Anyone have experience with Airtight homes?

[bignateyk]

Yeah, my buddy has the tools since he did his himself, wasn't too hard. How is the performance on yours feeding 4 units?

I haven't been through a heating season yet since I installed it in PA. Cooling has been no issue for it, even on the 95+ degree days in a 3500sq ft house.

I still have my electric baseboard units as auxiliary heating in case it can't keep up in the depths of winter.

I went with the ductless heat pump over a traditional ducted heat pump because I could do the install myself easily. Our house doesn't have any ductwork, and the quotes to run ductwork were over $15K.

 

[Kaido]

Why not just make a monolithic dome?

My neighbor's garage is actually a dome, it's pretty cool. I prefer Deltec though: (round house vs. dome home)

http://www.deltechomes.com/

A guy down the street has one, it's amazing! I love open-concept designs and it has amazing views. However, it's not quite the design I want as far as the layout goes. Plus I don't have a huge square footage requirement, so a box makes more sense for how I want things laid out. But I don't think there's anything better than a Deltec on the market right now as far as semi-prefab goes!

 

[Kaido]

I haven't been through a heating season yet since I installed it in PA. Cooling has been no issue for it, even on the 95+ degree days in a 3500sq ft house.

I still have my electric baseboard units as auxiliary heating in case it can't keep up in the depths of winter.

I went with the ductless heat pump over a traditional ducted heat pump because I could do the install myself easily. Our house doesn't have any ductwork, and the quotes to run ductwork were over $15K.

Yeah, plus you're just paying to heat ductwork, which has never made sense to me. Or having to heat the whole house instead of just the specific rooms you are using, since we have the technology to affordably allow individual room temperature control. And select Mitsubishi models have the H2i feature that pulls in hot air from cold temps down to -13F:

http://www.mehvac.com/UploadedFiles/Resource/H2i_brochure.pdf

Introducing Hyper-Heating INVERTER (H2i™) technology*, exclusively from
Mitsubishi Electric and available in select Mr. Slim® Split-ductless and CITY MULTI®
VRFZ models. The cooling and heating success of our INVERTER heat pump systems
is well documented. But we didn’t stop there. We decided to redefine the heat pump
even more.

Imagine sitting toasty warm inside while it’s -13˚ F outside or realizing full heating
capacity at 5˚ F outdoor ambient. Now open your eyes and see the H2i outdoor units. H2i delivers heat, and lots of it.

I'll have to ask my buddy how his worked over the winter, but I don't recall hearing any complaints. I think I'd go with a combination of a log fireplace in one room and a gas fireplace in another for backup heating duties, that way there's some failover if the power goes out as well.

 

[Kaido]

Yeah I wouldn't spend much money on a custom starter home. The only thing's that add value to a house are the ones that have visual appeal, especially to first time buyers who might be buying your home someday.

And that's the thing. Might as well build a full home if I'm going to invest that kind of time & money. I really hate the layout of New England homes - poor layouts, tight stairs, basements, second stories, I just don't like any of that. I like simple, one-floor, open layouts, so if I do get the opportunity to build, I don't really want to move again haha. I also worked for a contractor for a long time and saw firsthand all of the stupid stuff that goes into legacy housebuilding, so I have a pretty big notebook of no no's & things to do differently. But again, I don't have any complex requirements, I just have to figure out where I want to settle down. And then find a large pile of money :biggrin:

 

[Imp]

Been a while... Airtight homes + bad air quality and/or off-gassing home products = building sickness or something something. You can overdo it in trying to save energy.

 

[vi edit]

Yes they are, and I detest them. I hate stairs and hate dealing with a leaky basement. And I know 2-story homes are more efficient for heating in the winter, but eh. I'd rather build it how I want and go from there. But yeah, you have a good point - so I'd have to decide on a starter house vs. a full house, depending on the job, depending on the location. Too many variables, so just in the research phase for right now :biggrin:

Can I just live in an RV instead?

Did you happen to follow my "build thread" from a few years ago?

You don't have to go ultra chic and high tech to get good efficiency. I've got a large house...it's approaching 5000 conditioned sq/ft (counting basement) and in the wildly dramatic summer/winters of the midwest it's very efficient. The highest heating & electric bill I ever had in one of the coldest winters on record was $260(week or more at -10 or more). Last summer had the 2nd highest july on record (something like 20 days over 90 degrees) and my highest bill was about $250.

I'm doing that with basic 2x6 framing, XPS foam, attention to sealing up cracks, basic bat insulation and a small bit of spray foam along floor joists and rafters.

I've got no geothermal, no ultra high efficiency HVAC (zoning, programming ect).

If I lobbed off the 2nd story of my house my bills would be very reasonable. You don't have to overthink this.

 

[RossMAN]

I just have to figure out where I want to settle down. And then find a large pile of money :biggrin:

PM me the GPS coordinates to said "large pile of money" when you find it, thanks :whiste:

 

[Bacstar]

Just moved into a home this summer that has a 5-star energy efficiency rating. Curious to see what my energy usage will be this winter. I have the paperwork of the testing...

Envelope Efficiency

Floor Insulation R-27.2
Wall/Door Insulation R-41.4
Ceiling Insulation 4-42.7
Window R Value R-3.33
Window to Wall Ratio 4.3%
South Facing Window Area 54 ft2
Air Leakage 6.0 Air Changes per hour @ 50 pascals; 0.39 Air changes per hour Natural

Some additional notes on furnace and water heater, and estimated annual energy costs.

Notes: Unit requires 41CFM continuous exhaust Ventilation. Fan with dehimidistat tested @ 59 CFM.

My test results:

1. Airflow @ 50 Pascals (50Pa = 0.2 w.c.): 1384 cfm (+/-0.3%)
2. Leakage Areas: 164.1 in2 (+/- 1.4%) Canadian EqLA @ 10Pa; 94.4 in2 (+/- 2.3%) LBA ELA@ 4Pa
3. Minneapolis Leakage Ratio: 0.34 CFM50 per ft2 surface area
4. Building Leakage Curve: Flow Coefficient (C) = 152.4 (+/- 3.7%)
5. Test Settings: Test Standard = CGSB; Test Mode = Depressurization; Equipment = Model 3 Minneapolis Blower Door

Infiltration Estimates:

1. Estimated Average Annual Infiltration Rate: 149.3 CFM; 0.68 ACH; 49.8 CFM per person
2. Estimated Design Infiltration Rate: Winter 116.3 CFM; 0.53 ACH Summer 61.3 CFM; 0.28ACH
3. Recommended Whole Building Mechanical Ventilation Rate: (based on ASHRAE 62.2) 0.0 CFM

 

[tortillasoup]

I think you're missing the point. The point is, the more airtight a home is, the worse the indoor air quality becomes without some method of ventilation. In extremely insulated homes, most recommendations are to use a mechanical air system (HRV/ERV). In SIP & concrete-based homes, the insulation is very high, which is why this is recommended. Since I'm not a fan of that idea, I'm looking for alternatives that don't rely on an active system (i.e. electricity coming in & a mechanical fan system spinning) and instead can use a more traditional passive system (i.e. window leak).

Air quality is poor in any house that has been built in the last 50 years if you don't open the windows. Actually I'd say most poor air quality is due to the bad building materials like the drywall with formaldehyde in it, etc. Your concern about mechanical ventilation breaking or not working in a small window of time w/o electricity is completely ludicrous. If the power goes out, crack a window open and let in fresh air, rest of the time rely on the HRV/ERV system. PERIOD.

 

[Kaido]

Air quality is poor in any house that has been built in the last 50 years if you don't open the windows. Actually I'd say most poor air quality is due to the bad building materials like the drywall with formaldehyde in it, etc. Your concern about mechanical ventilation breaking or not working in a small window of time w/o electricity is completely ludicrous. If the power goes out, crack a window open and let in fresh air, rest of the time rely on the HRV/ERV system. PERIOD.

You seem very intent on ignoring the science (i.e. the actual issues related to having a more highly-insulated home) and trying to put this issue to rest, without actually exploring the problem and the solutions. Are you an experienced home builder or an air quality inspector, or are you just speaking out of emotion? You seem pretty set on never talking about this issue again. I'm not quite sure why you're not open to discussion, but here is some reading material to get you started:

http://www.murus.com/faqs#What can be done to insure healthy indoor air quality of a SIP structure?

What can be done to insure healthy indoor air quality of a SIP structure?

Indoor air quality has become a major health concern in homes and buildings that are built to meet or exceed today’s energy efficiency mandates. A structure that is properly built with SIPs can be very airtight, so most manufacturers, including Murus, require the inclusion of a mechanical ventilation system in the HVAC plan. Typically this is achieved through the use of a Heat Recovery Ventilator (HRV) or an Energy Recovery Ventilator (ERV). Most of the major HVAC system manufacturers now offer these units as do

http://www.epa.gov/iaq/ia-intro.html

http://www.epa.gov/iaq/

http://greencomplianceplus.markengl...ew-ventilation-systems-todays-airtight-homes/

And it may be a minor concern, since we have electricity nearly 24/7/365 to keep the fan going, but it's still a concern to me because I don't really like the idea of relying on an active mechanical system to handle airflow vs. a passive system that doesn't require any special equipment if the power goes out. Plus the mini-split ductless system I'm interested in does not have a fresh air exchanger built into it. So since most SIP/ICF manufacturers either require or highly recommend a fresh air system, I'm inclined to take their suggestions seriously and do due diligence in my research.

 

[Kaido]

Did you happen to follow my "build thread" from a few years ago?

You don't have to go ultra chic and high tech to get good efficiency. I've got a large house...it's approaching 5000 conditioned sq/ft (counting basement) and in the wildly dramatic summer/winters of the midwest it's very efficient. The highest heating & electric bill I ever had in one of the coldest winters on record was $260(week or more at -10 or more). Last summer had the 2nd highest july on record (something like 20 days over 90 degrees) and my highest bill was about $250.

I'm doing that with basic 2x6 framing, XPS foam, attention to sealing up cracks, basic bat insulation and a small bit of spray foam along floor joists and rafters.

I've got no geothermal, no ultra high efficiency HVAC (zoning, programming ect).

If I lobbed off the 2nd story of my house my bills would be very reasonable. You don't have to overthink this.

Is this it?

http://forums.anandtech.com/showthread.php?t=2056984

Yeah, I'm not so much interested in high efficiency as much as low maintenance. Concrete walls & floors sound great to me, plus I really like the Mr. Slim method of HVAC. Energy efficiency is just a bonus! :awe:

 

[Kaido]

Just moved into a home this summer that has a 5-star energy efficiency rating. Curious to see what my energy usage will be this winter. I have the paperwork of the testing...

Wow nice, I've never seen that kind of data provided with a home before, very cool! How have your summers been so far, pretty reasonable?

 

[Kaido]

PM me the GPS coordinates to said "large pile of money" when you find it, thanks :whiste:

37.892809°N 85.974709°W :awe:

 

[sdifox]

Wow nice, I've never seen that kind of data provided with a home before, very cool! How have your summers been so far, pretty reasonable?

go LEED or go home :awe:

 

[Kaido]

go LEED or go home :awe:

Hah right?

So I talked to my buddy about his Mr. Slim units. They do not act as fresh air exchangers, so you still need an EV/HRV/ERV system in a super-tight house. They do, however, do pretty good at handling humidity, and also have a Dry mode, so that's something. He said they did great in the wintertime (early 1940's home no less) and he didn't have an issue with needing more heat when it got super cold because he got the models with the H2i system, so that's good to hear. The hassle with an air exchange system is having to put in ductwork when you're using per-room units instead of a single central system, so that would be something I'd have to figure out.

 

[sdifox]

Hah right?

So I talked to my buddy about his Mr. Slim units. They do not act as fresh air exchangers, so you still need an EV/HRV/ERV system in a super-tight house. They do, however, do pretty good at handling humidity, and also have a Dry mode, so that's something. He said they did great in the wintertime (early 1940's home no less) and he didn't have an issue with needing more heat when it got super cold because he got the models with the H2i system, so that's good to hear. The hassle with an air exchange system is having to put in ductwork when you're using per-room units instead of a single central system, so that would be something I'd have to figure out.

err, why would you have per room ventilation?

 

[Imp]

go LEED or go home :awe:

Go LEED-ish for ideas, just don't certify it LEED.

 

[Kaido]

err, why would you have per room ventilation?

I don't know enough about tight home ventilation to answer that - do builders only put them in main rooms, not in bedrooms or other closed-off rooms?

 

[tortillasoup]

You seem very intent on ignoring the science (i.e. the actual issues related to having a more highly-insulated home) and trying to put this issue to rest, without actually exploring the problem and the solutions. Are you an experienced home builder or an air quality inspector, or are you just speaking out of emotion? You seem pretty set on never talking about this issue again. I'm not quite sure why you're not open to discussion, but here is some reading material to get you started:

http://www.murus.com/faqs#What can be done to insure healthy indoor air quality of a SIP structure?

Air quality has always been a concern for those who are sensitive to that sort of thing, if they have pets, or other "special needs". It's only just being addressed recently due to the influx of houses that use synthetic materials that are off gassing hazardous chemicals. These articles in regards to air quality give the impression that only in the last decade has this been a problem but really this has been a problem that has steadily been growing for several decades. Builders have only become aware of these air quality concerns due to the extensive use of exotic building science with various high tech chemicals and processes. Notice how they mention SIPs and whatnot, those are fabricated with various chemicals that release VOCs that pollute the interior air. Just think about when you buy a new car, the same concern applies.

http://www.epa.gov/iaq/ia-intro.html

http://www.epa.gov/iaq/

http://greencomplianceplus.markengl...ew-ventilation-systems-todays-airtight-homes/

And it may be a minor concern, since we have electricity nearly 24/7/365 to keep the fan going, but it's still a concern to me because I don't really like the idea of relying on an active mechanical system to handle airflow vs. a passive system that doesn't require any special equipment if the power goes out. Plus the mini-split ductless system I'm interested in does not have a fresh air exchanger built into it. So since most SIP/ICF manufacturers either require or highly recommend a fresh air system, I'm inclined to take their suggestions seriously and do due diligence in my research.

Like I said, most central ventilation systems don't have fresh air intakes anyway so the concern that the mini/split doesn't have it seems sort of moot. I understand your concern about air quality but I thought it's a pretty simple solution to the problem of air quality when the power is out. Crack the windows open all around the house for a little time and you'll have plenty of ventilation. The building envelop of a poorly built that lets fresh air into is is no substitute whatsoever for a direct fresh air intake either through machines, doors, or windows. I'm sure you've gotten the impression from those articles that it IS a substitute but it's certainly not!!! I think you've misunderstood the author's intent in writing the article. The author obviously didn't want to shame SIPs but wanted to point out that you need fresh air ventilation in a house. Instead you've drawn the conclusion that you need to make a house with a poor envelop so that "fresh air" can sneak into the cracks which is just ridiculous.

FYI I live in a house built in 1972 with hardly any insulation and a poor building envelope and I still find my self opening the windows and getting fresh air ventilation because otherwise the air gets stale inside and just doesn't smell right. Not going to start poking holes in the dry wall to "let in the fresh air"...

 

[jaedaliu]

I don't know enough about tight home ventilation to answer that - do builders only put them in main rooms, not in bedrooms or other closed-off rooms?

internal doors typically don't seal out air.

So you probably only need 3.

1) your main house

2) panic room

3) sex dungeon. Make sure you have good sound proofing for this one, you don't want your wife to wake up in the middle of the night and investigate the noise.

 

[Kaido]

internal doors typically don't seal out air.

So you probably only need 3.

Not sure if it would make a difference, but the indoor doors would probably be fiberglass or some other non-wood composite. Don't want any wood in this house. Concrete walls & metal cabinets, yeah baby! :awe:

 

[mizzou]

I'm not going to read all the comments, but you don't want a perfectly airtight house.

 

[Kaido]

I'm not going to read all the comments, but you don't want a perfectly airtight house.

True, plus it's pretty much impossible to do. Even the concrete & SIP homes still have air leakage, it's just that there is less leakage in a more tightly-designed home, thus they get the recommendation to have an outside airflow system installed.

 

[vi edit]

We all have our quirks and ideals, but all I can say is God help you should you need to sell. Very, very few people want a sterile bunker to live in.

 

[Kaido]

We all have our quirks and ideals, but all I can say is God help you should you need to sell. Very, very few people want a sterile bunker to live in.

Aye, and that would be the hassle. However, the sterile bunker visualization only applies during the building phase. Once carpeting & tile gets put in, interior & exterior stone veneer & paint go up, ceiling tiles get put in, etc., it looks like any other normal house.

Except for the zombie defense system. But that's extra