the house and because it is dryer air even though it's warmer if you're gonna run into less of a comfort penalty there but since the great thing is that you know this system is designed to cool a space as a random side-effect of that the compressor in the fan will dehumidifier this system is designed specifically to remove humidity from the space so the compressor and the fan are designed to handle that load yeah the interesting thing about this system to go and where you design here really pretty simple system we're a little more than two thousand square foot house mainly single-story with just a little bit of second-story here and this one system can do the entire house that's pretty cool absolutely and one important thing we should talk about on the return side of the system is the filtration right so we've talked about keeping people comfortable so we talked about keeping the air dry made insulin right here that's right so this is the IQ air perfect 16 tell me about this thing this is a phenomenal filtration system it's a Merv 16 system and you can see we've got pleats on pleats on pleats so merv 16 that's like hepa quality that is a HEPA grade filtration so you're getting down to the PM 2.5 level of filtration which is all of that stuff that gets in our lungs that we can't get out that our bodies can't filter out so this is doing the heavy lifting from the filtration perspective that's cool hey we haven't talked pricing yet let's take a second to talk pricing because I know people watching or curious how expensive this is what this would cost in their house typical new construction where people aren't necessarily doing things well what is a builder spending on an HVAC system you know we see a lot of one to two percent total percent of construction costs and that's just abysmally low we're talking about flex runs that are just really shoddily done and so in a million dollar house we're talking about grande exact system that's oh yeah and you know I don't think it's super necessarily a byproduct of laziness so much as it is profit incentive right so people want to get the job done fast they want to get on and move on to the next job and they don't know any better right I mean this equipment you have to think about it you have to specify it okay so in contrast that that one or two percent what are you guys telling people a system like this should cost if you're budgeting for yeah construction or remodel that's a great question and even Passivhaus standard we try to set expectations very early on in the project which is why it's great to work with an architect you know when they're still in concept phase trying to figure out what the house is gonna be you can help set expectations by talking with architect talking with the client and making sure the Builder knows the implications and we're seeing between four and seven percent depending on the house okay so 40 grand is 70 grand let's say on a million dollar budget that's right yeah the bigger the house gets you're gonna see some roll-off on that budget number but the for smaller houses it's certainly gonna represent and occupy a larger slice of the pie than I think a lot of people are used to but that's that's part of change that's part of the friction that comes with stepping up the game and requiring better quality that makes sense my guess is this house is five hundred to a million or so sound right construction costs so you can do the math yourselves at the very lowest four percent I would guess to the system like this is probably more like five or six percent though the smaller the house the smaller the budget the higher the percentage overall it needs to be to get good equipment now we haven't talked a lot about ducks yet and Miguel yeah but tell me about the duct work that's that's going on here it looks to me like you've got a lot of metal we absolutely have a lot of metals so a part of that that budget range that we're discussing is includes all of the upgraded boxes I think that a lot of people aren't used to yeah but it also includes our design fee you know it includes the Installer overhead and it includes upgraded distribution because frankly the distribution is the most important thing that you're gonna run that you need to accomplish for a good system and I'll brag on these guys a little bit you know when you hire a firm like these guys and there are some other good firms out there doing the similar kind of work you're actually going to get a layout that they've talked with the structural engineer so they've designed this for this particular space for the house for the type of framing we're encountering they're showing the Installer exactly what they need you know this is a 12 inch round rigid duct they're showing where they can run some flex and they've got flex in the last maybe 10 feet on some of these runs to quiet it down that's right they're showing a little more flex in a return side than on the supply side so these guys do a great job of specifying that and it's worth spending the money designed ahead of time and not just doing a design build like is typical on American new construction well and as you can see in this attic space you know we got in with Trey very very early and so he was able to provide a significant portion of the attic space to actually work out the mechanicals and in modern construction where you have the you know form factors that don't necessarily allow this sort of thing having a design is absolutely critical because your tolerances are a lot lower and you really need to make sure that that space is going to perform in a way that keeps the occupants comfortable and keeps them healthy so getting involved early makes a huge difference and having enough space advocating for that space early on is a big deal that's huge hey before we move on to one of the cool system I want to show let's talk about costs for a vrf system whether it's musubi xi or LG or Dyken how much more are these then a standard you know traditional system shall we say you know frankly we're seeing a lot of competitive bids between the higher-end two-stage systems and vrf systems it entirely depends on your market and frankly if we're if we're talking about let's do one thing right I don't care so much about the box I think these are amazing well engineered systems yeah but get the distribution right because if you don't get the distribution right that's stuck in the house forever and it's very expensive and inconvenient to tear out yeah I mean your ducts gonna be there three or four times longer the right box which might get replaced in 20 maybe 25 years your ducts are gonna be in there 7,500 years that's right get replaced so if you if you have a cash flow issue on your project and you need to you know leave one thing out put something in first go with the ducts you can always upgrade the box later but if you've got it this is a phenomenal piece of equipment to put in it's great for energy it's much more accurate for thermal comfort and frankly the life ban of these units was very long so yeah you've got a great return last thing on the D Hume you know most projects in the south do not have a D Huez Becht so this is a cost adder for most builders out there what can you expect on the d human stalled can you can you give any range of pricing you know the box itself is you're gonna run anywhere from a grand to two I'd say for kind of the average typology but not having a D humidity still exists in the air so if you're not treating it you're just ignoring the problem right frankly these are a must have in any hot humid climate in my opinion I don't I don't build a house without stalling wanna get more so one to two grand for the equipment of cells remember your HVAC contractor needs to make profit on that he needs to install it he needs to supply it so you you're probably going to budget maybe three to five grand for a do that's right depending on the size of the house you might need to but these are amazing units all right so we've talked a lot about heating and cooling filtration one of the comments I get a million times on my youtube channel Miguel is that you're building these house is too tight people are gonna die in there yep what have we done about fresh air in this house well I think it's important to note that you do not have a long trail of dead bodies on your projects that's right it'll be tight houses for a long time building tight essentially eliminates all of the nasty stuff that can occur in the wall cavities right yeah so what you're doing is you're just centralizing and controlling where the ventilation air comes from that's right in old houses people thought that they needed to breathe primarily because they needed to dry right your wall would get wet it needs some way to dry yeah and we have amazing wall systems amazing enclosure systems that are designed to dry to the outside if I need to right so by making this a really airtight space we've done what you should do and provided an ERV which controls the ventilation in a balanced way in the house Miguel just to summarize build tight ventilate right you know people who say we should build looser houses they just don't get it right if we were gonna build a loose house we might as well just leave a window open in the house that a homeowner can never shut that's the same as building a loose house we want to build the tightest house we can of course we have operable windows so if the power goes out they can open their windows and have some fresh air but that being said we've got a really smart ERV system in this house so walk me through how the ERV works on this house absolutely so an ERV stands for an enthalpy recovery ventilator or it's more commonly known as an energy recovery ventilator yeah and the reason it's called that is because it actually does recover a lot of the thermal energy that you've already paid for we have a thermal comfort system to keep in the house yep you don't want to just bring in hot humid air that you're going to essentially lose all the money that you just spent so in the South we use an ERV rather than an HRV the HRV is just recovering heat meaning in the south or in the north where that you're often bringing in cold air we're gonna mix the air streams in this core so that we're moving some of the heat and it's tempering that cold indoor air that's right but in the South we're typically dealing with humidity outside and so it's moving those air streams and it's moving a little bit of humidity from the indoor to the outdoor remember though it is not a dehumidifier so most of the time what I do is I use my dehumidifier for fresh air and the ERV is the next step beyond that if you've got a Adi human then this is the next step beyond that so walk me through how this one works on say oh yeah you're absolutely right you need a dry cool air mass right so you're gonna have an intake and then that's going to go across the core yep to a supply now and that supply is gonna go to every single room yeah then you're going to have an exhaust from the return that you you design in your ductwork and that's going to go through the exhaust in that actually dumps outside of the house gotcha and so what's amazing about the Panasonic ERV is that it has two different fans in it that you can vary the speed of so you can tune it a little bit tune it down to the exact kind of positive or negative pressurization that you're going for which here in the south hot humid South we're almost always positively pressurizing slightly to push out those those pollens and allergens from the areas of leakage that there still are in the enclosure the thing about this one I like is pretty small pretty straightforward nice replaceable or cleanable filter absolutely and frankly pretty reasonable on cost from what I've seen these things run just for the unit themselves like under 1,500 bucks that's right that's pretty nice compared to some of the more expensive ones which have greater capacity of course so walk me through where we're pulling air out of in this house so the ducts we have a dedicated distribution system for the CRV and so it it doesn't have a home run system but we have designed return side of this and a supply side of this that's going to each room in the house and then we've tuned the fans to make sure that that is positively pressurizing the building very slightly it's not it's not a lot it's not gonna make your ears pop when you how many CFM do you think we're talking about forgetting it like this how much is it moving so you can see here the fans can actually move up to 100 CFM English both exhaust and supply gotcha so we're not talking about massive amount of a or 100 CFM out 100 CFM in at the max and you can tune that based on your size right this 2100 square foot house may not need 100 CFM maybe 60 would do it for this out that's right an entire leap in your engineer will be able to tell you exactly what you need and one of the great things about this is that when you have a dedicated distribution system for it it's not a huge cost add because you're talking about much smaller ductwork than you need for the larger fans yeah these are small 4 and 6 inch ducts that's right and then each one's running into a bedroom so as you're sleeping at night you're puffing in a little bit of fresh air to each one of those bedrooms but that's not fresh air like your windows open fresh air that's your cool dehumidified and in this case thoroughly cleansed air because you've got that HEPA quality filter that's right and you've got a filter in the ERV you've got a filter in the dehumidifier and you've got a filter on the return side of the system so you are talking about a lot of really great filtration on this house Miguel amazing house great job on the design I'll put a link in the description to Miguel to the architects the Builder all this equipment this is not a sponsored video so none of these guys are paying us to make this video so I'll put a link to this description but what you're seeing here is a really good system for a really not very big house but we're talking about equipment that's gonna provide comfortable fresh filtered measured air it was installed really well and trust me it's worth the extra money to spend it early on on a good system that's designed and installed well with good equipment guys if you're not a build show subscriber hit that subscribe button below we've got new content every Tuesday and every Friday folsome Twitter Instagram otherwise we'll see you next time on the build show [Music]

Channel: Matt Risinger

Views: 417,276

Keywords: The Build Show, Matt Risinger, Risinger, HVAC, Remodeling, Architecture, Insulation, Passive House, Home, House, Construction, Building, Building Science, Forgecraft Architecture, IQAir, Ultra-Aire, Mitsubishi, Mitsubishi HVAC, Positive Energy, Rockwool, Dorken, Huber, Prosoco, Viewrail, Polywall, Attic, Attic HVAC, Air Conditioning, Passive House HVAC

Id: 8f6Ih09uaDw

Length: 18min 52sec (1132 seconds)

Published: Fri Jul 05 2019