Category Archives: Infiltration

A Healthy Home Part 3 — Well Ventilated

Fresh AirA Healthy Home is well ventilated.  Everyone knows fresh air is important. This should be easy.  Well ventilated in more than just bringing in fresh air. The concepts are certainly easy, the details on the other hand take some thought and planning.  A new home ventilation strategy is fairly straight forward to design and implement. An existing home needs the input from the occupants and good analysis to address the problems. An effective ventilation strategy should address these issues in either new or existing homes.

  • Remove humidity, odors,, or significant problems from specific areas.
  • Remove stale, musty or other objectionable air.
  • Allow the occupants to choose fresh air sources that can be filtered or treated in other ways
  • Allow the occupants to choose to open windows when outside weather is appropriate
  • Allow the occupants to operate a system that can provide the amount of fresh air, to the appropriate places, in adequate amounts when needed
  • Provide fresh air when the outside air creates potential problems, such as Ragweed season or when other allergens are active
  • Provide air movement within the home, without the use of the expensive blower on the furnace or heat pump.
  • Allow minimal use of heating or cooling equipment during the shoulder seasons, when temperature changes are minimal, while keeping the home comfortable.

Billings QuoteHow much fresh air is needed?  Going back to the 1890’s, the number has been pegged at 30 CFM (cubic feet per minute) per person. This number was validated in a number of different studies and with the public health authorities in larger cities, dealing with large apartment buildings and recurring respiratory diseases.  I was pointed to the quote at the left by Allison Bailles. he located the original book on Google Books, page 20.

Beginning in the 1930s, research into changes in building techniques began to show the optimal number was closer to 15 CFM per person.  Some of the changes in construction included the increased use of forced air heating, moving from balloon framing to platform framing, increasing square footage, and the use of insulation in walls and attics. The formula changes from time to time and everyone has an opinion on details. The common point remains, fresh air is needed in every house.

Part of the Ventilation is removing air with a problem. Where is that?  Humidity is found in rooms that use hot water and basements.  Showers, tubs and cooking are the large sources of humidity.  The smells from food preparation and cooking can be very mouthwatering.  When the meal is finished and the refrigerator is full, the lingering smells become odors.  The answer is some spot ventilation in these areas. If your basement has a humidity problem, you can tackle that with a fitted sump pump cover to contain the humidity, and work to eliminate any water seepage.

vent fanSpot ventilation is a window that opens and an exhaust fan. The size of these fans is part of the formula that is specific to each home. The features of the fan are common to all homes.  It must be quiet. Builder grade fans are noisy. Noise in fans is measured in ‘Sones’. The Sone is a linear measurement of noise, compared to the decibels used by OSHA and others which is an exponential measurement.  Linear is better for quiet sounds, and decibels is better for loud noises. Fans should be less than 3 sones, and preferably less than 1 sone.  Reasonably priced fans are available that rate a 0.3 sones. A 1 sone fan is very quiet.

UnknownFans are certified for air flow and noise levels by the Home Ventilation Institute. HVI certification is very common and includes both the Sone rating and CFM rating.  When installing a fan, you must consider the duct losses that will occur in meeting the required air flow.   The rates for bathroom air flow  are 50 CFM, and 100 CFM for a kitchen.  Do not expect to buy a 50 CFM fan for a bathroom and connect it to 6 or 8 feet of duct work, and obtain 50 CFM.  I have measured 30 CFM routinely in these set ups.

Most people understand that various parts of their body are just a part of the whole.  If you start some type of therapy, there may be a side effect. Physical Therapy starts and you end up with some sore muscles, aha!  Side Effect!  Start a therapy for cancer and your hair may fall out, aha! Side Effect!  Your home works the same way.  Each part is just part of the whole. Change something, aha! What is the side effect?

House-System-imgAll of the items in the list above are part of the whole. For an existing home, some specifics of that house may indicate concentration on one or another of those areas.  A home built in the 1920’s will benefit from a different approach then a house built in the 1980’s.

A new home should have the ventilation system that meets the general points above.  The natural ventilation provided when windows and doors are opened, or the mechanical ventilation system that allows filtered and perhaps treated fresh air brought in from specific places and in specific amounts, allow the occupants to make the system work as they need.

 

This post is part of a Series on A Healthy Home

 

 

A Healthy House Part 1c: How Dry is Dry

rainIn Part 1a, we have looked at how your builder builds your home to keep water from the outside from damaging your home.  He used materials to shed the water and he lapped them over each other, from the roof peak and the shingles all the way down to the ground. And then directed the water away from the house, using gutters and sloping the landscape away from the house. Easy, quick and it looks nice.

In Part 1b, we looked at how your builder builds your home on the inside to keep water where you want it, and provide easy clean up when it does get out of the pipes, the sink, tub or shower.

BucketYou can think of this as bulk water.  You can see it, this is water that is usually measured in quarts or gallons, and it is responsible for 50 – 60 % of the water damage that occurs over time. The exact percentage depends on the source doing the figuring.  So why is there a Part 1c?   There is one remaining source of moisture in most homes.  Water Vapor.  Hard to see it, hard to measure it.  The damage water vapor causes is usually found to be very extensive.

If you have a roof leak, it usually ends up inside and you find it while it is relatively small. When it is fixed the damage is limited and fairly easy to fix.  Leaks from plumbing and over flowing sinks and tubs, is usually caught very fast. The surface is easy to clean up and many times contains the water.  Damage from these sources doesn’t really occur unless the water continues over time to get there.  It stays wet and is not allowed to dry out.

Flood type events are not really of concern here. When they happen, the homeowner is aware, his insurance may cover repairs and there are lots of contractors that will do the work. Generally, they have little to do with how the house was built.

teapotWater vapor is present in varying amounts in every home.  What is the relative humidity in the home?  40% – 25% – 65%?  That is water vapor in the air. We add to that from breathing, cooking, and hygiene activities, like showers and running hot water for various purposes.

How do we control this water vapor?

Spot ventilation.  This may be as simple as opening a window next to the stove where the pasta is boiling, or the tea pot is ready to pour. It may be using an exhaust fan over the stove to actually remove the water vapor from cooking out of the house. Same in the shower.

acWhen the heat and humidity arrive around here, in the summer, it is air-conditioning season. Most air conditioners will lower the temperature of the air and remove some of the humidity at the same time.  Somedays they do a great job, somedays the ac unit really has to work and it.  Occasionally, you will find a unit that makes the room fairly cold, and you just feel clammy.  Like you just walked in from 100° outside and you are wet all over. The trouble is, it doesn’t go away.  You keep feeling cold and clammy.

That is the first way that water vapor causes a problem with our homes, it makes us uncomfortable.

How does the water vapor move into the walls and attic to cause problems like the liquid or bulk water we looked at?  It has two ways to move.  Air Movement and Vapor Diffusion.

Vapor Diffusion involves moving a vapor, in this case water.  It involves temperature and pressure.  It also involves Math, lots of fancy math.  I know some math teachers that can run these numbers, and a couple of physicists here in Kansas.  I’m sure the characters on TV’s ‘Big Bang Theory’ could run the numbers.

Adding MachineThe good news is, we don’t have to run the numbers.  If you take a room in your home with the humidity at 40% and 70° –  you will find less than a gallon of actual water.  By the time all the numbers are done, the answer is:  Yes – Vapor Diffusion put some of that water vapor into the wall.  And we can test that the 7% moisture content of the drywall, studs and other parts of the wall, is now 7.5 or 8%.  Not much change.   If you have read much on this blog, you know I lower my blood pressure by turning wood, into bowls.  Anything less than 12% moisture content in wood is considered dry.

If the builder bought kiln dried lumber, and kept the rain off it, while the house was built, the wood is probably 8 – 9 % moisture content when the home is finished.  Kiln dried lumber is typically 6 – 8 %.  Moving from an enclosed type shed to the job site, wood will pick up a little moisture.

What about air movement and water vapor?  That is the one to take care of.  Uncontrolled air movement takes the water vapor right along with it. When that vapor comes in contact with a surface that is below the current dew point, it will condense and the liquid wets the material.  We know that energy savings is easy to obtain with air sealing.  So fixing the air leaks is good for stopping the water vapor from making our house wet also.   How much?  This graphic from the guys at Building Science Corporation shows how much.

Air_Vapor

This post is part of a series of posts on A Healthy Home.

A Healthy Home Part 1a: How Dry is Dry? –

rain

Water in a house, Good Thing, Bad Thing?  Some places like the sink you expect to find water. Other places like the floor, water is a problem. Builders work hard to build a home so water says where it belongs.

RoofLook at the way the roof is installed!  The shingles are layered from bottom to top. They are also lapped over each layer. So water, will drain down the roof and off.  If water gets up under a shingle, the roofing crew has done some other things like roofing felt, metal valleys and flashing to do the job.

Look at the water run off the overhang in the top picture.  When it rains most of the water hits the roof, the overhang changes how much strikes the wall. Matt Risinger, a home builder in Austin, TX, tweeted this graphic recently.

Overhang

Do you think Matt builds homes with short overhangs?

SidingThe layers on the roof are repeated for the same purpose for other areas of the house. They work the same way. Some are installed the same way, some are installed differently. Other areas of your home have a different experience with water.

Tyvek TopThe outer layer of a wall, the siding, like the shingles, are lapped. The next layer behind the lapped siding is usually known as house wrap. That’s the white covering you see on many new homes, before the siding is installed. Technically, the term for this is ‘Weather Resistant Barrier’ or WRB. Just as the roofing felt helps keep water outside on the roof, the WRB helps keep water outside on walls.

Just as the roofing felt, shingles, and siding are lapped; house wrap should also be lapped, each new layer draining onto the top of the layer below. The directions call for a 6 inch lap, and then tape. The tape is used on house wrap and not roofing felt, because it is a different material, cap nails should be used.

IMG_7672How does the home buyer know the house wrap is right? It passed a code inspection, didn’t it?  This image shows damaged house wrap. Is it taped and lapped correctly? Are the fasteners used according to the manufacturer’s directions.

Do these problems mean that house wrap is bad.  Certainly not!  House wrap is a great product when installed correctly.  It will do the job it is designed to do; act as a Weather Resistant Barrier. It will then, direct water back outside and not allow it into the wall.

DetailWindows and doors need an opening in the wall. These openings must be detailed correctly or water will enter. These details involve flashings, and tapes. How the window is made, with nailing flanges, with foldable nailing flanges or field installed nailing flanges must be considered. Here we see a tape used to seal the nailing flange to the house wrap.

Is house wrap the only type of WRB used?  No!  It is the most widely used in this area. The others will be covered in a future post.

Now if the roof and the wall properly shed water, and they guide any water that gets inside back out, we get to the ground. At this point the water should be directed away from the house.  Gutters and down spouts do a great job when the ground slopes away. Recommended slopes are 1/4 inch per foot for hard surfaces like concrete, and 1/2 inch per foot for other surfaces. Local codes may require more, or a builder preference may result in a larger grade.

damp_proofingThe basement or foundation walls should be damp-proofed on the outside. This is the black spray applied to the concrete. A tile drain system is installed around the exterior of the foundation and tied into a sump to be pumped out of the home.

 

If these or other equivalent measures are built into a new home, the builder is doing the job right. They are all in the building code. The issue is not what material, the issue is quality of workmanship.

This post is part of a series of posts on A Healthy Home.

 

 

 

A Healthy Home

Healthy HomeBuilding a new home, gives the homebuyer an opportunity to build in all the things they want. The floor plan, bedroom arrangement, windows are all important.

Also right up there is a house that is healthy. Everywhere you look, someone is pitching, this is healthy for you.  We have lots of buzz words for healthy.  Organic, whole grain, anti-oxidant, reduced fat, low sugar, wellness, all-natural are but a few. How do you make a house into a healthy home?  It starts with design and a few simple objectives.   Ideally, a healthy home is:

  • Dry
  • Clean
  • Well Ventilated
  • Combustion by-product free
  • Pest Free
  • Chemical Care
  • Comfortable
  • Safe

read beforeIt seems fairly simple.  We want a roof over our head to keep the elements out.  Hot or cold, rain or snow, we don’t want them in our home.  The dry home starts with a well constructed roof.  That keeps the weather related water like rain or snow out. Then the walls, and the foundation.

Clean may be obvious, or not. Well Ventilated and Combustion by-product free, along with pest free, no toxic chemicals, comfortable and safe seem also to be obvious.  There is a saying about the Devil being in the details.  It is certainly that way in building a home. So a few details on these topics that make up a Healthy Home are important.

I will be posting a series based on the Healthy Home. We will take a look at each of the points listed above and what they mean to the home owner.

Part Ia   How Dry is Dry       Bulk Water from Precipitation

Part 1b  How Dry is Dry       Bulk Water From other Sources

Part 1c  How Dry is Dry       Water Vapor

Part II    The Home Starts Out Clean

Part 3    Well Ventilated

Part 4     Free of Combustion Byproducts

Part 5     Pest Free

Part 6     Chemical Care

What % Of The Cost of a New Home Cost, Does The HVAC System provide? 5%, 10% ,15%???

This question was raised this morning on one of the professional discussion forums. Below is my response. Included is a link supplied by Richard McGrath in another response.

Let’s use a water bucket and a faucet for an analogy.

Take a page from the British Navy a few hundred years ago. They learned to tar the joints of their wooden hulled ships. Perhaps that’s why British Seamen are called ‘Tars’.

taringshipIf you build your bucket with wood, you do something to stop the leaks. To use the bucket, you have a faucet to put water into it. If you put less money into the bucket stopping the water loss, you will need to put more water into it all the time, and need a larger capacity faucet. That will cost more money. The reverse is also true.

The question is ‘what should our faucet cost’? Most people would look at it and say not much! For a half million dollar house you might get answers from 2-4%. Some would say less. A faucet system is not just the part you see sticking out of the wall? The system includes pipe from the source of water to the house, to the various rooms where water is needed. You can’t buy a $10 faucet and claim to have a faucet system.

For this question, you can’t buy a furnace and AC unit and claim that is the system. You must have a Thermostat and some way to get the heat and cool to the various rooms of the home. For an effective faucet system, you put some thought and effort into the design. The same goes for an HVAC system.

What is the bucket in our house? Sometimes it is called the thermal envelope, sometimes Thermal Enclosure. It is formed by a continuous thermal boundary that is aligned with a continuous air barrier. Pretty simple in concept, Not as easy to execute. Put some time and effort into the design; then put some effort into the execution.

Choose your insulation types and amounts carefully.  Each have advantages and disadvantages. Air seal the building. All fibrous insulation types allow air to flow. That flow will decrease or eliminate the value of the insulation.

Properly flash and seal the openings for windows and doors. Specify the U-factor and SHGC for the windows. Calculate the correct overhang for the eaves. You want to have them cast a shadow over the whole window at noon on June 21st.

Properly air seal the home. Install your WRB (water resistant barrier) correctly. That means following manufacturer’s directions. Wrap types mean gasketed nails, properly lapped and taped with approved products. You can use factory applied WRB to the OSB or a site applied liquid to the house. Air sealing doesn’t stop there. Fill each 1 inch hole the electrician drilled with caulk or foam, most wires running through those holes are about 1/2 inch. Then seal the joints of the wall and ceiling drywall on the attic side. Caulk or froth pac work. You can flash 1 inch of CC SPF also.

Now your house, bucket, is not very leaky. So you don’t need a big faucet. Big faucets relate to size of the HVAC system, they also directly relate to the cost to install. You also have the cost to operate.

After you have a well built air leakage controlled envelope, then you can consider the HVAC system. ??Two choices to start with: Hydronic or Forced Air. Forced air is most common in this area, we will persue that route.

After choosing Forced Air, you can choose gas fired heat or an electrically driven heat source. Again 2 choices. ??With a gas fired heat source you will have conditioned air leaving the ducts at 100 – 110° F. With an electrically driven source the air will leave the ducts at 85 – 95° F noticeably cooler. That will make or break many people on their choice and ultimate satisfaction with their HVAC system.

Gas fired comes in primarily Natural Gas and Propane. Availability is the key here. ??If you choose a gas fired system – go sealed combustion on the furnace and either sealed combustion or fan assisted drafting on the DHW.

If you choose to go with an electrically driven system, you can choose a Heat Pump or an electric furnace. If you choose an electric furnace, IMO you will not be pleased with your operating costs. They will be through the roof and you will invest any capital cost savings in operating costs very quickly.

That leaves a heat pump with Two Choices. You can choose an Air Source or a Ground Source. ??With a well designed and built duct system, meeting the standards for leakage and design for the Energy Star 3.0 program; a ASHP with variable speed ECM motor (which may be overkill) including actual Manual J, S, and D work ups around here will cost between 9 – 15 K. A gas fired system will be very similar in price, as would a dual fuel system.

If you opt for a typical closed loop Ground Source set up, including all of the above, wells and piping your capital cost will run between 25 – 35K. (noted for the next 27 months a 30% tax credit is available, but not considered in this article.)

In this area new construction homes range from 125,000 to 7 million. ??So the lower end is in the 7 – 12 % range. The more reasonable price of 500,000 for a high end spec home in the area results in the 3 – 7% range.

The question of percentages is silly. Builders may like them, but most homeowners will have their eyes glaze over if you bring this up. The goal is to sell homes, not HVAC systems. A home is supposed to be comfortable. Many new ones are not. This link goes into depth on this issue. http://www.healthyheating.com/Thermal_Comfort_Working_Copy/comfort.htm#.Uj9kLr7D_5o

The equation of importance is capital cost to operating cost. Those are best approached with some modeling. I recently completed a model for a 3K sf home with R-25 ICF V 2×4 16OC construction. The operating costs were in the $1,500 range for our utility rates. The HERS Score was 54.

Substituting a GSHP brought the operating costs down by $200 per year and increase the capital costs by 10K. ??The customer opted for the ASHP and ICF over the GSHP and typical construction. He chose where to put his money.

I see a trap in logic using percentages. I provided new construction pricing around here. My cousin in California deals with homes on the bottom range in the neighborhood of 500,000. That makes a hugh difference in the % equation. So try rephrasing the question to get some more accurate results. Leave out the percentages.

Private HERS Rated Homes

During 2013, New Home Builders in the US placed a HERS Rating on over 50% of the new homes built. Builders in most large housing markets have found that a HERS Rated Home sells faster than one that is not Rated.

Is the new home builder the only one that can place a rating on a home?  Actually anyone with an interest in the home can have a HERS Rating completed. The process is the same as when the builder completes the process.

Tonight a new home is on the page listing ‘Actual HERS Rated Homes’ .  This home is one the owner chose to have the HERS Rating completed.  It is being built in Derby, and is listed as Sold Projected. This home was planned to be lower than the standard new home. It is projected with an INDEX of 86.  It will come in lower.  The projected HERS process took into consideration the plan and the levels of insulation and equipment the owner and the builder have decided on.

HERS Rated Homes

HERS Rated Homes

The reports also show how much energy will be used in both heating seasons and cooling seasons by this home.  Several recommendations for cost effective improvements were made.  Several were based on simply lowering the annual utility bills of the home.  When the builder gets pricing for these improvements, the home buyer can make a good decision to proceed with that improvement or not.

Several of the additional insulation recommendations fall into this category. Several of these improvements were based on improving the comfort and Indoor air quality of the home. Again, when the builder has prices in hand the home buyer can make good decisions about these health and safety items. These items include improved equipment, and improved mechanical ventilation over the code required fresh air duct into the furnace.

Yes, there is no code adopted and enforced in the Wichita area requiring insulation in a new home. There is a code item that requires fresh air to be brought in. I have yet to see a new home without provision for a dryer and spot ventilation fans in the bathrooms. The fresh air is needed to compensate for these items.  If it is not provided, these fans will cause fresh air to come in where it can, not where you want.

When think of  a Heating and Air contractor, you have seen them referred to as HVAC Contractors.  The V is for Ventilation.

Remember to ask your Builder for the HERS Rating when you look at a new home. If the builder isn’t Rating his homes, you can obtain a HERS Rating for your favorite model.

Carbon Monoxide and Your Garage

I am studying ‘The Residential Ventilation Handbook’ by Paul Raymer. Mr Raymer has worked with residential ventilation, design, consulting, teaching for over 30 years.

I just reached the Chapter on Garages. I’ve known for several years the potential problems with an attached garage. Two years ago, I did some recommended work in my garage because of these issues. I carefully sealed the wall between the garage and the house, and I installed a mechanical ventilation fan.

lawnChemWhy is the attached garage important to the Indoor Air Quality in your home? OK! What is in your garage? Mostly stuff you don’t want in the house. Like fertilizer, bug spray, weed killer, gas for the lawn mower. Cars, and other vehicles are usually there also.

Mr Raymer includes a table of Carbon Monoxide levels and comments or the potential for harm to people. I knew some of these, and others I did not. Carbon Monoxide is a colorless, odorless gas that is a byproduct of burning fossil fuels, like gasoline, natural gas, or propane. Carbon Monoxide (CO) is measured in parts per million (PPM)

Here are some entries from the table:

1-2 PPM Normal from gas range, traffic etc.

9 PPM Maximum Allowable Level for 8 hour period in any 12 month period. EPA and ASHRAE. Normal after using an unvented gas oven.

15 – 20 PPM Impaired performance in time discrimination and shorted time to angina response

30 PPM UL standard that detectors not sound an alarm unless exposure is continuous for 30 days.

35 PPM Maximum allowable outdoor concentration for any one-hour period within a 12 month period. EPA – ASHRAE

50 PPM Maximum allowable 8 hour work exposure (OSHA)

150 PPM UL Listed detectors must sound full alarm between 10 – 50 minutes of exposure.

500 PPM Car started from cold in garage with door open, and allowed to run for two minutes

800 PPM Dizziness, nausea, and convulsions within 45 minutes.

6400 PPM Death in 10 – 15 minutes

70,000 PPM Typical tailpipe exhaust concentrations after cold start during the first minute the engine runs.

NOTE: After running for 17 minutes, these concentrations finally drop to 2 PPM

tailpipeI think the above table is worth serious consideration from every home owner, every father and every mother.

What Types of Buildings Does a HERS Rater Work On?

I had an question last week.  ‘What types of homes can you put a HERS Rating on?”  A second question came along with it, “What types of buildings can you certify as Energy Star?”

These are great questions!  We usually think of homes as being a house in a subdivision or older neighborhood. It usually houses one family.  These are referred to in the trade as ‘Single Family Homes’.  Not everyone lives in one of these.  There are duplexes, four-plexes and all sorts of high rise apartment houses.  These are referred to as ‘Multi-Family Housing’. There are also buildings that have retail shops or other non-residential areas, with living units on the upper floors. These are referred to as ‘Mixed Occupancy’.

A HERS Rating is applied only to residential units. The ‘Home Energy Rating System’ was developed by the Residential Energy Network, commonly called RESNET. This non-profit organization provides guidelines for training, maintains the standards for the HERS Rating process, certifies the software used to IRS Standards, and finally enforces a Quality Assurance Program on all Ratings issued.

There is an organization that is developing a similar set up for commercial structures called COMNET.

The HERS Rating results in a score on the HERS Index. This score can be used by home buyers, realtors, appraisers, and many others in the property sale transaction. This rating is a private transaction usually between a HERS Rater and the property owner. Many HERS Index Scores are specifically used to market a property.  A HERS Rating may be completed for a new or an existing home. Lenders in some cases are requiring HERS Rating.

The HERS standard does not specify any specific products, methods or other requirements. The resulting Index Score reflects different levels of energy efficiency between rated homes.  A home with a higher score will use more energy than a home with a lower score. The index starts at Zero and goes up.  The highest score I have personally completed was 384.  Most existing homes score between 95 and 150.

A HERS Rating can be completed for single family or multi-family homes. The limitation applies to buildings that are 3 stores or less. In the trade these are referred to as ‘Low Rise Residential buildings.

Energy Star is a Brand that is promoted by the Federal Government since 1992.  It is designed to designate the top 20% of a product line with the most energy efficient features built in.  Every product line has standards for energy use. Specific tests are required on the different products.

Refrigerators are a great example.  A 25 cubic foot refrigerator is only compared to similar size units. A 10 cubic foot unit designed for a smaller apartment is not compared to larger units. there are a large number of refrigerator classes available.

Some products do not have an Energy Star qualifying standard.  Examples here would include clothes dryers and ranges, ovens and cook tops.

Energy Star Homes use a set of mandatory requirements that must be followed and a HERS Rating that must be earned. The requirements are detailed, covering 7 pages of checklists. They require specific energy related items, for example, continuous insulation. They also require things such as flashing of windows and doors for durability. It makes little sense to build an energy efficiency home that would allow water to enter the wall and destroy the insulation.

A maximum HERS Index score  is set, based on the size and number of bedrooms of a home.

Commercial buildings also qualify for an Energy Star Rating. Existing building qualify by reducing energy usage. This process, like most Energy Star certifications, is voluntary and as a HERS Rater and Thermographer, I am qualified to assist with, or to complete.

New commercial buildings qualify for Energy Star, by design and verification of the actual design being present in the completed building.  I can help with this also. Since most of these buildings have architects and other professional engineers involved in the planning, my role is more in the verification process. In the commercial area this process is called Building Commissioning. I would work primarily with the Thermal Enclosure and some of the HVAC issues.

Fresh Air, Your Home, Your Health

It has been said over the years that houses need to breathe.

One of the first times that came up, according to Bill Rose in ‘Water in Buildings’ was during the 1930’s. It had become an argument between the house painters and those pesky Energy Efficiency Folks that were beginning to install insulation in the walls of homes. The 1930’s found our country in the middle of the Great Depression and who could blame folks for trying to save a few bucks! The painters were having problem with their paint peeling.  So they started refusing to paint houses with this new fangled insulation.  If you haven’t heard, insulation in the 1930’s was not new.

John PooleAs an Energy Auditor, I have audited some old houses.  This past year, I did one that was build in 1912 – 100 years old! And a beautiful 1887, two and a half story Victorian. My friend John (on the left)  from Derby, CT works on old houses. He has found insulation in houses that are older than any houses than I’ve worked on. People have lived around Derby CT, for a few years longer than they have Derby, KS. John really likes his old homes.  He would tell you that one built in 1887 is still somewhat new.  His current project is reported to have been built in 1700, or it may have been 1667.  He is still trying to figure that one out. In some of his old homes, he has found original insulation. He is not sure about the R-Value.  That of course would depend on how well it was installed.  What were they using way back then for insulation?  Good question!  Since Derby, CT is near the Atlantic Ocean, they were using Seaweed!  An original all natural insulation! And, if it got wet, it doesn’t mold!

So the painters were slightly behind the times in refusing to paint houses with that new fangled insulation in them. They thought the insulation was stopping air from moving into the house. And that was causing the paint to peel. Actually, the insulation was not stopping the air movement in or out of the house. You can buy furnace filters made of fiberglass as you can find fiberglass insulation.

I think the phrase ‘houses need to breathe’ is somewhat misleading at best. It is the things we all cherish in our homes need fresh clean air.  So somehow, we who operate the building, we call home, need to make provision for a proper amount of fresh air.

hallway Yes, air can come in when you go in and out the door. Maybe the question is, where is your door.  Does it go to a hall way in a high rise apartment building?  How about the attached garage?  What kind of fresh air might that be?  Can you open a window? Yes – many of us do!  Is that enough fresh air? Do you do it every day? Is it really fresh air?

What about your window?  My bathroom window opens. When I do open it, and the dryer is running, the dryer exhaust comes right in?  How about that dryer sheet smell and the moisture and the lint?  Got a swimming pool, or several water features in your yard? What about living near a large pond, lakeside or near a creek or river? The higher humidity in these areas can actually be measured and can get trapped near the soffit of a nearby home. Is that part of your fresh air?

1 Inch HoleIf you don’t make the plan of where and how much fresh air your home brings in, who does make the plan?  My guess is everyone does! Fresh air moves into your home, where it can find a hole. Since most attics are vented, they can provide a hole, then the electrician just drills his one inch hole and puts the half inch wire through it! And you have a hole. The plumber runs a sewer stack up the wall and out the roof. Did he seal around his stack? What about the furnace tech?  He runs a flue up through that attic, or out the rim joist. You can add Larry The Cable Guy, the IT Tech running Cat 5 cable, and the list keeps on going!

You choice now is:

  • Allow the fresh air needed by that which you cherish to come into your home any ol’ way someone lets it!
  • Seal all those accidental unplanned air movement pathways and decide for your self and those you cherish where and how much fresh air to bring in.

A Home Energy Audit — The Value

There is lots of discussion about Home Energy Audits. Utility companies may be providing them to their customers. You can find sources locally and nationally to provide you with one. There are sources online, and several outfits that will sell you a kit to ‘Do It Yourself’!   What should you expect from and audit? Is it worth the expense? Today’s post covers one audit and the results.

A homeowner called wanting to get a handle his old drafty 2 story all brick home.  He thought insulation in the un-insulated walls would help with heat and with the drafts.   He also wanted to know what else might work, and he was interested in how quickly any investment in his home might be recovered with savings from heat or cooling bills.

My visit revealed a nicely maintained home, with minimal energy efficiency beyond the current building practice of 90 years. There had been a few things done in the 1930’s and in the 1980’s that helped.

In discussing the concerns of the family, it was clear they liked their home very much. They had lived there long enough that through re-decorating, gardening and life – it was their home. Comfort issues were not the first concern. There big question was ‘what can we do to save some money?’.  In discussing that, the living room was mentioned as the room that was hot in the summer and cold in the winter.

The audit visit collected data from observation, my tape measure, some pictures.  I looked up in the attic, down in the basement as well as out and around. The furnace, AC and water heater were inspected. The manufacturer had issued a ‘Heat Rise” specification, so testing for that was part of the audit. There was a conventional water heater, and we did a ‘Worst Case Combustion Air Zone” test.

Finally, we would use a Blower Door and an Infrared Camera to measure and locate the potential drafts.

I found some insulation in the attic spaces, and confirmed the homeowners concern of un-insulated walls.

The furnace was within specifications heat rise.  The Worst Case Combustion Air Zone test passed.  The details on these tests and their meaning for a homeowner will be the subject of future posts.

We ran the Blower Door Test.  This test allows us to simulate a 20 mph wind on all 4 sides of the home and the ceiling at the same time. After running the test, standardizing the numbers for temperature difference, and accuracy; the house tested with a Natural Air Exchange at 1.3 times per hour.  The recommend rate without any type of added ventilation is 0.35 times per hour.

With the data collected, a computer model of the energy use in this house was created.  This showed insulating the basement would return the cost in about 5 years. Sealing the leaks revealed by the blower door test would pay off in about 10 years. The leaks were in the basement near the 1st floor; between 1st and 2nd floors and at the ceiling of 2nd floor or 1st floor where it was attic above.

Increasing the R-15 to R-60 in the attic would take 11 years to pay off. Improving a wall on the 2nd floor between a hall and the attic about 20 years to pay off.  And the exterior walls to be insulated would take about 99 years to pay off.  These periods all use the current utility rates, with no price inflation.

The homeowners contacted several contractors to obtain actual prices on the various improvements.  They chose to do some air sealing, insulate the basement walls, the attic, and the wall between the hall and the attic, and to install a new furnace and air conditioner.

After the work was complete, I returned to do a verification audit of the work. The new Blower Door test showed the planned 25% reduction was reached.  The HVAC installation included a new return line to the living room, which has reduced the temperature difference, so the room is no longer shut off on warm days in the summer or cold days in the winter.

BeforeBelow are two before and after infrared images. They show the 2nd floor hallway from the same point. The before picture was taken in February about 11:30 am.  This hallway is on the east side of the roof peak.

 

AfterThe after picture is taken in June about 5:00 pm. The February outside temperature was 46 degrees; the June outside temperature was 98 degrees. Both images were taken with the blower door moving air from inside the house to the outside; simulating a windy day.

 

 

The center of the clipped ceiling (diagonal slope) measures  78 degrees  in the before picture. In the after picture it measures 97 degrees.  So the outside temperature of 45 degrees before  work translated to a 33 degree increase passed through the deteriorated insulation.  After work 98 degree outdoor temperature translates to a 0 degree increase passed through the air sealed and new insulation.

If you look closely the air sealing could have been improved. The planned 25% decrease was accomplished.  It would have been nice to exceed the plan.

What good are the results?  The increased insulation is allowing the AC to work a whole lot less!  If the home had a 33 degree increase in June as it did in February – summer in Wichita would have been miserable in that home.  Also when the new furnace was installed the contractor running the new return to the living room, found a old return in the room that had no duct work. So he hooked up to that return grill for less than planned.  The living room is now comfortable.

Will your Home Energy Audit achieve these kind of results?  Perhaps it will!  If you would like to find out – give us a call.  We would be happy to discuss in more detail how your Home Energy Audit would work.