The Believe in Magic Gazebo

Down in the Hole

Down in the hole

Lord, it's deep and the sides are steep

And the nights are long and cold

Down in the hole

Light and love and the world above

Mean nothing to the mole

Down in the hole

James Taylor

What would the answer be if this question were asked of a group of four-year-old children: “What do you think you would find if you dug a hole at the beach that was 200 feet deep?” In my experience, the answers would range from the fantastic, “an underground sand creature that has a secret passage to the ocean”, the whimsical, “a special land where fairies had a magical kingdom,” to the mundane, “worms and dirt and maybe some dead stuff.” In truth, after watching the guys drill the holes for the ground loops, I think the answer is really just “more sand.” How about this one: “How deep is 200 feet?” Since the average American four-year-old child is about 3.3 feet tall, it would take 60.6 children standing on top of each other to make a tower 200 feet tall, even if the boys were standing on tip-toe. Put them down instead of up, and that’s a really deep hole!

On Valentine’s Day, Steve Van Horn and his Chesapeake Wells crew began the installation of the vertical loops for the geothermal heat pump. Vince and I took the dogs up to the house and sat on the walkover to watch the process. As Steve had told me earlier, his is one of the world’s dirtiest jobs. I would add the adjectives “cold”, “wet”, and maybe “tedious” to that description. Digging a deep well hole is definitely hard work!

At the beach, a geothermal heat pump requires a closed loop system, meaning that the fluid, in this case water, circulates through the loop fields’ pipes and does not pull in water from a water source. (Open loops would be subject to salt water intrusion.) The pipes run through the ground, but there is no direct interaction between the fluid in the pipes and the earth other than the heat transfer across the pipe. There are four choices for the shape of the ground loop system: Vertical, horizontal, and slinky (coiled), and pond. Because the beach environment is sandy and subject to erosion and overwash, vertical loops offered the best opportunity for damage control, and they obviously take up less horizontal space, so that was our choice. The length of loop required is determined by the ground formation, the ground temperature, the heating and cooling power needed for the house and the balance between the amount of heat rejected to and absorbed from the ground during the year. This determination was done our mechanical engineer. Steve dug eight wells that are about 200 feet deep, so there are about 1600 feet of pipe. (A well in this definition is a deep hole, rather than a place to fill your water bucket.) Although the tubing can be made from various metals, these pipes are polyethylene, also a common material for this use and more appropriate in the corrosive environment of the coast. The pipe pairs in the hole are joined with a U-shaped cross connector at the bottom of the hole. Oh, wait! That makes it 3200 feet of pipe!

Anyone who has tried to build a sandcastle knows how hard it is to create any kind of hole in the sand that will stay open, and the idea of a 200 foot deep hole seemed laughingly impossible, though I knew better than to say so. As it turns out, the borehole is commonly filled with drilling mud, a sodium bentonite clay that does a multitude of jobs in the drilling process. In the end, the clay surrounds the pipe both keeping the borehole intact and providing a good thermal connection to the surrounding sand for maximum heat transfer. Steve uses a product called Quik-gel, a sodium bentonite clay found in Wyoming. This is really neat stuff, and it can be used in outside stock ponds or lagoons, to prevent leaching in land fills, for waterproofing, on and on. Steve adds soda ash to the mixture when digging in a saltwater environment.

So, what happens, exactly, to make this possible? The well drilling rig uses a diesel engine to power an hydraulic pump. The hydraulic pump spins the drill string, a column of drill pipe that transmits the drilling fluid (via the mud pumps) and rotational power (via the top drive) to the drill bit. The drill string is hollow so that the drilling fluid can be pumped down through it and circulated back up the annulus (the void between the drill string and the formation). The drill bit has holes in it to allow the drilling mud to be at the site of the scour. As the hole is dug deeper and deeper, the clay coats the walls of the borehole. The bentonite clay is also a viscosifier, keeping the bits of shell and debris in suspension until they can be pumped out into the mud pit. The mud pit, in this case a horse trough, works as a settling tank for the debris, which is shoveled out before it can be re-circulated through the system. Thus, the mixture of clay and water is continually pumped down into the hole and the debris brought back out of the hole until the proper depth is achieved.

Finally, the ground loop pipes are fed down into the hole along with the same length of rigid CPVC pipe, which acts as a sort of guide for the flexible pipe. The CPVC pipe is then pulled back out, leaving the loop in place. After all the loops are installed, the loops are connected together in the form of a manifold, and the loop field is established. Finally, the loops are trenched in and fed into the house where they will be connected to the Water Furnace heat pump system. Voila! Oh, if it were only that easy…

Take a look at the guys in action:

How Will We Get to the Beach?

“Sponges grow in the ocean. That just kills me. I wonder how much deeper the ocean would be if that didn't happen.”

Stephen Wright quotes (American Actor and Writer, b.1955)

There is a wonderful children’s book called, How Will We Get to the Beach? (Luciani & Tharlet, 2000) that is a puzzle story about a young woman named Roxanne and the five things she wants to take with her to the beach. It’s a bright, delightful book that is fun for young kids, and the evolving story clearly shows how solving one problem doesn’t mean that all the other problems will politely follow suit. When thinking about the outside spaces for the house, there were similar things to consider: How will we get to the beach, and how does that impact where to put the doors or where the outside steps might land? We decided on big screened porches on the upper and lower floors on the south side, a porch with a shed roof over the entry on the west side, a small screened porch off the master bedroom upstairs on the north side, and an unscreened porch off the studio downstairs on the north side. There is a deck area between the first floor porch and the walkover on the south side, a walkover that travels from that deck to the beach, an outside shower off the walkover, and an octagonal gazebo down near the dune line. Each space and the pathway to it brought a series of different problems to solve and issues to consider.

Our decks and porches have been built primarily by Jim Berge, who works for Currituck Construction. Jimmy is really a deck specialist. He is absolutely meticulous in the way he puts materials together, and that pride clearly shows in his workmanship. On some sections, especially the walkover and gazebo, Jimmy has been working with Stuart, another excellent carpenter from Currituck Construction, but he seems to prefer to work alone. Both men take the time to do a great job, and they are good folks, too. We appreciate them and look forward to enjoying the spaces they have created for us.

Screened porches were a given from the very first conversations about the house. The climate on the Outer Banks lends itself to spending time outside much of the year, and we wanted ways to dine al fresco, for visiting children to have a place to play and for my Aunt Earlene to be able to smoke cigarettes without worrying about mosquitoes. We have envisioned the porches as places for puzzles, snacks, cups of coffee in the morning, glasses of wine in the evening and a lot of good conversation all through the day. The Currituck Beach Lighthouse is visible from the upper porch on the south side, and that will be a friendly beacon to watch in the night. Deciding to add porches off the north (i.e. stormy) side of any ocean front house can be problematic, so those are something of a calculated risk. Vince worked with Rick House on the structural bits and pieces to keep out the wind-driven rain and to protect the main house if the porches are lost. There will be many sultry summer days when the cooler breezes on the north side will be much appreciated. Admittedly, the north side porches were long a part of our imagined life while dreaming of the house, especially the one off of our bedroom with its image of the perfect place to start and end a day. The porch off my studio will not be screened, because I wanted one place to step outside in the shade without being closed in even by screening. We have one neighbor who is planning to call me every time there is a nor’easter to say, “I told you so,” regarding those north porches, and I am planning to call him with my own, “I told you so,” when the delicious north breezes turn that beach into paradise.

For many years prior to building our own house, Vince and I spent time a lot of time driving around looking at different styles of beach houses to get ideas. We also rented houses in the area where we are building both to be sure that our decision to live there was viable and to look carefully at what works well in a beach house and what doesn’t. We rented a house called Bear Inn that had a level walkover from the house out to the dune with an octagonal gazebo at the end. That was wonderful! Both things were integrated into the house plans, with the walkway and the gazebo as high off the ground as the first floor of the house. That will be fun! In the years of looking around, I began to notice a common quality in many houses that became a pet peeve: Lovely houses had oddly rough decks with rusty nails poking out. Vince began to look for a solution to that problem and finally found a product called Timbersil (http://www.timbersilwood.com) made from a process that combines yellow pine with glass. One huge advantage is that anything made from this material should continue to look good and function well for many years, especially with this use of Type 316 stainless steel screws. Timbersil is Class A fire retardant, unaffected by seawater or insects, and it is GREEN! Sounds too good to be true, but it’s real and a good choice for our environment. The budget for Timbersil ran out at the end of the deck, so the walkover and gazebo are made from double-treated MicroPro. (http://www.osmosewood.com/micropro/micropro.html)

Take a look at these videos to learn more about Timbersil:

One problem in attaching decks to houses is the gathering of moisture between the house and the deck at the point of attachment, causing rot. It is important to have an offset between the deck and the house to provide airspace. This airflow allows the house and the decking to stay dry, providing a much less vulnerable spot in the structure as well as a much less habitable place for insects. Maine Deck Bracket makes an effective product that all of the guys on our building site really liked. The bracket is made of a highly corrosion resistant tempered aluminum that will not rust and is securely bolted to the house. The number of brackets, type of bolts, and spacing of the brackets is determined by the load they must carry, so care must be taken in both the decisions and the installation. Here’s the link: http://deckbracket.com/

My two most important personal dreams for the house were the octagonal gazebo and a bathtub…both thoughtful spots. I know there will be other places to be comfortable with a book , a camera, or a journal, like the porches, the window seat, or even sitting on the steps at the window wall. I hope that will be the gift we can give our friends and family: a place to breathe easy and think good thoughts...and Vince’s wonderful food.

Up on the Roof

Tevye: A fiddler on the roof. Sounds crazy, no? But here, in our little village of Anatevka, you might say every one of us is a fiddler on the roof trying to scratch out a pleasant, simple tune without breaking his neck. It isn't easy. You may ask 'Why do we stay up there if it's so dangerous?' Well, we stay because Anatevka is our home. And how do we keep our balance? That I can tell you in one word: tradition! Without our traditions our lives would be as shaky as, as... as a fiddler on the roof!

From the play, Fiddler on the Roof
1964

The main reasons for having a roof on one’s house are obviously to keep the weather out and to have some control over the environment it covers. Although time will tell, our trussed hip roof is designed to be a secure system. The completing step is to use an outer skin that will do the job of preventing heat, cold, wind, or wind driven rain from leaking in and heated or cooled air from leaking out. In a High Velocity Hurricane Zone, it is important to use a roof covering that will not blow off or puncture during a storm, as well as an underlayment that provides a sealed skin over the roof deck in the case that the covering fails. Essentially there are two parts to a roof system, with the outer skin and covering protecting the underlying framework. The wooden part of the roof structure was put together by the framing contractor, Currituck Construction Company, and the outer layer will be completed by the roofing company, JBH Roofing, Inc. However, even the very best contractors can’t prevent storm damage if the roof design and the systems within the house are not carefully planned to maintain the integrity of the roof.

A primary goal for the roof on one’s house would be that it not have a hole in it, but that simple concept turns out to be quite a challenge. In fact, most roofs have more than one hole: dryer vents, roof vents, plumbing vents, range hoods, fireplaces, heating system vents, left-over pump-jack holes…lots of possibilities, including vented soffits. Our house was designed to minimize or eliminate any possible roof penetrations, and Vince worked with the sub-contractors to find ways to vent the house systems either through the west wall or through the south porch roofs…so far, so good. Using the spray polyurethane foam insulation applied directly to the roof deck eliminates the need for venting the roof by taking away any heatable air space between the roof deck and the insulation, so there will be no penetrations for roof vents and no vented soffits. A resulting benefit is conditioned storage space above the ceiling. The porches are built to be sacrificial, meaning that if they are lost in a storm, the main house will remain intact, including the roof.

The next task was to decide which underlayment and which outer covering to use on the roof. Metal roofing is a great choice in a hurricane prone environment, but for us (i.e. at our age) the costs outweighed the benefits. We chose the GAF-ELK Timberline Armorshield II shingles, which pass ASTM D3161 wind test Class F at 120 mph and ASTM D7158 wind test Class H at 150 mph. These heavy shingles are also rated Class 4 for impact resistance (that’s the highest) and Class A for fire resistance. They pass muster for Miami-Dade and the Texas Department of Insurance, so there’s good reason to expect them to do well in North Carolina. Oddly, these shingles are not sold in North Carolina, so we bought them from Texas. There are several different warranties available, but the testing was much more significant in this decision that was the warranty.

Vince wanted a continuous membrane for the roofing underlayment and chose Grace Ice and Water Shield. This membrane is composed of two waterproofing materials – an aggressive, rubberized, asphalt adhesive backed by a layer of high-density, cross-laminated polyethylene. The adhesive bonds tightly to the roof deck, creating an impermeable surface. The rubberized asphalt seals around roofing nails, resisting leakage. Our specifications called for Type 316 stainless steel ringshank nails, so that corroding fasteners would not create a gap in the underlayment. Ice and Water Shield is also slip-resistant, so I felt better about the guys walking around up on the roof.

The biggest frustration in trying to protect the roof from penetrations has been from the use of pump-jack scaffolding when siding the house. A pump-jack scaffold consists of a platform supported by moveable brackets on vertical poles. The support braces for the scaffold are screwed into the roof, with approximately four screws per support. That’s a lot of holes! Generally, the pump-jacks are attached through the shingles near the edge of the roof, so there are holes that go through the shingle and through the underlayment into the roof deck. Unless those holes are carefully repaired, wind-driven rain will easily find a path into the roof structure. On the east side of our house, the pump-jacks were removed before the shingles were applied, and each hole through the underlayment was sealed. On the west side of the house, the pump-jacks were removed to apply the shingles and then put back through the shingle after the roof was completed. I have asked for that row of shingles be replaced and the holes in the underlayment to be resealed. From the perspective of someone just observing the process, I have to say that it a foolish system. It makes much more sense to finish the work with the pump-jacks and then to put on the outer skin of the roof. Why voluntarily punch a hole in the roof? Aagh!

The key to feeling assured that the roof will not leak is to find a certified roofer and to talk with him about the many different aspects of the job before that roofer is hired. The roofer recommended to us by our general contractor was Jason Hill, whose company is called JBH Roofing, Inc. Jason has really been “on board” with the goals that we have for the house. It was Jason who taught me about the pump-jack problem, and it will be Jason who makes sure the roof is intact. Jason and his brother, Brian, met with us to talk about choices for shingles and underlayments, and he has been carefully attentive to the specifications and details along the way. He is an authorized GAF residential roofing installer, so we felt confident that he knew the GAF product applications well.

In addition to being a great roofer and a good person to be around, Jason is a gifted visual artist. He has been a student of Glenn Eure, a veteran artist who owns and exhibits works in his Ghost Fleet Gallery in Nags Head, NC. Glenn has given Jason not only the gift of his teaching but also the gift of his friendship in mentoring a budding colleague. Vince and I have commissioned Jason to create a piece for the new house, and we also plan to purchase a couple of the paintings and prints that are now available. The work is what Glenn calls “non-objective abstract in mixed media,” because Jason begins without a specific goal in mind, allowing it to unfold as he works with the shapes, colors and materials. I took some photographs of a selection of his pieces and created a slide-show video from those that I saw. Take a look. It’s really beautiful work, and we are honored to have this part of Jason’s spirit within our house…and on its roof!!!

Splish Splash: Getting Ready for a Bath

BATH, n. A kind of mystic ceremony substituted for religious worship,
with what spiritual efficacy has not been determined.
Ambrose Bierce,
The Devil’s Dictionary, 1911

I have read that some people as long ago as 3300BC and as far away as ancient India and Rome had plumbing systems and bathtubs and even flushing toilets, but my own North Carolina history is dotted with outhouses, hand water pumps, and homemade soap. My step-father, born in 1901, chuckled as he told us a tale about how he and some other boys turned over the outhouse at school around 1913, only to find that the Principal was inside! Turns out that tipping over outhouses on Halloween night was also a popular prank back in the 1930’s, but the kids had to be careful not to fall in! My mother grew up with an outhouse that was used during the day and a chamber pot to be used during the night. She can describe vividly how very cold it was to use one if you had to get up on a winter night in an unheated house. Anyone who has ever hauled a heavy, bucket of dripping water knows what a wonderful thing it is to turn on a faucet and have water flow from it like magic. Being near a water source is necessary for life, and being able to have a system of pipes that brings water into the house definitely makes life much more comfortable and convenient. Those pipes keep the world a cleaner place as well, especially since throwing waste out a window from a chamber pot was still common practice until the early 1900’s. Many of us remember hearing the old saying for a person who was either a n’er do well or had a poor economic background: “He didn’t have a pot to piss in, nor a window to throw it out of.”

The United States has made a lot of progress in plumbing in just a century, most of it since World War II. For a while, pipes were made from hollowed out logs, then came lead, ceramic, copper, concrete, galvanized steel, brass, ductile iron, and plastics. Sealants have been explored and modified, changing as pipes have improved from oakum (a mixture of pitch and hemp or jute fiber) to rubber gaskets, solder for copper, and now adhesives that fuse CPVC pipes together. Today, not content to simply have water piped in and waste piped out, we like for the water to be clean, tasty, hot or cold, with a sufficient amount of water pressure, and piped through a system that doesn’t leak, decay, or house bacteria…and that is also environmentally friendly with good conservation.

The system chosen for the new house is a Home-Run Plumbing System, and our plumber of choice is Gary Ballard, of Ballard Plumbing Company in Harbinger, NC. Although the Home-Run System is new to the Outer Banks and new to Ballard Plumbing, Gary and the crew did a beautiful job of putting it together well. Here’s how it works (with a nod of thanks to the Internet): Home-run systems act as control centers, or manifolds, for hot and cold water that feed supply lines to individual fixtures. They consist of a plastic or metal plumbing manifold and flexible plastic piping. Generally, home-run systems use cross-linked polyethylene piping (PEX), which is suitable for hot water use and resistant to temperature extremes, chemical attack, and creep deformation. Because of the flexible piping, home-run systems can be installed more quickly than rigid plumbing systems, with only one fitting at the manifold, one transition fitting at the fixture, and no need for piping tees and elbows. However, fittings and couplings are available for special situations, such as repairing damaged piping or creating changes in direction that are tighter than the minimum bend radius allowable for the piping.

A manifold plumbing system is similar to a breaker box for the electrical system in the home. The manifold provides a common location from which all the plumbing fixtures are supplied. Some manifolds feature fixture shut-off valves allowing the user to stop water flow to individual fixtures from one location. Others are termination manifolds, which may feed the plumbing requirements for a room or set of rooms and reduce the number of fittings required in the plumbing system.

Home-run systems equalize pressure, which allows for several fixtures to be used at the same time without dramatic changes in pressure or temperature. No more getting scalded in the shower because your spouse decides to brush his teeth at the same time! In addition, PEX piping can be sized 1/8” smaller in diameter than piping in a “tree” type conventional piping system for some fixtures. That means that hot water arrives at fixtures faster, and less hot water is left standing in the pipes after a draw. PEX piping can reduce heat loss from water in the pipe because it is a better thermal insulator than copper. Because manifolds are installed in easily accessible locations, plumbing upgrades and repairs are simplified. Each outlet from the manifold typically has its own valve, making repairs at the fixture much easier.

Some care must be taken with PEX tubing. It may melt, distort or crack if exposed to excessive heat, and should not be exposed to freezing or sunlight. Abrasive surfaces that can damage PEX should be avoided, and there should be at least 12” of vertical clearance and 6” of horizontal clearance from heat sources, like light fixtures and heating appliances. Manifolds should be installed near, but not too close, to the water heater, with minimum clearances of 36” vertical and 18” horizontal between a thermoplastic manifold and a water heater. Also, there is some concern that the closed-cell dense polyurethane insulating foam (containing isocyanates and polyols) may react with the PEX and cause premature failure, so it is wise to sleeve portions of PEX that may be exposed to that type of insulation. Take a look at: http://www.pexsupply.com/

If you are interested, there are several videos on You Tube demonstrating how to make PEX connections and install a manifold. Meanwhile, here's the Ballard Plumbing crew working on our house:

Air Supply

When I was a young teenager in general science class, my teacher tried to explain that color exists only when there is light. At the time I had a pink bedroom that in my mind stayed the same color all the time, day or night. Since every time I peeked at it in the night with a flashlight, it WAS pink, then obviously just because I couldn’t see in the dark didn’t mean the room was not pink. Right? Wrong! Sigh. I still struggle with that concept, but now I do understand it. I don’t like it, but I accept it. Comprehending what Vince has planned for what could literally be called “air conditioning” has been a similar struggle. My experience with heating systems has been more in relationship to the location of the thermostat than in understanding exactly how the warm or cool air is produced, and my habit is to simply open a door or window when I am uncomfortable. See the problem?

There are three big goals for the Heating, Ventilation, and Air Conditioning (HVAC) systems in the house: Climate control, efficiency, and air quality. This sounds simple, but there are a lot of factors to be addressed in each category. Temperature control is quite manageable most of the time, since the Outer Banks enjoys an average annual temperature of about 63 degrees and a comfortable indoor temperature would be around 72 degrees. There are fewer than 10 winter days of with temperatures below freezing and only a few weeks of weather that is 90+ degrees in the late summer. Controlling humidity is more challenging, with a high average annual humidity at about 75% and the comfort level for humans in a house between 40% and 60%. We humans make a habit of increasing that level in the house just because we breathe, move around, cook, do laundry, play, have pets, sit by the fireplace, on and on. As for efficiency, our only choice for continual power is electricity (with a back-up generator), because there are no sources for fossil fuels or wood in our area of the beach. Protecting the equipment is important as well, because being on the oceanfront exposes anything outside to a lot of variables, like heat from the sun, changing winds, exposure to salt air and a huge body of water that occasionally comes for an uninvited visit. In general the Outer Banks has very clean outside air, but maintaining good indoor air quality is a different challenge. Often, people don’t think about what they are breathing, but with the lack of air infiltration in a tightly closed structure and the amount of Volatile Organic Compounds (VOCs) and other emissions that are a part of modern life, indoor pollution control is an essential idea. As with the siding, solving one issue impacts another, so that the whole house is really an integrated sum of its systems, rather than of separate parts…like a person, in a way. Given these constraints, Vince decided to use a closed loop geothermal heat pump system aided by a whole house dehumidifier. He added energy recovery ventilators (ERVs) to assure an efficient system for maintaining good indoor air quality.

Before this project, the only thing I knew about a heat pump was that it doesn’t produce its own heat. In a nutshell, a heat pump moves heat from one source to another, and that source can be the outside air, water, or the earth. An air-to-air heat pump system is the most common, but often the difference between the outside air and the desired household temperatures overwork the heat pump and cause it to be less effective and inefficient. In an air-to-air system, the work
that the heat pump must do is greatly variable depending on the vagaries of climate, which makes it difficult to correctly size the heat pump unit. Water-source heat pumps are much more efficient than air-source units and are often used in large commercial buildings, but they require a fossil fuel fired boiler system to produce heat in the winter. For our use, the geothermal heat pump makes the most sense, especially since the earth where we are maintains a constant
temperature of about 61 degrees Fahrenheit starting ten feet below the surface. Another benefit of a geothermal system is that the compressor and heat exchanger sit inside the house, where they will not corrode. Very important for a salty area. This article and illustration from the Consumer Energy Center has a very clear explanation of a closed loop system:

http://www.consumerenergycenter.org/home/heating_cooling/geothermal.html

Here's a video that illustrates how a heat pump works:



and another about the geothermal system:

Our choice for the HVAC sub-contractor was R.A.Hoy, one of the oldest HVAC contractors on the Outer Banks. (http://www.rahoy.com) In addition to being knowledgeable and experienced regarding the geothermal system, the guys are great to have around the work-site. They put in long days of continual work, but they are laughing and fun and happy to explain all they are doing in the moment. The installation supervisor for our job is Fred Marklin, with Toby and his apprentice, David, putting the ductwork together for the rough-in. It has been interesting to watch how something that looks like big Legos when it arrives in the truck comes out being neat and orderly installed. We had planned for the placement of the ductwork when we designed the house, but there still were challenges associated with feeding the hard ducting through the chase in the middle of the house and allowing space for insulating the roof deck on the top floor.

The ducting is rigid galvanized steel except for the last few feet of the branch runs, where the ducts are flexible aluminum. The rigid duct is harder to handle, but it prevents the trapping of dust in the system because it is smooth. To prevent air leakage and air infiltration, mastic was used where two pieces of duct come together, and in some places aluminum tape was used instead. The tightness of the duct lines also contributes to the indoor air quality, because the system remains uncompromised. In our house, all of the ductwork is internal to the house, so there is less opportunity for the growth of molds and mildew. Each duct is insulated with aluminum faced fiberglass batts.

The house will have two complete HVAC systems, one for the top floor and one for the bottom floor. Steve Jenkins, our mechanical engineer, determined the sizing of the heating and cooling systems using Air Conditioning Contractors of America (ACCA) Manual J-compliant software. Although the Manual J is a complicated calculation, it prevents the incorrect sizing of the system and lessens the possibility of an uncomfortable living environment and wasted energy. Steve also performed the Manual D calculations, which establish the correct sizing of the ducts. (These Manuals are actual books, which are alphabetically named technical instructions for many different HVAC calculations, both commercial and residential.) A temperature control system is generally sized to the maximum expected thermal load of the house, so that the system can handle the worst temperature conditions. Unfortunately, since the usual operation would not be running at peak capacity, the system can become sub-optimal in terms of function. Our response to this is to have a two-stage heat pump which can also operate as a smaller system that is a sub-section of the actual heat pump (about 50% capacity). In this case, the system runs longer but is better able to remove the humidity from the air. It is important to realize that an HVAC system in a temperate climate is cooling dominated. Vince decided to use the WaterFurnace Envision series geothermal heat pump (www.waterfurnace.com) based on his research and Hoy’s recommendation. Florida Heat Pump (http://www.fhp-mfg.com) and Carrier (www.Carrier.com) are also good choices.

Contrary to his Sicilian heritage, my husband has an avid dislike for humidity and decided to use a whole house dehumidifier. Steve Jenkins provided Vince with psychometric charts which graph the physical properties of moist air at a constant pressure so that he could properly size the dehumidifying units. The units of choice are made by Honeywell:

http://www.forwardthinking.honeywell.com/products/dehumidification/dehumidification_products.html

Basically, the dehumidifier is a small, self-contained HVAC system that takes moisture laden air from the return duct, removes the moisture from the air and then sends it back either to the return duct or to the supply duct. It functions like an air conditioning unit by compressing the working fluid which runs through the cooling coils. The moisture laden air flows over the cooling coils, and the humidity condenses on the coils and is drained off as water. Then, the newly cooled and dehumidified air is run over the heat exchanger from the compressor and rewarmed. As air is cooled, its moisture carrying capacity decreases, so the moisture can be extracted. Vince explains that the process is like that of thermal fog, when warm air flows over a cool body of water and can no longer hold the physical droplets of water. In the house, the humidity will be measured and adjusted by a humidistat, which mounts on a wall and looks like a thermostat but has a humidity sensing element.

To improve and maintain good indoor air quality, Energy Recovery Ventilators in two zones will be used to actively manage the intake of air from the outside and the exhausting of contaminants and humidity from the inside. An Energy Recovery Ventilator (ERV) is a type of air-to-air heat exchanger that not only can transfer sensible heat (temperature) but also latent heat (in water vapor). Since both temperature and moisture is transferred, ERVs can be considered total enthalpic devices. An ERV takes the heat from the current air and transfers it to the incoming air stream, moving heat between the two air streams whichever way it needs to go. These mechanical ventilation systems use fans to maintain a low-velocity flow of fresh outdoor air into the house (incoming air stream) while exhausting out an equal amount of stale indoor air (exhaust air stream). Fresh air is supplied to all levels of the house while stale air is removed from areas with high levels of pollutants and moisture. Models with heat recovery and moisture recovery transfer heat and moisture from the exhaust airstream to the incoming air stream during the heating season, and transfer heat and water vapor from the incoming air stream to the exhaust air stream during the air conditioning season. An ERV runs on a proportional timer that is set up and monitored by the person (in this case Vince) who determines the appropriate need for air quality control.

Here's a great video explaining how ERV's work:

In the next couple of weeks, the ERVs will be roughed in by Hoy, and the dehumidifiers will be added after the heat pumps are installed. The ground loops, obviously integral to the system, are schedule to be installed by Steve Van Horn at Chesapeake Wells later this month. We're getting there!

Not by the Hair of MY Chinny Chin Chin!

The third little pig met a man with a load of bricks, and said, "Please, man, give me those bricks to build a house with." So the man gave him the bricks, and he built his house with them.
The wolf came, as he did to the other little pigs, and said, "Little pig, little pig, let me come in."
"No, not by the hair of my chinny chin chin."
"Then I'll huff, and I'll puff, and I'll blow your house in."
Well, he huffed, and he puffed, and he huffed and he puffed, and he puffed and huffed; but he could not get the house down.

The story of The Three Little Pigs is an English folk tale first written in the 18th century, but it is thought that the story and the lessons are much older. In the category of “Lessons Learned,” realizing that stronger materials make a stronger house is an important one to have on the list. On the Outer Banks, the material used to keep the house from being huffed and puffed away is not brick but fiber-cement board, and it is not only the quality of the siding but also the quality of the installation that keeps the wind outside. Our house is being beautifully “dressed up” by Lewis Babb, who owns a company called Exterior Specialists.

Before the siding is attached, the house must be wrapped and “weathered in”. The product choices for both the house wrap and the siding came by working through a series of causes and effects as each decision’s consequences affected the next. One early decision with impact on the siding processes was the choice of a dense closed-cell polyurethane foam insulation that is sprayed on the exterior walls inside the house. The foam expands, filling any open spaces to provide a continuous, protective air barrier that eliminates air leakage, a primary cause of energy waste. It forms a virtually airtight thermal, sound, and condensation barrier. Since the exterior walls are eight inches thick, there will be 2 ½ inches of spray foam with the remaining space being filled with fiberglass batts. It would be cost prohibitive (and not very smart) to fill the cavity with foam with no appreciable gain in the quality of insulation. Using the polyurethane foam prevents water and water vapor from getting through the sheathing into the house, which means that any water absorbed by the sheathing would be essentially trapped. Wet sheathing = rot and mildew = an unwelcome and far reaching problem. The question became how to either assure that the sheathing could dry when it became wet or to prevent the sheathing from ever getting wet. After looking at the more traditional house wraps, like Tyvek and tar paper, Vince decided to use an impermeable application and chose Grace Perma-Barrier wall wrap to keep the sheathing dry. This Grace product is a self-adhesive, rubberized, asphalt/polyethylene waterproofing membrane that is applied directly to the sheathing. Correct installation includes a specific amount of overlap and “rubbing” the material to provide secure adhesion, and the butyl rubber adhesive literally melts into the house. With this product on the outside and the foam on the inside, the exterior sheathing is sandwiched between two impermeable substances. That sounds ideal, except that there must be a way to assure good air quality and for moist air that accumulates inside the house (people breathing, doors opening, washing machines, etc.) to get out. The answer to this problem is an ERV (Energy Recovery Ventilator) that is a part of the whole-house HVAC system. The ERV recaptures heat from the air stream and replaces it with fresh, cooler air through the use of an air-to-air heat exchanger. (More on that later!) Applying the Perma-Barrier was problematic because it was something different to the crew, and it required a lot of time and patience to put it on smoothly and to go back and literally rub the entire house for good adhesion. That’s a lot more work than just nailing up tar paper! Grace makes another house wrap product that literally sprays on like paint, but that would have been even harder to apply correctly in our windy environment.

Years ago, when beach houses were not used in the winter, the issues of mold and rot were almost non-existent. Since there was little or no insulation in a house, anything that got wet would be open to the air and simply dry out. Over the last fifty or so years there have been a lot of changes in how houses everywhere have been made more comfortable. At first there was just sheathing and siding (primarily wood or brick), and then there was sheathing and tar paper and siding, and now there is sheathing, house wrap or tar paper, siding, and insulation in the interior part of the house envelope. Insulation solved the problem of keeping the interior of the house more protected from the weather, but it caused the secondary issue of not allowing the sheathing to dry by reducing the air flow through the wall. Moisture and reduced air flow causes mold and rotting, and that’s the “circle” of dominos to work through.

One solution came in the 1960’s, when the National Building Council of Canada began to address problems associated with the deterioration of sheathing and siding. It had been noted that the air inside various structures was becoming increasingly humid, which indicated high water absorption. It was determined that the increasing water absorption was caused by advancing deterioration of the sheathing, which was then transferred into the house. A process was developed to create a physical separation between the siding and the sheathing, called a pressure-equalized rain screen wall. The concept is to deflect water absorption into the sheathing by tackling the forces that drive water into the building shell. By neutralizing these forces, rain screens can withstand extreme environments. The rain screen wall is created by the use of vented or porous exterior cladding, an air cavity of a few inches, and a drainage layer on a rigid, water-resistance and airtight support wall. Rain screens effectively "drain the rain" by controlling powerful building wetting forces-gravity, capillary action, and wind pressure differences.

Here’s how it works: The exterior cladding deters surface raindrop momentum. It is typically porous with several air bypasses. An airspace separates the cladding from the support wall. The airspace decouples most of the cladding from the support wall, thereby reducing splash and capillary moisture transfer. Protected openings (e.g., vents, or weep holes) positioned at the top and bottom of the wall promote convective airflow, allowing moisture to quickly drain or evaporate from the air cavity. The exterior face of the support wall is protected with a drainage layer to further protect against any moisture that bypasses both cladding and air cavity. The wall air tightness (i.e., sealed assembly) buffers the remaining differential air pressure force. A “pressure-equalized” rain screen wall means that the pressure between the siding and the sheathing becomes equal to the outside pressure. The velocity component of the wind has been removed, preventing the wind from forcing water into the house. Since the siding and the sheathing are no longer in intimate contact with each other, the siding essentially absorbs the momentum of the wind. (That’s why face-nailing the siding with stainless-steel ring shank nails is so important!) Water that penetrates the siding freely drains down the membrane-wrapped sheathing, and any water that doesn’t drain evaporates. Cor-a-vent siding vents have been added to help promote air movement along the rain wall and to prevent various critters from colonizing behind the siding. Additionally, stainless steel drip edges were installed along the bottom of the siding to take the draining water away from the house and prevent the soaking of the foundation.

Our siding of choice is Hardi-plank. Fiber-cement board was chosen because it meets the requirements of a tough coastal area, and Hardi-Plank was chosen because it has a resume that backs up its qualifications. It has passed Miami-Dade testing for wind gusts of 150 mph and is rated to withstand both large small missile impact with tested design pressures of +53 and -53 (pushing and pulling). Hardi-plank also has FEMA approval for use in flood prone areas and is fire resistant. Those qualities provide a lot of assurance from James Hardie Corporation, but a key piece is making sure that the siding is installed according to the specifications for hurricane zones. That requires a siding installation crew that is patient and attentive to detail. We also specified that type 316 stainless steel fasteners be used, because no siding can do its job if the fasteners fail. Hardi-plank also comes pre-painted using a process called Color-Plus Technology. This application is particularly good for use oceanfront, because the paint is applied in a controlled environment before the siding is exposed to moist salt air or sand, and it has a 15 year warranty. In a cost comparison, the pre-painted product adds a small percentage of cost over the unpainted siding and is a big savings over having the house painted after installation. Louis has also made sure that the end cuts are painted before the boards are put on the house to prevent moisture from wicking through those vulnerable spots. Since the recommendation for hurricane zones is that the siding be face nailed, that also means that the nail heads have to be painted individually… one of the less desirable aspects of pre-painted siding. For this house, the trade-off was appropriate, and the siding will always have that first controlled paint application to protect it.

At the moment, Lewis and crew are close to finishing up their piece of the job, and each step brings us a little closer to seeing the exterior or the house as we planned it. Years ago, when we were up at the lot planting grass, I would take Vince’s arm and say, “Let’s pretend that we really do have a house here and that we have had a wonderful walk on the beach together. We would take the steps up from the beach onto our walkover and head into the kitchen for a cup of coffee or sit on the deck with a glass of wine.” And now, that vision is almost a reality!