Re-post. AC units and Split System Heat Pumps

I get a lot of questions about cooling a home and HVAC in general. We specify air-to-air heat pumps on most of our jobs these days. They are similar to 'geothermal' which is air-to-water or air-to-ground heat pump technology, except you don't have to dig a hole in the ground.

We find the air-to-air heat pumps (also called 'splits or 'minisplits'), more efficient, much less expensive and less temperamental to install.  People still say 'what about Geothermal?' Well, we specified our last geothermal systems about 4 years ago and I don't see any reason why would specify one again with these great units on the market!

Here is a great article by Alex Wilson of Environmental Building News that compares cooling options of all types:

Choosing an Air Conditioner

Posted July 11, 2012 11:17 AM by Alex Wilson

Understanding the options with room air conditioners, central air conditioners, and heat pumps.

The outdoor unit of a Daikin mini-split air-sourceheat pump in Putney, Vermont. Click to enlarge.
Photo Credit: Alex Wilson

Question:

I have never owned an air conditioner, and I don’t have any immediate plans to change that. But if I did, what would I look for?

Answer:

For only occasional use and when you don’t want to spend more than $1,000, the options are limited to room air conditioners, which are most commonly installed in windows. These cool the rooms in which they are installed, though in a small house or one that’s very-well-insulated and tight, a single window unit may be able to cool much of the house.

Most room air conditioners are either installed in a double-hung window or in an opening in the wall specially created for the air conditioner. Special models are available that can be used in casement windows, though installation is trickier.

Window air conditioners are usually installed in the late spring or summer and removed in the fall. Because they don’t seal tightly in the window, they should not be left in place during the winter months, as they will result in cold drafts. Room air conditioners that fit into custom openings through the wall may be left in place as long as they are fairly well-sealing (most are not), and if they are removed the opening should be carefully sealed for the winter.

For whole-house cooling, central air conditioners or heat pumps are used, and chilled air is distributed through ducts. Heat pumps offer the advantage of being able to provide both cooling and heating—by reversing the refrigerant cycle seasonally. If I were putting in an air conditioning system and my budget allowed, I would install one of the new-generation mini-split air-source heat pumps. (Very significant for those of us in the Northeast, the cost of delivered heat from these heat pumps is usually lower than that of oil.)

Room air conditioner efficiencies and performance

Room air conditioner performance is reported as the Energy Efficiency Rating (EER), which is a measure of the energy output in Btus (British Thermal Units) per hour divided by the energy input in watts, assuming standard conditions (usually 95°F outside temperature and 50% relative humidity).

Federally mandated efficiency requirements for room air conditioners vary depending on size, ranging from an EER of 8.5 for models over 20,000 Btu/hour to 9.8 for models in the 8,000 to 14,000 Btu/hour size. To meet the Energy Star standard in these size categories, the EER must be a minimum of 9.4 and 10.8, respectively. The thresholds are somewhat more relaxed for the smallest units.

Today’s best room air conditioners have EERs over 11.5, but relatively few exceed 10.8.

SEER ratings for central air conditioners and heat pumps

Central air conditioners and air-source heat pumps in cooling mode are typically rated on a seasonal bases using the seasonal energy efficiency rating (SEER). This is the total seasonal cooling output in Btus divided by the watt-hours of electricity consumption.

Central air conditioners and air-source heat pumps must have SEER ratings of 13.0 or higher. On January 1, 2015, those standards are scheduled to be tightened. To qualify for the Energy Starstandard, central air conditioners and air-source heat pumps both must have SEER ratings of 14.5 for split systems (separate indoor and outdoor components) or 14.0 for packaged units.

The best central air conditioners and air-source heat pumps today have SEER ratings above 22.

Moisture removal with air conditioners

All air conditioners remove moisture, as described in last week’s blog. While there are no federal requirements or measurement standards for moisture removal, most manufacturers list moisture removal in pints of water per hour. As a first step, you must properly size an air conditioner to achieve good moisture removal (see below). If humidity is a problem, look for models that are effective at moisture removal. Models with variable-speed motors are typically more effective at moisture removal.

Discuss moisture removal with a dealer or air conditioning contractor. Your particular situation and humidity conditions may inform the product recommendations.

Sizing air conditioners and heat pumps

Particularly with central air conditioners and heat pumps, sizing is key to successful performance. With an oversized unit, frequent on-off cycling will occur, efficiency will drop, and moisture removal will be poor. Sizing requires carrying out detailed cooling load calculations; it is not something that should be done using rules of thumb. The sizing of ducting with a central unit is also very important, both for efficient operation and noise control. 

Making decisions

A knowledgeable air conditioner salesperson should be able to help you pick out a quality room air conditioner. Insist on an Energy Star-listed model, ask about moisture removal, and then consider technical support, warranties, manufacturer reputation, and service in making your buying decision.

With central air conditioners and heat pumps, talk with air conditioning contractors and suppliers, but be aware that specific contractors may push only those products they are most familiar with or manufacturers they represent. The latest mini-split air-source heat pumps from such manufacturers as Mitsubishi, Daikin, Panasonic, and Fujitsu offer—in my opinion—the best option available today.

If the air conditioning contractor you contact doesn’t provide these systems, I would suggest that you seek out other contractors or suppliers before proceeding with a purchase.

The information above and in our GreenSpec guide should help you find the right central air conditioners and heat pumps.

Alex is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. He also coauthored BuildingGreen’s special report on windows that just came out. To keep up with Alex’s latest articles and musings, you can sign up for his Twitter feed.

Posted by Alex Wilson on July 11, 2012

LED Bulbs

Please check out this great article on LED bulbs if you are interested in learning more about saving a lot of money and energy while getting the great light quality of my 'personal bulb favorite" ~ the LED!

http://greenspec.buildinggreen.com/content/beat-bulb-ban-led-replacement-lamps-new-light

At Trillium we have been specifying only LED can lights for 5 years now. They just keep getting better. The light quality is great, they turn on to full light capacity right off the bat and they save a ton of energy. Right now almost every non-decorative light fixture  in my house is an LED. That is about 20 lights and the vast majority of the lighting in the house. Each of those bulbs cost about $1.00 a year in electricity. 

One of the complaints about the bulbs are cost. The most popular/ famous bulb right now is the Philips EnduraLED. These are most of what I have in my house. I have never paid more than $15 for one. There is a comment on the bottom of this article referring to payback times, but that comment quotes the price of the Philips EnduraLED as $25. So cut the payback times in half. The prices are dropping on these bulbs all of the time.  

Also none of our residential projects have had the issues with flickering or dimming problems noted in the article. LEDs do not dim 100%. They dim to anywhere form 80-90%. This is getting remedied as the bulbs evolve but so far does not seem to represent a huge problem to the user.

The one issue I have had to adjust to with these bulbs is that they are brighter than you think they will be. We have had to learn to draw in less lighting points into our electrical lighting plans. For instance, instead of putting 6 cans in a kitchen we may only put 4. This actually is a great money saver! But it is a difference to designers.  YOu have to learn to think in a slightly new way about creating the 'lighting experience' of the home.

Decorative LEDs are also on the rise and the last LEED home we did used many of these to great effect. The light is a very nice soft white. And its a very white-white...not yellowish-white, not bluish-white like many CFLs.

We highly promote the use of LEDs here at Trillium. If you have any questions about them please feel free to call the office!

Kids Make Primitive Shelters

Trillium spent this weekend helping kids learn about primitive shelters. We all had a great time getting dirty with sticks, leaves, earth, pine bows and ground cover. As it turns out, making things stand up is the hardest part! Patience and a basic understanding of physics were the first lessons. Everyone thought they would like to camp out for a nite in their shelter but I think only one kid thought he might want to live there~ sounds about right for the general population! Some of the houses were quite creative and beautiful. Have a look at some of the constructions:

View Full Album

Grey Water Re-Use

(I hope my cousin does not mind but I am posting one of our email correspondances here! Basically Cousin was interested in integrating a grey water re-use system into her home in Pennsylvania)

Her question:

Hi Cousin,  I'm adding a bathroom to my house and asked my architect if i can have something installed to recycle the graywater from the bath/shower. I got a blank look!!!! then was told the local permitting process probably wouldn't permit it. When I was in Israel, my friend Yonit's shower drain led directly to her garden via a piece of exterior pvc pipe  are homes in the Northeast ever designed to recycle graywater? are there resources for my builder/architect to come up to speed on it if so? 

 (my rainbarrel )

My Answer:

I love the idea of grey water re-use and so do my clients BUT my clients usually end up just collecting their rain water and recycling it into watering gardens etc. The reason is simply cost. The more you are using actual grey water (from shower, washer, etc) the more you get into costly plumbing and filter systems and the more maintenance. (There are actually health issues re: bacteria and our codes are likely more stringent than in Israel,etc. That said every county is different- talk to your local water/ health official.  But yes it can be done and is done... sometimes)   

first a couple of links:

http://www.smarterhomes.org.nz/water/re-using-greywater/

http://www.greenbuildingadvisor.com/community/forum/green-products-and-materials/20806/grey-water-filtration-system

All of my clients so far have balked at the cost and opted for simple rain barrels or more elaborate rain water collection systems- gutters drain to underground holding tanks and go through light filtering, and are plumbed to the garden hoses or to an automated garden watering system...with overflow for the whole system to sewer or septic system. One step beyond this would be doing the plumbing to bring it to your toilet etc. This gets into minorly complicated plumbing because you have to be able to get water from your regular source as well as your water collection. Beyond this - potable water- is also possible with enough filters and plumbing. Just gets into $$$.  

 

(Image from Stark Environmental- Thank you Michael.)
Ironically the water collection guy I have talked to the most about water systems is in PA.

Here is his info: Michael Stark,  mstark@starkenvironmental.com, http://www.starkenvironmental.com/b-8-consultation.html  

You may not be able to get into the second link without a password so I copied below. I DO NOT agree with 'Maritn' on this one - his claim - that saving water in places with plenty of water is a waste of time- I feel is in correct. We are all going to be in a water crisis soon enough and what we do actually effects the whole world...for real scientific reasons - not just good karma!

Green Building Advisor Link: 

Grey water filtration system I have a customer requesting the installation of a grey water filtration/recycling system. The customer lives in the DC area and has explained that these systems are common and considered "green" in application in the urban DC area. The home I will be building for the customer is in the rural mountains of West Virginia. There is no shortage of water up here we have received close to 35" this year to date and average about 60" a year. We are looking to make budget decisions on "green" components. I admit I know little about these systems and have not talked to a plumber around here yet that doesn't say it is a waste of money. Is a grey water filtration/recycling system still "green" in an area that sees no water issues or will the system have a bigger footprint in terms of excess materials, maintenance, etc? ASKED BY JOSEPH GARTEN  POSTED SUN, 05/22/2011 - 10:47 

Answers newest to oldest oldest to newest:

You are probably better off using rainwater catchment over gray water. The water is much more pure, it needs minimal filtration and the entire system requires much less maintenance. Health codes generally restrict gray water to use in toilets and underground irrigation, while rainwater can be used for almost any use, including potable water (with proper filtration) and spray irrigation. The cost per gallon for rainwater is significantly less than gray water in terms of both first cost and ongoing maintenance. It may be appropriate to pipe the drains and toilet supplies for gray water even if you don't install the system initially. If higher performance gray water systems become available, then you can always install one, and having separate supply lines to toilets and laundry will allow you to use either rainwater or a future gray water system with minimal extra effort. ANSWERED BY CARL SEVILLE, GBA ADVISOR  Posted Sun, 05/22/2011 - 19:31 2.

Joseph, Good green design and building doesn't follow a cookie-cutter checklist developed for a national audience. I agree with your implied criticism of greywater recycling systems for houses in high-rainfall areas: they don't make a lot of sense. Each climate has its own challenges. Where I live in northern Vermont, for example, water is plentiful, but warm days are few. In this climate, a very good thermal envelope designed to retain heat is an important green feature. Features designed to save water are much less important. Of course, in parts of Arizona or New Mexico, my priorities would be reversed. ANSWERED BY MARTIN HOLLADAY, GBA ADVISOR  Posted Mon, 05/23/2011 - 04:53

Thanks for responses. I was thinking along the same lines Martin. What I am really thinking though...how green can you be if your building an elaborate vacation home in a poor rural community? Things are getting pretty twisted....green washing. ANSWERED BY JOSEPH GARTEN  Posted Sun, 05/29/2011 - 19:31      

Already February!

I can't believe it is mid -February and we have barely had winter this year! 

I think everyone is feeling hopeful in 2012. So far Trillium is off to a bubbling start with lots of new home renovation jobs and a couple of new modern green homes on the boards. 

Remember - just because your realtors tell you modern doesn't sell doesn't mean it's true. I have so many clients who walk in the door and say 'what I really want is a modern home, but my realtor tells me I can't build one.' No! It may not be the biggest market but there truly is a market for houses that are a bit more 'dwell magazine'. And we love to design them! 

We will start posting more images of what we are working on soon...here is one for now~

 

In the mean time Happy non-winter/ almost spring/ new year and happy renovating!

Elizabeth

Building a Hybrid Wall

I am one of the 'Pro's' on the Green Home Guide Website and as so I answer technical questions every month regarding green building. It is a very informative site!

Here is a link: http://greenhomeguide.com/

Below is one of my most recent question/answer's:

Q: New Construction, is a hybrid system the way to go for a 2x6 walls, 1 inch foam and the rest blown cellulose? Hybrid system vs just blown in cellulose for 2x6?

Asked by Scott

Paw Paw, MI

 

Hi Scott

As an Architect who designs only sustainable homes I am always a fan of the hybrid wall. But you have to do it right. You climate will heavily influence the type of hybrid wall you should build.

I see that Paw Paw, MI is in climate zone 5 but the northern edge of climate zone 5.

I live and work at the southern edge of climate zone 5 and a lot of our work falls to climate zone 4 or is right on the edge of 5 and 4. 

Why am I saying all of this? Basically there is a ratio of exterior foam board insulation to interior cavity insulation that is ideal to achieve a great thermal envelope and at the same time avoid issues of moisture and mold occurring within the wall cavity. Basically the warmer the climate zone, the less exterior vs interior insulation you need to avoid air travelling into the wall cavity, reaching the dew point and turning into moisture.

So, in Zone 4 you can easily get away with 1 inch of polyiso rigid board insulation on the outside (about an R5) and 2x6 walls on the inside filled with foam or cellulose or some other cavity insulation. But when you get to Zone 5 you will get into trouble when you do that. In my area (southern Zone 5) you need at least an R7.5 (generally speaking) which is about an inch and a half. As you get more northern you need more- up to 2 or 2 ½ inches of rigid foam to your interior wall cavity.

The ironic thing is that – because this is all about the ratio of exterior to interior- if you build a 2x4 wall you need less exterior insulation. But in the colder climates what is the point of that? If you do that you significantly reduce the overall R value of your wall.

The biggest complication of putting more than 1” of rigid insulation on the exterior turns out to be construction. If you are only using 1” you can shoot your siding right through that to the stud beyond and it really does not complicate the construction process.

However if you are using more than an inch you have to introduce battens on top of the rigid insulation and lag through to the studs beyond and then attach your siding to the battens. (If you are using lap siding this is simple- battens are vertical to allow water to run down the wall, lap siding fastens horizontally across. But if you are using shingles or vertical panels you have to add horizontal nailers on top of the vertical battens and then attach shingles, panels etc. This is called a rain screen. There is more labor and a bit more material cost (battens are cheap).

This is a GREAT wall. Probably the best wall you can get. You get a lot of continuous insulation around the house plus you have an air space (the rainscreen) between you siding and the house itself. This air space makes the siding and the siding’s finish (no matter what kind of siding) last longer and require a lot less maintenance/ painting. If there is enough money in the job I will always go for this wall.

In your northern climate you deserve this wall! Your house will perform really well and you would not be sorry.

Another way to do the wall (my friends in Minnesota do this sort of wall primarily) is to simply build a double wall. Maybe a 2x4 wall, then a 2 “ gap, then another 2x4 wall. Fill the whole thing with whatever insulation you like. Cuts thermal bridging and you avoid the ratio issue.

One big factor of getting your wall to perform well is to focus on air infiltration as well as R Values. Some insulations like spray foams and rigid foam boards have their own innate air barrier properties, whereas batt and loose fill insulations like cellulose, cotton batt, blown fiberglass, etc do not.  If you use one of the latter you should also pay very close attention so sealing all air gaps in the wall assembly. (You should do so with the foams as well, of course. There are simple less gaps in the foamed walls. ) That is a whole other topic.

In summing up- hybrid walls are great, you just have to do them right. There is a lot of information and complexity to true building science. You can usually get more help form one of your local green building professional to talk through your exact project. Just make sure whomever you talk to really knows their stuff and didn’t just recently become ‘green’ for marketing reasons!

Best of luck!

Elizabeth DiSalvo, Architect

To Window or Not To Window?

To Window or Not to Window?

Below is my response to a post by Martin Holliday on the Green Building Advisor Web Site.  See article here:

http://www.greenbuildingadvisor.com/blogs/dept/musings/more-energy-myths#comment-34970

Basically part of the article states that it is really not worth it financially to get new windows because though they do save energy, you will not get 'pay back' for those windows during the life time of those windows. Something we hear regularly enough in the green building world. The recommendation is to basically just buy storm windows instead.

MY RESPONSE:

I understand every point that Martin is making about windows- I have heard it many times- but there are a few points that engineers never (rarely) take into account in the window replacement argument. (And I get that this is the engineer's job- cold hard data- and 'get a storm window' is the answer when you are just looking at the cold hard data of energy saving vs cost of new windows - both monetarily and in embodied energy. So fine- I get it.) 

BUT, I am an architect and I am very pro 'window replacement' for the following reasons:

1. Good windows DO save energy and money. (Ok you don't get to full payback on energy alone.)

2. Good windows give you the actual feeling of comfort in a house- better than a storm does (believe me I live with both right this second.) You do not have the experience of sitting next to a very cold surface with a good new window.

3. Safety. Most old windows barely open. Add a stiff, hard to operate storm window (and we all know they are that way) and you double the problem. I changed the windows in the house I live in when my 7 year old was afraid of fire and kept asking me 'but how mommy- how can we open the windows and get out?' I looked at our crappy single pane double-hungs with their impossible storms (that, btw, no fireman could fit thru),  and I put an ax next to my son's bedroom window and ordered new windows. Neither my son nor my 72 year old mother could open any windows in the house more than a crack when the storms are on in the winter, I can only  open them a bit more than they can. We don't have the strength. There are THOUSANDS of houses like this in the U.S.

4. Aesthetics. Want to up the value of your house? Want to get some curb appeal? Try new windows. Yes some historic homes look way better with their original windows but most houses built between 1940 and 1990 would be greatly enhanced with decent windows. This may seem like a minor point to some but - hey - your house is your biggest investment. Re-sale is usually important. Windows often 'make' the house. 

5. Leakage; Leakage DOES matter. Even if it is not as much as your attic or basement (Note also that one of the things on the recommendation list (above) is to have a blower door test and another is to insulate the attic ONLY AFTER sealing the ceiling below the attic - so it MUST matter right?)  When you replace your windows you actually have a chance to do it right, kill much of the air infiltration and also stave off, or mitigate a lot of moisture rot. We all know that basically every house from the 50's and 60's with single pane windows is rotting at the sills as we speak - if they have not already been cobbled with trim, flashing and caulk 'band-aids' many times already.

Anyway- I know the point Martin is making about windows is valid- sort of- but I am so tired of the green industry telling everyone to not waste their money on new windows!! These 5 other reasons are very strong reasons to get new windows and I think we should all be taking a more integrated, whole house approach to our buildings. And speaking more carefully about getting new windows. 

Also - curtains in the windows may not really help- by the numbers- for keeping your house warmer/ saving energy- BUT they sure do make you feel better in a room with those cold windows in the

winter....

Elizabeth

In the News!

 

Our latest LEED Registered home was featured in the Darien News last week! We were happy to spread the word about living alternatively in Fairfield County. More and more people of wealth are considering a simpler life style with a smaller carbon footprint. You can read here about a family who chose to build a smaller home and to make it as clean and green as they possibly could! We love the story behind this house and the process was such a great experience for everyone involved that we hold it up as the model for what we think every home building experience should replicate. 

Here is the link:

/darien-news-9-30-11/

Enjoy!

Elizabeth

Farmer's Market!

We had a great time at the Westport Farmer's Market today! The Westport Market is perhaps the most established and respected markets in Fairfield County. Amazing produce! Delicious food! Interesting and purposeful people. 

We spent four hours talking to visitors about prioritizing their green home renovations. So much fun to talk to such an educated and conscientious group. People of such conviction and compassion are truly our very best clients! We encourage everyone we spoke with to give us a call when you are ready to do some renovating! We would love to work with you!

We will be at the market once a month next summer and will likely appear at the Winter Market too. Look for us there and please stop by and say hi!

http://westportfarmersmarket.com/

This Weekend ~ SoNo Arts Fest!

As happens every year Trillium Architects will be at the SoNo Arts Festival Aug 6 and 7, 10-5. Please come on by for free architecture advise and newly added sat. afternoon cocktail hour featuring free Dark and Stormies! 3-5! Come on by!

 

http://sonoarts.org/

April 11, 2010 ~ Should I really build a well sealed home??

I like this article form Fine Home Building- it explains the 'tight house'. 

Like I have said before- it's like a swimming pool- you don't want cracks and leaks all over the place- you will just keep having to fill the pool with more water! You want to be in full control of the amount of water in your pool and its temperature. Same goes for your house. You want to be in control of when and where air (and moisture) comes in and goes out and its temperature. If you have a leaky house, you are not in control. Leaks cause problems whether they are air or water leaks.

Please read this article for more info! Download FHB- The Well Sealed Home

30 November 2010 ~ A Great Blower Door Test!

Congratulations to B P C Green Builders + Trillium Architects!

Yes we are patting ourselves on the back. Yesterday we did the blower door test for the house in Rowayton. For those of you who don't know what a blower door test is you can read about it here. Basically it is a test to see how air tight and generally awesomely well constructed for energy efficiency a house is.

The lower the number the better. As a reference:

The
IRC’s current energy code requires 7 ACH at 50 pascals.

Energy Star requires less than 5 or 6 ACH, depending on the climate zone.

Tight house Less than 5 ACH/50
Moderate house Between5 and10 ACH/50
A Leaky house Above 10 ACH/50

The Rowayton House (drum roll please.....) 1.2 ACH/50 !!!!

This test  just how awesome a job the contractor did at building the house. The truth is hidden in the walls and once the drywall is on the inside and the siding is on the outside you have few ways of knowing what is really happening within the walls. And if you are not on site all day everyday watching the contractors work, you could miss a lot. An architect's best friend is a trustworthy contractor. A trustworthy contractor is - of course- also the owner's best friend.

They are hard to come by but they definitely exist. BPC Green Builders (Chris and Mike Trolle) are definitely a great example.

Every construction project takes a team. The owner has a dream, the architect draws the dream and the builders constructs the dream. Along the way there is a ton of planning, changing, detailing, thinking ahead, worrying and bill paying. We all discuss and work on detailing the house and figure out exactly how it will be built. But a lot of times no matter how much you figure it out ahead of time or how well the architect details a house...it doesn't always get built the way it was planned.A bad contractor cuts corners when architect and owner aren't looking. A good contractor builds it better than the architect and owner expect.

I just want to publicly thanks Chris Trolle for a job VERY well done. Every job meeting was -if not simply very pleasant - actually fun. The entire construction project was a smooth sailing. And the results are undeniable.

I also want to thank Leslie for being an awesome client. They don't come any better: Smart, savvy, good at communication, completely understanding of the process and great at allowing the process to happen, plus a fabulous eye for design and wonderful taste. A true and equal team player. 

02 November 2010 ~ A Video Of Rowayton House

28 October 2010 ~ Catching up

For a while now things have been too busy to write. 3 of our 4 houses are now basically complete. The third family moves into the third house tomorrow. This is the house in Rowayton- the LEED certified house. We will be wrapping things up and doing final testings and then we will see where it stands- LEED gold or LEED platinum. Meanwhile   broken ground on what will be our second LEED home in Darien. It is interesting how different the process is with this one. I will be blogging regularly about as we proceed.

One final note as the day ends- we will be holding free classes in our office revolving around 'How to prioritize your energy efficient, green renovation or new home' and 'How to work with an architect or contractor.' Please check back for dates!

May 29, 2010 ~ House Parts: Insulation

OK, let's talk insulation.

The number one basic rule in creating an energy efficient building is 'first address the envelope'.

What does that mean? Well, when we say envelope we mean the outer shell of the house. The roof, all of the exterior walls. the bottom floor/ slab/ basement/ crawlspace (whichever the case may be.) So the first goal is to make that envelope a) very well insulated b) very well sealed by filling any holes, penetrations, nooks and crannies and cracks  c) protected from moisture infiltration and d) protected from air infiltration.

A lot of people's reaction to this is 'I don't want to live in a sealed box!' or 'Isn't it bad or dangerous to completely seal your house??' while it is true that a house needs to be sealed with care and that concerns about air exchange need to be addressed, you actually do want a well sealed home. AND just to ease your mind- addressing the air exchange in a well sealed house goes hand in hand with sealing the house. It is a given- like breathing- no architect or builder who builds well built, well insulated, well sealed houses will ever 'forget' to provide fresh air (unless they are a completely crazy or utterly incompetent and you will have noticed that long before you get to the building sealing stage! ) 

Basically I always use my swimming pool analogy. If you own a  swimming pool, you want to be in control of when the water leaves or enters your pool. If your pool was full of little cracks you would have no control over the water. You would have to continually fill the pool and constantly adjust and observe water levels, and all sorts of problems would occur in the area of the cracks (the cracks get bigger, deterioration of the liner occurs faster, dirt and critters collect there,etc, etc.) You want the same for your house. YOU want to control when and where air and moisture come and go. Simple. Logical.

Ok - back to the rules of the envelope list:  a) very well insulated b) very well sealed by filling any holes, penetrations, nooks and crannies and cracks  c) protected from moisture infiltration and d) protected from air infiltration.

The last 3 have to do with preventing the flow of air and moisture through the walls and are addressed through caulking and flashing and various tapes and sheet barriers (think Tyvek- tho we don't use Tyvek exactly). The reason you want to keep moisture and air from flowing back and forth through your walls is that air and moisture are the very things that cause building material deterioration, mold and mildew and dust (major allaergens), dust mites (which lead to spiders), insects and critters, etc. All are bad! bad! bad! for a house! never mind you the occupant. Remember the laws of physics: hot moves toward cold, wet moves toward dry. Air constantly wants to move through your walls and moisture travels on the air. We want to keep air and moisture from traveling through the walls. We want to control where and when it goes in and out ot the house and we will do it though ducts and vents and other specifically planned appetures. (AND we will talk more about how to do that in another post.)

One other thing that the flow of air and moisture do is that they reduce the functional R-value of your insulation.

SO now lets focus on the first item on the list - the insulation.

There are many types of insulation and they are all rated by one rating system and labeled with something called an R-Value. R-Value is a measure of thermal Resistance. The higher the R-value the better the insulation is at keeping heat or cool  inside your house at a steady temperature - this is because it is better at not allowing the heat to pass through it (either going out or coming in)...thus the term thermal resistance.

Most houses that were built in the post war era used fiberglass batt insulation (the pink stuff, the stuff you don't want to touch or breathe, the pink pather stuff, the stuff as one insulator I know says 'works GREAT as a filter! Cause the air passes right through it! which makes it not so awesome at thermal resistance' ) Usually we find houses of this era built with 2x4 studs so that means there is fiberglass batt insulation- about 3.5" thick slumping in the walls. Unless fiberglass batt is meticulously installed and unless it never aged and pulled itself off its staples overtime - its not really filling the wall cavity. Bottom line- its not the best insulator, it needs to be really well installed and almost never is, it falls and gets dirty over time, its bad for you to work with, critters don't mind it. We never specify it. We can't even believe people still use it as their primary insulation.

So what are the options. Well in the old days people used all sorts of things from straw to newspaper, to mud, tires, almost anything has been packed into walls. But we want something easily available, verifiably tested, regulated, readily installed, fire resistant, critter resistant, clean, mold and mildew free, etc. If we are going to make a good, well sealed, clean and healthy house we want insulations that work and work with our newer building methods.

The options we look at fall into these categories:

Blow in foams (Open cell or Closed Cell)

blow in 'other' (cellulose, fiberglass, cotton)

Batts (cotton or other)

Rigid Foam Boards (XPS, EPS, Polyiso)

17 May 2010 ~ House Parts - Siding

Here are some updated photos of the Rowayton House. It is getting its siding put on and Carlos and his team are doing a great job!  

The siding is James Hardie Hardie Board - a fiber cement composite product. The trim is MiraTEC  which "are manufactured with environmentally preferable phenolic resins use recycled content and have no added formaldehyde". We are using these products because they greatly reduce the need for maintenance (including painting and cleaning with harsh chemicals) and last a very long time (both can easily go 20 years without a new paint job and will last indefinitely.)And by using these products we are not using raw natural recourses- like Cedar,etc. Plus these products look great. We are VERY picky regarding aesthetics and these pass the test.

 
 

We do not use vinyl products on any of our houses (unless ABSOLUTELY necessary for very small applications where nothing else will hold up to the weather). We do not use vinyl becuase it has such a negative impact on the environment and the people who live inthe vicinity of vinly plants (cancer, mostly in the soth). Please check out the film Blue Vinyl for a better understanding. plus vinyl looks awful and is NOT problem free...

What are all of those battens doing there? You can see vertical wood battens all over the house. These are for letting the siding 'breathe'. Allowing the siding to breathe reduces moisture build up behind the siding and makes the siding and the paint job last even LONGER! (This also works with cedar or any other siding.)

We have clad the house with a structural insulated sheathing (SIS) material from Dow (a 1" thick board that replaces normal sheathing- like plywood or OBS) that does the double job of giving stability to the framing and a continous layer of insulation for a much better thermal envelope (more on that in the Insulation Post which is coming I promise! I have been so busy and that post will be a meaty one!) Anyway the SIS also has the added benifit of providing an air barrier- sort of like Tyvek. We have taped all of the seams at the edges of each board and at each door and window,etc. Reducing the amount of air infiltrating into the house does the same thing that the airspace behind the shingles does- it tremendously reduces the amount of moisture and deterioration  within the wall. And that cuts down on mold, mildew, dust mites and spiders,etc. never mind rot! AND it makes the insulation perform much better.

Air moves moisture. Hot (air) moves toward cold, moist moves towards dry (usually via the air). Basic thermodynamics. We want moisute to stay out of walls and away from siding or anything else that likes to be eaten by mold and mildew. We want to control temperature and moisture.

I always say: Its like a swimming pool. You don't want any cracks in your swimming pool. If you have cracks and you want your pool to be full- it will seep out thru the bottom. If you have cracks and you want your pool to be empty you will have water seeping in from underground. You want to control when water goes in and when it goes out. (You can't control it all- think splashing or evaporation.) But you can do you best to control it where you can. Then YOU decide when to add or subtract water.

Your house is the same. Your walls are the same. YOU can control the air and moisture in your home (or you equipment can do so automatically. You can either have a passive or active system monitor your air and moisture.) But you know exactly how, when and where it is coming and going. This also allows for installing air filtration systems. A tight, well sealed, well insulated house is never lacking for fresh air if done correctly. Simple air exchange- fans,etc. easily assure the homeowner of pleanty of fresh air... More on that in the Insulation part also.

OK- have a great day! More soon!

Elizabeth

04 May 2010 ~ A 'rant' from Justin the conscientious realator...

GUEST BLOGGER!

(But remember ~ Justin is in Colorado- things are a bit different here in the North East…but not much…)

Hybridize Your Home!

‘Hybridize Your Home’ is a term that I like to use to describe the path to alternative energy because it seems like so many think that energy efficiency is still the realm of granola-eating hippies at the one end, and the changing of a few light bulbs at the other.  Hybridized makes us think of smart neighbors that drive a Prius and have Scandinavian designed computer bags.  Also, hybridization implies multiple systems functioning simultaneously, or trading off when it is better for one to work than the other.  Which is perfect for describing how we can improve the value, livability, and carbon footprint of our homes.

I raise hybridization and alternative energy with you as your Realtor because it is fundamentally tied to the cost of your home, and the long-term enjoyment and comfort of that home.  (As always, email me at justinchipman@kw.com or give me a call at 303-955-4618 for specific information about your home, or to schedule a free consultation).  

Because it is beyond the scope of an email, let me give you ten quick ideas to think about alternative energy and the direction that you need to take to maximize the use of your dollars, and to minimize the cost of living and the energy that you use.

As a general rule, lower your consumption through efficiency and smart choices, then look to the sun.  Here are some important steps.

1.  Look at your energy bill!  Most people just see the shocking number at the bottom, but you need to look at the breakdown between gas (or oil) and electricity.  Chances are that, if you are in Colorado, you spend vastly more on gas (North East = Oil) than you do on electricity.  Also, it is important to remember that the energy company is a privately owned, for-profit business.  By law they seek to maximize their profits, which means they want for you to spend as much as you can.  See them as a direct competitor for your money, so they are not a reliable source when you have questions about how to minimize your energy needs.

2.  After you determine which is greater, consider that you will get more bang for your buck by first focusing on more efficient gas systems than on replacing your electrical system.  It looks really good to get that big rack of panels on your rooftop—and I encourage that--but it is always cheaper and easier to go for the other things first.  Let the savings from a tank-less system pay for those panels in a few years.

3.  ‘Go Tank-less’.  Tank-less hot water systems have come a long way.  They are expensive if compared to the up front cost of a conventional hot water unit, but that difference is paid off quickly.  It costs more to keep a conventional hot water heater hot than it does for one person to actually use a tank-less system.  Think about how really stupid it is for us, as a nation, to be keeping 4.8 billion gallons of water hot all of the time.

That’s right, about 4.8 billion gallons of water are being kept hot right now.  We could save that energy every second of every day just by going tank-less.

4.  Replace when things break.  Most of us have old hot water heaters and forced air heating systems.  If you have a furnace that needs new guts, or a hot water heater that has rotted from inside out, then now is the time to go tank-less.  Tank-less systems can REPLACE your furnace AND provide you with hot water.  The savings are massive (can be about 50%).  These systems seem expensive up front, but remember the cost to our society—4.8 billion gallons being kept hot every second of every day.  The cost of the replacement is actually trivial by comparison.

Remember, the energy companies are your enemy in this.  4.8 billion gallons of sitting hot water is nice payday for them, so the nation by being sensibly alternative costs the private energy companies Trillions.  Oh, that is not a loss unless you watch Fox.  Those trillions saved by you can be used to spend on other things that you might want more.  Things like sending your kids to college.  A new car.  A nicer home.  You get the idea.

5.  Solar Thermal Supplement.  (SOLAR DOES WORK IN THE NORTHEAST! Not as well as it does in Colorado, but it does work). Solar thermal panels can quickly heat water to near boiling temperatures, so much of the time this can provide you with your domestic hot water needs (if you can adjust when you shower and do the dishes, solar thermal systems can easily replace the need for any other hot water system.)  The panels are also relatively inexpensive.  The water from the sun was so hot, that …

I have lived in homes where all of the domestic hot water was provided by the sun.  Other than showering in the afternoon instead of the morning, it is really no big deal.  In traditional homes, this super hot water, provided free of charge by the sun, can go a long way to heating the home, also.

6.  Boiler Replacement.  If you have a boiler, not a furnace, then consider a new boiler.  New boilers operate at 96% efficiency.  Old boilers commonly do about 55%-60%.  You can cut the heating cost in half.  I have paid off boilers in 3 years, so as a simple investment it is kind of a no-brainer.  I know that it isn’t sexy to, say, forgo buying that new car, but pay for the new energy systems first—the savings will pay for the car in a few years.

Again, the energy companies are not your friends.  They want for you to pay them to pump natural gas into your home and to generate electricity by burning coal to boil water to turn a generator so that they can run electrons through your wires.

7.  Boilers will do your domestic hot water.  If you have a boiler you can easily add a zone that will heat all of your domestic hot water.  The boiler has vastly more power than a hot water heater, so it does so much more efficiently and cheaply.  You can also add a couple of cheap rooftop solar thermal panels, which will supplement this system, also.

 See the pattern here.  Make your system more efficient, then look toward the sun.  Don’t get all solar, first.  You will need giant, costly systems if you try to go all solar without getting efficient first.

 8.  Now that the gas (oil) hogs are eating less, get to the electric.   Here is a punch list of electric savings:

A.  Turn off your lights, silly.

B.  Hang dry most of your clothes.  You don’t need lines outside, just get a pile of plastic hangers and hang the clothes on a rod, on a door, on the shower curtain, even in the closet.  It will humidify your home and your clothes will smell great.  The dryer is one of the two big hogs in your home.  It takes seconds and saves you a bundle.

C.  Electric piggy number 2 is your refrigerator.  If you have an old one, get rid of it.  Get rid of the old on in the garage or basement, too.  We buy massive amounts of food in bulk to save money, then we spend hundreds keeping it cold or frozen for six months.

As a note to anti-regulation bozos, the refrigerator is the great example of how regulation can work in our favor.  Basically modern refrigerators use about 40% of the energy than those built in the 70’s.  Our scientists and engineers are smart, just give them the right problem and they can probably get it done.

D.  Hitch all electronic devices to power strips—in one or two easy locations--and turn the strip on and off as needed.  You can also buy a $5.00 timer so that you only have the power strip turned on during specific times.  Do it manually if you don’t want to do the timer thing.  I have built switches into my house so that I can turn off specific outlets that are likely to have charging devices or items like stereos that always seem to have something turned on.  This is impractical for many, but it makes a difference.  Think, how many clocks do we need?

There are billions of devices that are turned on, but not being used.  A power strip and an ounce of conscience would save us, as a nation, billions of watts.  

9.  Get that bill out again—After you have made some easy changes--how many watts do you use now?  Once you know how many watts you use each month, then you can predict the size of solar system that you would need.  It is much, much cheaper to simply turn things off than to buy another 1000 watts in generating power, I can show you this if you don’t believe me.

10.  Net metering!  In most places you now have net metering.  When you are generating power that you are not using, your meter runs backwards.  You are giving to the grid and other users can take advantage of your personal power generation.  Easy.  No political battles.  No giant federal programs for those of you that are celebrating ‘Confederate Month’, and no more infrastructure.  It is really quite brilliant.  The sun is shining and it is hot.  You aren’t at home, but your solar panels are generating power like crazy.  You are sitting in your office, and since your office is using electricity, and your home is making electricity and giving it back to the grid, you are indirectly contributing clean energy to the cooling of your office.

Think of the city as a giant tree and each rooftop as a leaf of that tree.  The existing electric grid is like the branches of that tree, so the system is already in place to distribute the power generated by individuals.

I know that I harp on this point, but the energy companies are hostile to this system because they no longer monopolize power generation in a world that is focused on utilizing solar energy.  Each end user has the ability to also be a provider.  It is naturally co-operative and about nearly as red, commie, socialistic as nature itself.

If you want a preachy, personal rant on the stupidity of the rhetoric of our times, then that is also free of charge.  I’ll even buy the coffee!

11.  You’re still on the grid, so you don’t have to pay for perfect.  These few easy steps, done over time by everyone, would cut total household fossil fuel usage by about 75%.  Maybe more.  It is important that everyone know that this is a smart investment in your own home, and not a moralistic expense.  This isn’t Buck Rogers technology, either.  It is off the shelf technology, particularly cost effective when installed in the place of outdated systems, backed up by the system that we all currently use and understand.  It is simple and insanely inexpensive when compared to the trillions of dollars that we will spend in order for the energy companies to provide us with energy that they produce.

If you have read this far, you are truly my people and I thank you!

Thanks.

Justin

26 April 2010 ~ Alternative Building Materials

Sorry I was away on vacation last week and lost time for blogging to the beach! While there I was thinking about a time when I was younger and had less responsibility and how I used to travel and live 'off the grid'. So when I came back to an email from a guy who wants to build a house out of shipping containers - well- I had a lot to say!

(There is often the urge - especially in the green or creative worlds - to use found objects or alternative products as building materials. In architecture school we all do projects of this sort. It is very mind opening for a designer to really work through the realities and fantasies of building.)

Below is part of that email:

I used to live in the high desert of Colorado (I lived in Crestone CO, in the Sangre de Cristos just north of Taos + Sant Fe) I lived there in a converted railroad box car. While there I built straw bale and adobes and pumice houses and earthshps (passive solar tire houses). So I am very familiar with building in the climate of the desert as well as that of Connecticut.

I have always been interested in container architecture and have done many designs with containers in mind and while I feel it is possible to get a pretty awesome house out them I think that it is only ideal for certain climates- like Los Angeles (where I also used to live).

The old box car I lived in in CO was an insulated/ refrigerated car. Awesome insulation in the walls and really nice raw wood lined the insides- walls and ceilings. This was a perfect 'container' to turn into a house - especially in the high desert where it is really quite cold half of the year. Not only was the car insulated but we burmed it into a hill on the north side and opened up a good deal of the south wall for passive solar heat gain. We poured a simple adobe floor to collect the sun's heat through the day. The wood walls we easily stained and they made for a beautiful warm interior. Because it was a box car it came with 2 rectangular cut outs in the roof - one at each end - used for adding ice to the box car. These we turned into beautiful sky lights.

Your average shipping container is not like this. The average container is all steel and only steel. There is no built in insulation and there is no beautiful exterior or interior surface as a given. Unless you live in L.A. you have to add insulation. (For either heating OR cooling). And unless you truly love the look and feel of cold rough steel as a wall surface you have to cover the interior and possibly exterior with something more appealing. (Drywall, wood paneling, cedar,etc). Steel can look really cool- especially slightly rusted- but really you probably don't want to lean on it or touch it a lot in your day to day living. It will always feel very cold.

 I could see a steel exterior but then you would have to add insulation to the interior and then a secondary wall inside to cover the insulation and so would lose a 4-6 inches all around the house on the inside. Containers are already small inside.Also you will have to cut openings for windows and doors and carefully craft the doors and windows to fit those opening and avoid leaks etc.

So what are you getting from a container? Structure. You are getting a structure and you are getting a potentially interesting house. You are re-using items that may otherwise go to landfills. You can stack them! You can arrange them, etc. They are inspiring to the designer mind. You will not get and average house for sure and that may be enough of a reason to take that route...but it is not easy or cheap really in the end. It would probably be more cost effective in a CT climate to simply build a stud wall box from scratch.

Actually- below is a picture of a house clad in steel (rusted - or 'corten' steel). It is not built out of shipping containers. (house by Simon Ungers and Tom Knislow)

Update on 2013-10-12 01:21 by Elizabeth DiSalvo

Shipping containers are designed to be water tight. If you insulated on the inside, the moisture would condense on the cold steel skin. If there was an interior vapour barrier, you would trap the moisture. It would probably be best to insulate on the exterior. In any case, reusing a shipping container (a former boss from Newfoundland called these seacans) is an interesting challenge.
Jim

06 April 2010 ~ House Parts - Windows

Not all Green houses are created equal. Some are 'greener' than others. We like refer to this as 'shades of green'. Of our 4 new houses I would rank them like this:

Rowayton and California: Super- dark Green! Definitely LEED certifiable Gold or Platinum. (Rowayton is the only house actually getting certified and we are hovering on the Gold /Platinum line) Both are extremely energy efficient, use low carbon footprint materials and construction and make good use of alternatives in the form of Geothermal (ground source heat pump), Photo-voltaics (electrical solar panels) and Solar Thermal Panels (hot water solar panels)

Westport: Very Green. This house would probably get LEED Silver at least.  Very energy efficient, mostly green materials and  products, and use of geothermal.

Greenwich: Light Green. This is a solid energy efficient house- much better than your standard house construction - but not extreme in its green measures.

(btw: LEED is a rating system that registers how 'green' a building is. You can go to this website to learn more:USGBC website

So what is the difference. Well, as Mies van der Rohe said 'God is in the details'. Its all about individual components, very specific construction details and methods and degrees of performance in products such as insulation and windows. Today we will look at windows:

Below is a photo of the windows at the Greenwich house. They are quality Marvin windows. Nice.

 

You can see from their sticker (below) that they get a U-factor of .32, a Solar Heat Gain Coefficient of .26 and Visible Transmission of .45.  The U-factor is like the R value of insulation. It tells us how energy efficient the window is. Solar Heat Gain Coefficient tells us how much of the sun's rays are getting though (You want the sun to get in if you are in a heating season and your house is designed for passive solar heat gain..you don't want the sun to get in because it fades the upholstery.) The Visibility refers to just that -how 'see through' the window is.

Films that are applied to make the window more efficient will lead to less visibility and less solar heat gain. So sometimes if we have designed a house to work in a passive solar way -yet still want it to be very energy efficient- we have to play a trade off game. Like maybe we decide to make the south facing windows less energy efficient than all the others so that we can get that winter sun in to heat up the house.

Here is a picture of the Westport house's windows:

 
They look very similar and are in fact made by the same parent company - Marvin Windows. These windows are - however- Marvin Integrity Windows. They get a U Factor of .29 or .30 depending on which window, a SHGC of .26 and VT of .46.

With U-factors, the smaller the number the better (the more efficient the windows). With this U Factor they are eligible to get the $1500 federal tax credit for energy efficient windows...but just barely.The u-factor needs to be .30 or less to apply. Next year I think they are lowering it to .28...I need to verify that. These windows meet Energy Star requirements (another sort of rating system.) 

These windows are better performers than the 'normal' Marvins on the Old Greenwich house. Both are double paned, Low-E glass and filled with Argon gas. The Integrities are primarily fiberglass frames with wood veneer on the inside where as the normal Marvins are primarily wood frames with aluminum cladding on the outside. Fiberglass is more efficient than wood, wood is more efficient than metal.The difference in U factors comes from other tings too- like what the spacer bar between the glass is made of and how the windows are assembled.

The Integrities are less costly than the normal (O.G.)Marvins. So why not buy them? Well many people don't like fiberglass windows (Integrities or anyone's) when they get up close and personal(too thin or flimsier than the normal Marvins.) But honestly I think they have come a long way! I think they look pretty darn good up close and personal these days.

(And just as a note- my Minnesota architect friends think that the Integrities don't even cut it as energy efficient windows. They usually spec triple pane fiberglass windows with no muntins (you know those window grilles that everyone likes so much). Those windows achieve U factors of .20 or .22 or sometimes even as low as .15 or .16!! Pretty amazing. But in our neck of the woods we have a more mild climate and it is not really worth the cost to get windows that are THAT efficient. (Although if you really want to live 'off the grid' you should go for it.) People usually are concerned about the R.O.I. (return on investment) and don't see the value.

BUT speaking of triple pane windows- lets look at the Rowayton house:

These windows are triple pane  Eagle windows with a wood frame and aluminum clad exterior. They get a U factor of .27. The best of our group. They achieve this due to the 2 air spaces between the 3 panes as well as having the low-E 4 glass. You can read about it here at Eagle Windows.  These windows cost more than the Integrities but less than the normal Marvins and they give the benefits of having a nice wood window with high efficiency.

The performance of the window in the envelope also depends a lot on how they are installed and how those gaps around the windows are sealed. We'll get into that more later...

01 April 2010 ~ Rowayton- Solar Day

Today we had the guys from C-Solar out to the Rowayton,CT house to map out the PV and Solar Thermal systems. The roof faces due solar south- perfect orientation - (because we planned it that way!)and we have 2 different roof slopes. The main roof will be optimal for winter sun PV and year round solar thermal. The big shed dormer provides and excellent angle for the summer sun. We can easily fit a 10kW PV system alone, OR 7.5kW PV system with 3 or 4 solar thermal panels for hot water. The guys are going to crunch the numbers (show us the rebates and tax incentive numbers and energy use estimates) and then the client will decide which way to go.

This house also has a geothermal system.

With these three systems working together- as well as the super energy efficient building envelope, LED can lights throughout, low flow plumbing fixtures, and energy saving controls - the client will see a great reduction of grid based energy use. We will tell you the exact break down of numbers later after all is up and running.

Now we just have to pick a floor stain color...

70 degrees and sunny! Happy spring.

Elizabeth