150 Years to 10

April 6, 2015

Houses should last a very long time.  The Knap of Howar was built approximately fifty-five hundred years ago.  Pueblos in New Knap of HowarMexico were built over a thousand years ago.  Saltford Manor House, in Somerset, England was built sometime in the twelfth century and is still occupied!  These houses are built of extremely durable materials like stone or adobe.  But even the wooden houses built in the U.S. are intended to last a very long time.  It is interesting to think that we don’t actually own our houses.  It is rare that a house is passed along from generation to generation endlessly.  We’re just borrowing the shelter for a time, and then it is likely that it will be sold and passed along to someone else.  My house – at least parts of it – has been around since the middle of the eighteenth century.  I don’t know the people who lived here before except for the nice lady I bought it from.  There have been a lot of lives and a lot of stories enclosed within these walls.

When it was built, heating was accomplished by individual room stoves.  A central, warm air coal system was installed with very large ducts that allowed the air to move around convectively because there was no electricity and no fans.  Coal fired, single pipe steam was added and that was eventually converted to oil.

Electricity was added with knob and tube wiring to a fuse box.  More recently that was converted to Romex.

Running water and indoor plumbing was added, requiring the installation of pipes and drains one of which finally rusted out in the deep, dark recesses of the crawl space this winter.

I added insulation and storm windows and some passive solar heat.

The point is that some of this house is still over 150 years old.  The world has changed.  Building technology has changed.  Materials have changed.  Comfort has improved.  Houses are adaptable.  But not all the materials are going to last 150 years.  Some things – like network computer wiring – change very quickly, lasting less than a decade.  Knowing that, we shouldn’t be creating new houses that require the removal of the 150 year stuff to replace the 10 year stuff.  Repair and maintenance is a fact of life.  There are cars like that and they are not always exotics.  The Dodge Stratus, for example requires jacking up the car, removing the driver’s side front wheel, removing the inner fender skirt, in order to unbolt and replace the battery.  Not that a car is going to last hundreds of years.  We should not have to throw the car away because the battery dies.  If we are to be good stewards of the planet, knowing that things break and maintenance is required, we should build in such a way that conserves the good, solid, 150 plus year materials.

Quality Control should be more than just getting the job done.  Every time we work on a house we should think about the legacy of what we are providing for the future.  There is going to be love and sadness, laughter and joy and history will be made within the walls and that is not something to be treated casually.


If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.  Scheduled for publication on June 1, 2015.  For updates and a discount on publication, please add your name and email address by clicking on the book below.

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Visit us at www.HeyokaSolutions.com

 

Client Satisfaction – It’s a hug!

March 30, 2015

Mrs. Schroeder met us at the door in her thin, cotton housecoat with a welcoming smile. She lives in a small, bungalow on a back street in Trenton, NJ. It is a single story house with two bedrooms, living room, kitchen, and a room that serves as the primary storage for a lifetime of magazines, newspapers, Christmas decorations, and other stuff.

Mr. Schroeder built the house – a cozy, story-tale nest for his family and a lifetime of memories. He died a couple of years ago. He believed in ventilation and bathroom fans and installed one in every room in the house venting into the attiSchroeder Bath fanc. The attic floor is covered with fiberglass insulation that had settled to a dirty, dusty, two or three inches. The furnace in the dirt-floored basement is crowded into a corner with more stuff and a washing machine and dryer.

Mrs. Schroeder lived there comfortably for fifty years. But then Mr. Schroeder died, winters seemed to get colder, money got tighter. You know, they say that if you put a frog on a pot of water that it will stay there happily. If you turn the heat on and gradually bring up the temperature, the frog will keep sitting there until it boils, not noticing the change in temperature. “It used to be okay! It was okay for years!” Mrs. Schroeder wasn’t comfortable any more. She wished that everything would go back to where it was.

This is what we face in many of the homes that we weatherize. The homeowner is comfortable for years. It’s their home – their memories, their castle, and the weatherization crew is disturbing that. The crew needs to respect that. The crew needs to respect the client’s possessions as though they were their own. Would they do a sloppy job if this was their mother’s or daughter’s house or where their grandchildren live? There are all the mechanics of measuring, testing, air sealing, insulating, but to the occupant, it is home.

As a Quality Control Inspector or Crew Chief you have to be able to communicate with clarity and empathy with the client or homeowner. You play a dual role: on the one hand you will be representing the client or homeowner in construction process. On the other hand you will be representing your company or your agency. It’s a difficult line to navigate. In the process, you will have to satisfy the client without damaging the reputation of the organization that you work for or your fellow crew members. Hopefully, you will come into this dichotomy being appreciated and respected by the crew. But you will have to establish a rapport with the homeowner. Add to that mix the noise, dust, and intrusion of the crew invading the house.

Mr. Schroeder liked bathroom fans, but they broke through both the thermal boundary and the pressure boundary and blew heat from the house into the attic. Mrs. Schroeder was proud of her husband for his skill and his cleverness. We left the fans in place, sealing in them, around them and over them. Making them into dormant ceiling ornaments.

How do you know if a client is satisfied? It’s as simple as a grateful hug. There’s more to comfort than temperature.


If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.

QCI Handbook Cover copy

Remembering Common Sense

March 23, 2015

A house is meant to be a shelter from the weather, a small, controlled subsection of the planet earth where a family can live safely and comfortably. Caves worked but they were hard to keep warm. But they mostly kept the rain off and blocked some of the wind. House design has advanced over the years becoming safer and more protective. Most of the time. There have been problems with chimneys, for example. A hole in the roof works to let some of the smoke out, but it was an improvement to enclose more of the smoke and guide more of it out. But there was a problem with wooden chimneys. Common sense dictated that chimneys be built of fireproof materials. In fact, many of the improvements in building science were dictated by common sense, wisdom, and skill. The problem came into it when unskilled builders decided that it couldn’t be all that hard and there was money to be made by ignoring some of the details. So rules and codes and standards were created.

Now there isn’t anything inherently wrong with having rules and codes and standards. The problem is that the focus tends to drift from why the rule or code or standard was created in the first place to developing rules and codes and standards just to regulate the rules and codes and standards. Let’s face it: we’re not perfect. And our rules and codes and standards won’t ever be universally perfect either no matter how hard we tweak and tinker and debate. Some people like a airconditioned thatchlittle more salt on their meat and some a little less. And some don’t like meat at all. One rule that covers all the ways to eat a steak simply wouldn’t work. We could have committees and conferences and technical papers ad nauseam but we would still never come up with the perfect rule. When a committee or a society or a club self-perpetuates by simply constantly making changes to a set of rules, the original point is lost. No doubt we are learning more and things change, but we’ve lost the link to common sense. There is no room in our rules or codes or standards for the application of common sense! And we need to just stop and try to remember why the rule or code or standard was written in the first place!

What is the fundamental, bottom line point for the existence of the ASHRAE 62 Standard, for example? (Having been on that committee for over ten years now, I feel that I have a right to use it as an example.) The Standard says, “This standard defines the roles and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable indoor air quality (IAQ) in low-rise residential buildings.” That sounds pretty reasonable. The basics of the standard are great – segmented and detailed to define important stuff. Why can’t we just finish it? Maybe tweak it a little once in a while as we learn more and technology improves. But a huge amount of brain power and hours of discussion and tons of paper go into the constant adjustment of the standard.

When a 747 is landing, it is important for the pilot to line the plane up with the runway accurately so that that little or no adjustment is need to keep the plane rolling straight when it touches the ground. At those speeds, any moderately radical change of direction would be disastrous. A consensus standard is the result of general agreement about diverse views. Can you imagine what would happen if a 747 was landed by a committee? A compendium of diverse views doesn’t always allow room for common sense.


If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful. Publishing date is June 1, 2015.  Add your name to stay in touch.  Thanks.

QCI Handbook Cover copy

KSAs – Teaching the ‘A’

March 16, 2015

What are KSAs?  Kosher Supervision of America?  Knights Saving Armadillos? In building science terms (and others) KSA is an acronym for Knowledge, Skills, and Abilities.  There is no question about the Knowledge part.  You definitely have to know what you are doing when you are working on a house.  You have to know about the concept of the “house as a system”.   You have to know how to do basic math.  You have to know what ACH and CFM mean.  That knowledge can be presented and learned.  You can read it in a text book or hear it from a trainer.

Attic soffit stuffing

KSAs in an attic

There is also no question about Skills.  You have to have the skill to operate a blower door or a combustion analyzer.  Once you know how to do it, you can develop the skill by continuing to do it.  Some people can play their manometers like Stradivarius violins.  That’s a skill.

And there really is no question about the requirement for Ability to get the job done.  The problem is that you can’t teach ‘ability’.  Ability is either there or it’s not.  No matter how much knowledge you have or skills you have learned, if you’re not able to do the job you can’t do the job.  It might be better, however, to consider that the ‘A’ stands for attitude.  Ability and attitude go hand in hand.  When someone says, “I can’t!”, does that really mean that they lack the ability to do the job?  Or is it that they lack the right attitude?  They don’t feel like doing the job or the task or the event?  You can’t teach attitude either.  Maybe it’s in the motivation.  Maybe it’s self confidence or desire or the reward for getting it done or the punishment for failing.

Imagine you are in a hot attic sealing duct work and you are there by yourself.  It’s the end of the day and you are tired.  It’s dirty and dusty and cramped and your legs hurt and your arms hurt and your head hurts from bumping it on the underside of the roof.  There is one last joint off there in a corner.  No one will ever know if you finish the job and seal that joint . . . no one but you.  You have the knowledge.  You have the skill.  And you have the ability.  But do you have the attitude?

A quality control inspector has to have the knowledge and skill and ability to read the crew members’ attitude.


If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.

QCI Handbook Cover copy

What’s Your Quality Control Mission Statement?

March 9, 2015

Even with the best intentions, mistakes get made.  The meaning of mistake is defined by your Mission Statement.  A Quality Control Inspector moves the result of a project one step closer to perfection.  To do that, the inspector has to be a generalist and understand all the aspects of the project and have the experience of making his or her own mistakes and have learned from them.  The weatherization of a home has many parts from an initial analysis to determine what needs to be done, to understanding the systemic nature of construction, to appreciating the needs and resources of the homeowner, to the capabilities of the crew performing the work, to the verification that the results match the initial expectations.

A Quality Control Inspector is a residential energy efficiency professional who ensures the completion, appropriateness, and quality of energy upgrade work by conducting a methodical audit/inspection of the building, performing safety and diagnostic tests, and observing the work.
Imagine that there is a small house owned by a nice old lady who is struggling to meet her bills and tolerating exceptionally cold 090831_1474conditions in the winter and excess heat in the summer, conditions that make her life miserable.  The house fits into the local weatherization program and a BPI (Building Performance Institute) certified energy auditor has visited the house and created a work order to make improvements.  He did a blower door test to measure the leakage, measured the insulation depth in the attic, determined the existing insulation in the walls, and tested the atmospherically vented combustion, gas fired water heater, furnace and oven for safety.  And the crew comes in and begins to work.
The weatherization crew consists of a certified Crew Leader and a good crew who perform consistently good work.  You are the quality control inspector on the job and during an in-progress inspection you find that the auditor mis-identified the building envelope and the installers are not insulating a wall between the conditioned and unconditioned space, a living-room and enclosed porch. They will complete wall insulation this afternoon, according to their schedule. If you stop the job, you will miss the completion time and extend the job.  If you don’t stop the job, will you be doing your job as the quality control inspector?

Life is full of compromises.  A compromise means that you give up something to accomplish something else.  It’s the greatest good for the greatest number kind of thing not the end justifies the means.  Someone on the crew needs to understand where the thermal envelope is and point it out to the Crew Leader.  Certainly, the Crew Leader should know.  The Leader should have pointed it out to the Energy Auditor because it was wrong on the work order.  The homeowner is the one who is going to lose out because she is completely unaware of the mechanics of the problem, although she may feel uncomfortable in that room.

As the Quality Control Inspector, you should be able to turn to your mission statement to answer this question.  If your mission statement is focused on cost effectiveness, then you have to weigh the cost impact of stopping the job.  If you mission statement puts the comfort of the homeowner first, then stop the job and do it right.  But you can’t know that you have achieved success if you haven’t defined what success means to begin with.

A mission statement defines the organization’s purpose and primary objectives.  If the mission statement says that your organization’s purpose is to provide the most energy efficient, comfortable, and safe homes to your clients, then there is no question about what should be done for this home

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If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.

QCI Handbook Cover copy

If we’re going to do the job at all, we might as well do it right!

March 2, 2015

Gas ChecksDespite our best intentions, everybody makes mistakes.  It may be from lack of knowledge.  It may be from laziness.  It may be from just not paying attention.  Some mistakes have no consequences.  Some mistakes can kill people.  There are a lot of skills that go into making a house more energy efficient.  You can learn the fundamentals of the laws of thermodynamics and how to operate a blower door or an infrared camera, but the only way you gain wisdom is through experience.  When you are in  a crawl space sealing up the ducting joints and there is one more joint way back in the corner that no one will ever see except you  and it is damp and dirty and you’re lying on the floor covered with building rubble, are you going to go back there and get the job done?  Are you just going to work your way back out of there, shrug your shoulders, and justify it to yourself?  That’s what KSA means: Knowledge, Skills, and . . . Attitude.  Some people say it’s Knowledge, Skills, and Ability.  And you do have to have the ability to get the job done.  But you also need to have the right Attitude.

Quality Control Inspectors are the last line of defense.  They must have the right attitude.  The energy auditor checks out the house and creates the work order.  The crew comes in with the crew leader and gets the job done.  The quality control inspector makes sure that the ‘i’s‘ are dotted and the ‘t’s‘ are crossed and . . . that last connection in the crawl space is sealed.  Sometimes the QCI is called in because there is a problem like excessive humidity on the windows.  Sometimes is just a matter of signing off on the job.  If everyone did their jobs perfectly, QCIs wouldn’t be necessary.  And who’s going to check the QCI?d

The BPI Home Energy Professional (HEP) certifications take a lot of knowledge, skills, ability (attitude), and experience.  You have to prove that you know a lot about a lot of things.  To assist in that process, I am creating a Quality Control Inspectors Handbook.  The National Renewable Energy Laboratories (NREL) Job Task Analysis (JTA), what the certification is based on, covers a lot of fundamental and soft skills.  The book will go through all the Domains and Tasks in the JTA as well as all the elements that are included in the BPI field exam.  There is a need for more QCIs to meet the states’ Quality Work Plans.  My goal is to provide a resource that can support these efforts.  If we’re going to do the job at all, we might as well do it right!

If you would like to stay updated on the progress of the book, click on Keep Me Updated!  QCI Handbook Cover copyThank you.

Ice Dams and Soffit Vents

February 25, 2015
Ice Dam

Ice Dam and Soffit Vents

 

Right now in Massachusetts people are going crazy because of the ice dams on their roofs!  A company has arrived from Minnesota that has steam generating devices and personnel that will climb up on your roof and melt the amazing amount of ice that is collecting in the gutters, weighting them down, backing the water up the roof, and leaking into the ceilings below.  Companies have produced melting products like salt that can be thrown up on the roof to melt the ice.  Why is this happening?

Obviously because there is an enormous amount of snow that has fallen on roofs in Massachusetts!  But this really only highlights a problem that festers every year.  Before we insulated attics we didn’t have ice dam problems.  Heat from the interior of the house passed through the ceiling, heated the attic, and melted the snow evenly.

To save energy (and money) we now insulate our attics so much less heat escapes from the house which is great for a whole lot of reasons.  If air sealing was done prior to the installation of the insulation, reducing the amount of air that moves through the holes in the ceiling, transferring warm, moist air from the house into the attic AND if the insulation is installed perfectly from one edge of the ceiling to the other, there wouldn’t be ice dams either because the entire attic would be almost the same temperature as outside and the snow would melt evenly.

Soffit and ridge vents were the solution to the imperfect installation of the insulation.  The idea is that cold air pours in through the soffit vents and sweeps up under the entire underside of the roof deck and pours out of the ridge vents.  Soffit and ridge vents are there to prevent ice dams!  The building code says that you have to have attic venting.

Soffit and ridge vents are designed to solve the ice dam problem only.  They are NOT going to cool the attic.  The building code is the same in Florida as it is in Massachusetts.  They haven’t had much of a problem with ice dams in Florida.  They do have a problem with hurricanes.

For ridge and soffit vents to do their job inducing an airflow up the entire underside of the roof deck, they have to have an unimpeded path from the soffit to the ridge.  Companies make baffles or chutes to guide the air from the soffit.  These are not easy to install effectively particularly on a retrofit basis.  And when the air sweeps in from the soffit and passes through the fiberglass insulation or blows back the loose fill cellulose, it reduces the insulation value at one of the most critical points in the thermal boundary: the tops of the exterior walls.  Consequently, heat flows up the exterior walls into the attic, melting the snow on the roof immediately before the roof extends out beyond the house where it is exposed to the outside air and cold on the top and on the bottom.  The snow melts, runs down the roof, hits the cold surface and freezes.  More water from melting snow moves down the roof, and collides with the ice dam.  The dam forms a lake above it and the water works it way back in, under the shingles, and drips down onto the ceiling and into the house.

How do you fix this?

Well you can’t do much inside the house until the ice and snow is gone from the roof.  Once that wonderful day arrives, you should try to resolve the problem so that it doesn’t happen again.

  • Before adding insulation to the attic, make sure that as many of the holes between the house and the attic are sealed.  It is a lot easy to do that when they aren’t buried under lots of insulation;
  • Make sure that the soffit and ridge vents are actually open and allow air to flow through them;
  • Install effective air baffles to guide the air from the soffit vents up the underside of the roof deck.  It is very hard to see because it is a narrow, triangular space at the eave and there are nails sticking through the roof deck, but it is vital that the baffles make contact with the soffit and seal the entry air into a pathway to the ridge;
  • Then add insulation to the attic.  Blowing in insulation is like painting the walls.  The hardest part in painting and insulating is the preparation.  Once that’s done, blowing in the insulation is quick and cheap.

You could consider insulating the underside of the roof deck with spray foam.  That is a more expensive process but can be quite effective.  Any of these solutions is cheaper than hiring a company from Minnesota to keep steaming your roof time after time!

 

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Please visit our website at http://www.HeyokaSolutions.com

Still to come: the BPI Home Energy Professional QCI Handbook

BPI Building Analyst and Envelope Professional Problems

March 11, 2014

IMAG0436

I just taught a BPI Introduction to Building Science course last week that included both the information required for both Building Analyst and Envelope Professional.  There is an enormous amount of complex information included particularly for someone who may never have been in an attic or framed a house.  It’s all new from the second law of thermodynamics to R value to convection and boilers.  We are asking them to take in and understand and retain all of that information which has likely been shoveled at them in a week-long course.

On top of that we are working off two different Standards.  There is some information that is in the Building Analyst Standard (17 pages long) and some information in the 1200 Standard (47 pages long) (which is still a draft).  I have serious doubts that many people will actually read the new standard and refer to Paragraph 7.8.1.12.1.1 to determine an action level for spillage!

And even more confusing is that the trainers have not been informed as to what needs to be taught for the tests, or if the proctors are looking for different things than the trainers think they are training for.

The 1200 Standard has removed the need for “values” – actual numbers for CAZ depressurization and draft (if it’s higher than x it’s good, lower, it’s bad).  And in fact draft doesn’t even have to be measured.  The standard only indicates if it’s bad if it spills.  Yet we are now asking for CO Airfree on some things and not on others and not all test equipment displays CO Airfree so it has to be calculated.  And the 1200 Standard says “The draft table is provided by permission of the American Gas Association” although it is referring to a table that is in draft form not to a level of pressure.  It is hard to tell what an auditor is supposed to do besides telling the homeowner that their boiler or furnace needs servicing.  Do we really need to have auditors buy an expensive combustion analyzer for that one measurement, something they probably don’t understand and can’t do anything about?

And for gas leaks we need a device that actually measures LEL which is not what the Leakator (the common combustible gas leak detector) does now so it is another piece of equipment students will have to buy and proctors will have to have available.

There are various other discrepancies that make these confusing issues a challenge to teach.  on top of those there are the various categories: Building Analyst, Energy Auditor and Home Energy Professional.  I had students go to the BPI website per my suggestion, and they down-loaded different knowledge lists.

We need an Intro to Building Science Course that one could attend to get an introductory Building Analyst Certification, Building Analyst 1.  That should refer to a “Getting Started Standard” that combined the good parts of both the old Standard and the new 1200 Standard.  The Getting Started Standard should be no more than four pages long.  Maybe it should have a bunch of pictures like the instructions that come with a new computer.

IMAG0434

I refuse to teach to a test.  I think the students should understand what they are learning and not just memorize numbers and hose positions.  But there should be a block of maybe twenty-five items that the beginning participants could be taught that would be clear and simple.  Do we really expect them to go to Section 7.8.5, ANSI/BSR Z223.1/NFPA 54, National Fuel Gas Code, Table G-6: CO Thresholds?

Please visit our website at http://www.HeyokaSolutions.com

Should a homeowner have control of the ventilation system?

January 25, 2014
Brightened Circuit 2

Sophisticated Control

Allison Bailes started this discussion on his Energy Vanguard site.  (Go to http://bit.ly/LRL43Q)  I was going to respond there, but there wasn’t enough room.  I used to build sophisticated controls that would do all sorts of wonderful things, but they got complicated and expensive.

You can feel the heat from a heating system.  You can feel the coolth from the air conditioning system.  You can see the change in daylight and know when you should turn on the electric light.  You can’t see or smell radon or carbon monoxide or PM 2.5 particles.

Heat is needed when it’s cold.  Cooling is needed when it’s hot.  Ventilation is needed . . . when?  When the bathroom is smelly?  When the bacon burns?  There is no one, single marker or flag for mechanical ventilation.  If there was, it would be simple to answer the question, “Should a homeowner have control of the ventilation system?”

So if a homeowner is going to control his or her ventilation system, how would he or she do it?  Manual control through an on/off switch perhaps coupled to a light in a bathroom?  This approach is equivalent to an occupancy sensor.  I did some tests of ventilation controls a number of years ago, and a manual control like that had exactly the same impact on the humidity in the bathroom as having no fan at all.  No impact.  Might as well not have a bath fan as far as humidity is concerned if you’re going to control it with a light switch.  It might have some impact on methane, but I don’t have the data on that.

Manual ventilation control will not work well because we can’t tell people when they should turn the fan on and when they should turn it off.  And when (or if) they ever turn it on again.

So that leaves the alternative of automatic control.

A standard humidity control will turn the fan on when the humidity rises above the set point.  What’s the set point? 70% RH (like 70 degrees F)?  55% or 30%?  Do you change the set point seasonally?  Do you change it on the same days every year like the change in daylight savings time (or putting fresh batteries in the smoke detectors)?  Will the fan run all the time in hot humid weather?  In my control tests, a humidity control that was set to turn the fan on at 43% RH and off at 41% RH ran for 20 minutes on the day that I tested it.  If I had set it to turn on at 41% RH and off at 38% RH on the same day, it would have run for 9 hours.  Relative humidity is difficult to explain under any conditions, but constantly adjusting the RH set point is not an effective way to control the ventilation system.

CO2 might be good for occupancy, but it is certainly not the only reason to ventilate a house.  I built a ventilation control that used a mixed gas sensor.  We called the “Flatustat”.  Works great.  The one in my bathroom has been operational for the past 20 years or so.  We could create a control that responded to a any number of IAQ conditions, but they would be expensive, and it is difficult enough to get people just to invest in mechanical ventilation in the first place.  Price is definitely a barrier.

So how about quasi-occupant control with a timer?  How should it be set?  The ASHRAE 62.2-2013 Standard says that if you’re going to run the fan half the time you need twice the airflow.  If you’re going to run the fan one third of the time, you need three times the airflow.  If you’re going to go beyond a three hour on/off period, you’re going to need to do some more calculations which depends on the ventilation effectiveness and air turnover and the fan gets really big.

But why do that?  The energy saved for most systems by shutting them off for part of an hour or even three hours, is small.  You could save energy by shutting off your clock when you weren’t looking at it. You could save energy by shutting off your doorbell when you weren’t expecting company.  Doorbell transformers use power just sitting there.

So why not just size the fan to meet the 62.2-2013 Standard and let it run all the time?  There is some weird psychological barrier to this really simple, basic, least expensive and logical solution.  The Standard says you have to give the occupant control so they can shut it off.  It’s their house.  They should be able to shut things off that they don’t want running, but there probably should be a sign warning of the consequences if they do that.

Someone once told me that the first thing many people do when they walk in the door of their home is to turn the TV on.  Maybe the ventilation system should be controlled by the same switch.  Turn on the TV.  Turn on the ventilation system.  I’m glad that wouldn’t work for everybody.

You could think about the ventilation system as a scuba tank.  When you’re under water, you wouldn’t want to shut your air off for any period of time.  When you’re in a house (a contained volume of air that is continuously being polluted by waste air from people and possessions), you’re effectively under water.  Don’t shut off your air.  Keep it simple.  Take a deep breath.  It’s okay to let it run.

Check out our website: http://www.heyokasolutions.com/

Coming soon: Average and Effective Air Change Rates: One Limburger at a Time

Should a homeowner have control of the ventilation system?

January 24, 2014
Brightened Circuit 2

Sophisticated Control

Allison Bailes started this discussion on his Energy Vanguard site.  (Go to http://bit.ly/LRL43Q)  I was going to respond there, but there wasn’t enough room.  I used to build sophisticated controls that would do all sorts of wonderful things, but they got complicated and expensive.

You can feel the heat from a heating system.  You can feel the coolth from the air conditioning system.  You can see the change in daylight and know when you should turn on the electric light.  You can’t see or smell radon or carbon monoxide or PM 2.5 particles.

Heat is needed when it’s cold.  Cooling is needed when it’s hot.  Ventilation is needed . . . when?  When the bathroom is smelly?  When the bacon burns?  There is no one, single marker or flag for mechanical ventilation.  If there was, it would be simple to answer the question, “Should a homeowner have control of the ventilation system?”

So if a homeowner is going to control his or her ventilation system, how would he or she do it?  Manual control through an on/off switch perhaps coupled to a light in a bathroom?  This approach is equivalent to an occupancy sensor.  I did some tests of ventilation controls a number of years ago, and a manual control like that had exactly the same impact on the humidity in the bathroom as having no fan at all.  No impact.  Might as well not have a bath fan as far as humidity is concerned if you’re going to control it with a light switch.  It might have some impact on methane, but I don’t have the data on that.

Manual ventilation control will not work well because we can’t tell people when they should turn the fan on and when they should turn it off.  And when (or if) they ever turn it on again.

So that leaves the alternative of automatic control.

A standard humidity control will turn the fan on when the humidity rises above the set point.  What’s the set point? 70% RH (like 70 degrees F)?  55% or 30%?  Do you change the set point seasonally?  Do you change it on the same days every year like the change in daylight savings time (or putting fresh batteries in the smoke detectors)?  Will the fan run all the time in hot humid weather?  In my control tests, a humidity control that was set to turn the fan on at 43% RH and off at 41% RH ran for 20 minutes on the day that I tested it.  If I had set it to turn on at 41% RH and off at 38% RH on the same day, it would have run for 9 hours.  Relative humidity is difficult to explain under any conditions, but constantly adjusting the RH set point is not an effective way to control the ventilation system.

CO2 might be good for occupancy, but it is certainly not the only reason to ventilate a house.  I built a ventilation control that used a mixed gas sensor.  We called the “Flatustat”.  Works great.  The one in my bathroom has been operational for the past 20 years or so.  We could create a control that responded to a any number of IAQ conditions, but they would be expensive, and it is difficult enough to get people just to invest in mechanical ventilation in the first place.  Price is definitely a barrier.

So how about quasi-occupant control with a timer?  How should it be set?  The ASHRAE 62.2-2013 Standard says that if you’re going to run the fan half the time you need twice the airflow.  If you’re going to run the fan one third of the time, you need three times the airflow.  If you’re going to go beyond a three hour on/off period, you’re going to need to do some more calculations which depends on the ventilation effectiveness and air turnover and the fan gets really big.

But why do that?  The energy saved for most systems by shutting them off for part of an hour or even three hours, is small.  You could save energy by shutting off your clock when you weren’t looking at it. You could save energy by shutting off your doorbell when you weren’t expecting company.  Doorbell transformers use power just sitting there.

So why not just size the fan to meet the 62.2-2013 Standard and let it run all the time?  There is some weird psychological barrier to this really simple, basic, least expensive and logical solution.  The Standard says you have to give the occupant control so they can shut it off.  It’s their house.  They should be able to shut things off that they don’t want running, but there probably should be a sign warning of the consequences if they do that.

Someone once told me that the first thing many people do when they walk in the door of their home is to turn the TV on.  Maybe the ventilation system should be controlled by the same switch.  Turn on the TV.  Turn on the ventilation system.  I’m glad that wouldn’t work for everybody.

You could think about the ventilation system as a scuba tank.  When you’re under water, you wouldn’t want to shut your air off for any period of time.  When you’re in a house (a contained volume of air that is continuously being polluted by waste air from people and possessions), you’re effectively under water.  Don’t shut off your air.  Keep it simple.  Take a deep breath.  It’s okay to let it run.

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Coming soon: Average and Effective Air Change Rates: One Limburger at a Time