Category Archives: Air Sealing

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

 

 

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.

Earth Day 2014

Everyone seems to have something good to accomplish on Earth Day this year.  Twitter and Facebook have had regular comments all day. Energy Star had a Tweet Up going online with people from all over the country.  GE donated some LED lamps for a give away.  So to get in the spirit, here is what I  accomplished.

image001Wichita Habitat for Humanity builds Energy Star new homes.  One of the requirements is to limit duct leakage, by strictly following Wichita City Code and all manufacturers instructions for materials.  The professional standard established by the Air Conditioning Contractors nationwide is 6% of system air flow. Energy Star requires 6 cfm (or less) of leakage with a duct pressure test for each 100 square feet of floor area.  This home tested at 50% of the Energy Star Requirement.  The system tested at 5% of system airflow.  Great work!  The mechanical contractor on this house is Cook’s HVAC of Wichita.

BDThis afternoon, I did a Blower Door Test. This test measures the energy loss due to infiltration.  This again, was new construction and the first HERS Rated Home in Wichita for the season. Wichita / Sedgwick County have not adopted the Energy code. If they were enforcing the 2009 version, this home would have exceeded the requirement by almost 50%. It is 20% above the requirement for an Energy Star New home.  Great Work! This shout out goes to a number of contractors.

1 Inch HoleAir Sealing has many pieces.  Framers, electricians, plumbers can all cause many problems for this test.  So when they cooperate to help achieve the end result, it is a good thing. Fibrous insulation (Rockwood, Fiberglas, Cellulose), by itself does not effect infiltration. Air will move through all of them. The insulators must install the insulation correctly. They must caulk many places. I observed much of this during my pre-drywall inspection.

IMG_6793I am sure Wade will pipe in here for a comment and a shout out for these subcontractors.  Wade Wilkinson is principal of GJ Gardner Homes of Wichita.  This home will be their entry in the Wichita Area Builders Association’s Spring Parade of Homes. You can read my Post on the WABA Parade of Homes

 

IMG_6788

 

Verifying good workmanship by builders and contractors is a great part of being a HERS Rater.  What did you do for Earth Day?

Water Pipes Freezing and Cold Weather is Predicted — What should I do?

When the recent cold snap with below Zero temperatures approached, I had several calls about the potential for freezing pipes and what a homeowner could do.  This blog post has compiled all those answers and some other information for easy access.

Things you should know about your water pipes.

Location:  Where are they?  Interior walls?  Exterior walls?  Typical plumbing runs pipes through the wall to the cabinet under (or behind) the sink, shower or tub.

If it is an interior wall, you have less chance of those pipes freezing, then if they are in an exterior wall.

Location:  Where do the pipes enter your home?  Into a basement?  Into the crawl space? Under your mobile home?

This can be a problem area.

The weather forecast says “Your Water Pipes Might Freeze Tonight! Knowing where your pipes are enables you to take some simple preventative action.

Open the cabinet doors by the pipes on exterior walls.  This allows the warmer air from the room into the cabinet area.  Check to see and remove any cleaners etc that a child or pet might get into.

Open a cold water faucet at the sink and let it drip slightly.  Moving water does not freeze. It doesn’t need to move a lot, just a little.  If you do this you may need to replace the faucet washer later. Small price compared to frozen pipes.

Don’t lower your thermostat temperature.  Bypass any setbacks on the thermostat. The amount of energy will be a minimal cost compared to frozen pipes.

Don’t leave home in the winter for any length of time *and* turn the heat down.

If your water supply comes in through a vented crawl space, close the vents.  Check to see that insulated pipes have intact insulation and that it is not wet.  Wet insulation is worse than no insulation. This also applies to mobile homes.

If your water supply comes in to a basement that is not heated, check as if it were a crawl space.

You get up in the morning and there is no cold water at one sink.

First try the other faucets to see if this is just at the one sink, or perhaps where the pipes come in.

Leave each frozen faucet open.  As the ice begins to melt, the water will begin to move and that is good.  Moving water will melt the ice faster.

How you identify the area where the pipe is frozen may vary, you will find it in an area that feels cold, and it seems logical to you that no heat is getting there.

You will have to search for the frozen section(s) of pipe. You can do this with your hand. If you touch the pipe and it is really cold,  you may be close or there.  Normally, water coming from a pipe that is under ground, will be between 50 and 55 degrees F. You will feel the difference with a frozen section or close to frozen section of pipe at 32 degrees.  You can also use a contact thermometer.

If you find no water at all faucets, then your frozen section is probably at a point of entry to the home. Older homes, prior to the 1940’s, that were built before running water was brought into the home, will have many varied places to look. If you have lived there very long, you probably already know. Otherwise, it will be in a basement or crawl space, or perhaps an exterior wall.  If you live in a home that is built on a concrete slab, your odds of a frozen entry pipe happening are minimal.

To Thaw the frozen section. Use heat!

Use a blower dryer, a heat lamp, some type of portable heater. You can use a towel soaked in very hot water, and wrung out well.

Do *not* use any type of open flame.  Pipes are almost always close to parts of the home that burn, and that is not a good thing.

Second, stay with your heat source and the frozen pipe.  If the pipe starts to leak during the process, you need to know so you can shut off the water.

When you get the pipe section thawed, and you have no breaks or leaks, great! If you get any type of leaking, get it fixed.

Prevention for the next cold snap.

You should follow the simple preventative steps listed earlier.

For a more permanent solution, you need to create a situation where the pipe section that froze is kept warmer. That means you add heat or insulation and stop cold air movement.

Pipe insulation from the big box or the hardware store could help.  Buy the correct size, it comes molded for 1/2, 3/4 and larger pipes.  This is a foam that you can easily compress.  So, fasten it snugly, but not tightly.  It should fit more like a nice sweater on your arm instead of a tight rubber band.  Since it is squeezable, it is open cell foam and will allow air movement through it. So I would wrap it with something to stop the wind. Tape would be easy, but you could use something rigid, like small pieces of plywood. For tape, you could use packing tape, or duck tape.

Depending on the location of the pipe section, some rigid foam, blue or pink board type, might work better. Typically this would be a pipe near an exterior wall, with room to put the insulation between the pipe and the wall.  You can fasten it to the wall.

Most of these will also benefit, and some instances will require additional heat.  So opening a cabinet door is something you might have to continue. Modifying any type of duct work is not recommended for directing heat at this type of problem.

This leaves those section in an unheated basement or a crawlspace.

You could add a heat tape.  Make sure you have easy access to this to turn it off after the cold snap and to turn it back on for the next one.  If you don’t, you will probably leave it on all winter and that is expensive. You also need to carefully check the sizing of any extension cord. If in doubt, hire an electrician to add an outlet, so an extension cord is not needed. Adding this type of fix is also something to keep your eye on and check regularly. It is a Fire Hazard.  I would not recommend a used heat tape.  Buy a new on and replace it annually, until you get a more permanent and safe resolution.

Permanent and Safe Solutions

These require some thought and planning. They may take a contractor to implement. You may find through the planning process, other problems that will be fixed.

Give me a call, if you have frozen pipes and want a permanent solution. I can develop a solution for you. Since I don’t sell the products you might use, I can come up with a solution that works for you! Not one that moves my merchandise.

What percentage of residential new construction cost do you think a high efficiency HVAC system should be? 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’.

If 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. If you are building with 2x4s use 24 inch centers, ladder connections for interior walls and 2 stud corners. Fill the extra room with insulation not wood. NAHB pioneered this in the 1970’s because of the high cost of framing material. ??You can install R-13 batts in those 2×4 walls, or you can use a blown in system. If you get the correct density and verify it, you can get R-15. You can choose a hybrid system with a 1 inch flash of CC SPF and blown in FG or Wet Sprayed Cellulose. R-17 or 18. ??Insulate the basement walls, crawl space walls and the above ground walls. ??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.

What Tools do you carry in your Tool kit?

I have all sorts of small items in mine; a list would include flashlight,  screwdriver, hammer, tape measures, wrenches, my blower door and infrared imaging camera.  Plus a bunch of flashlights. Yep!  A bunch of flashlights.  I like those everywhere, usually two at a time.flashlights

What kind of tools do you carry?

furnaceAn HVAC Tech might have the first part of my list, and a set of pressure gauges and thermometers instead of my specialized equipment.  Yes, I don’t really need his specialized equipment.

An Install Tech for an Insulation Company would probably have the general stuff and some specialized tools like an insulation blower, staple guns, and an air compressor.

Yes, the work you do requires certain tools. Most tools are fairly general and found in almost everyone’s tool kit, some are specialized to the work we do.

Now that I have pointed out the obvious, everyone maybe wondering why I’m thinking about tools and home performance. So lets connect the dots a little.

First, what happens if you get to the job and you can’t find a screw driver?  It has happened to me more than once!  I just hate that!  How many knife blades have we broken on our pocket knives when we find ourselves in that position?  We still have a job to do and the wrong tool takes longer, sometimes with banged knuckles.

What happens when the products or services we provide to our customers, can perhaps meet their need, like the blade on a pocket knife, but do not meet the need like a screwdriver?  That is the position many in the building performance are find themselves in.  They have a customer that is uncomfortable in their own home or a business with uncomfortable employees and customers.  How does the management design a solution for their techs to implement and thus satisfy their customer, making them comfortable again.  As a business, we each try to provide the solution to the customer from our stock.  That is how we get paid. You don’t pay the mechanic that fixes your car, when the plumbing needs to be fixed.  You pay the plumber, after the drain works again.

So you have a room that is Hot in the Summer and Cold in the winter?  Who do you call and what solution do the problem do you implement?Insulation Blown

If you call a Heating / Cooling contractor, they have equipment on the shelf, probably not insulation. So you will have a proposal to change your equipment for bigger units or perhaps to add a unit. The proposal will certainly involve equipment.  After all, if your mid size car gets you to the store, a larger car will get you there with more comfort.  Would you expect your HVAC contractor to recommend insulation?

What is the actual answer to to your comfort situation? Larger equipment with more punch or some insulation?  What if your solution does not involve either equipment or insulation?

Now we are back to the tools of our Trades!  What tools do you have?  Equipment, Insulation, Air Sealing, Windows?  The solutions you provide must involve the tools of your trade. That is why a savvy homeowner might consult with more than one contractor.  That is a great argument for savvy contractors to partner with contractors and others that work on changing the energy use in your home or business. Why should a good contractor limit themselves to providing only part of the solution.

Air SealingThis is happening in many areas of the country.  Contractors are partnering with others in their area to build home performance teams. There are contractors in Wichita that are moving in this direction.  I think that is great!

Deciding on the measures that will solve your comfort concerns, while bringing down your energy costs, involves a team that includes all of the contractors and a Energy Specialist that does not have a product on the shelf to sell you. The ability to recommend, without having a financial interest in the products, has been valued by many home owners. An Audit by Efficient Energy Savers, provides you with the independence in evaluation, and recommendations needed to get the answer you are actually looking for.

 

Some Results from Energy Improvements

When doing a Home Energy Audit, I always tell people that what I find is not good or bad. I tell them that what I can recommend for improvement depends on  the cost of their Utility Bills.

If you have a water leak, we all know that paying the price to a plumber to fix it, will cost us when the plumber comes. We also know if we don’t fix it, we can pay the water company that amount over 1 or 2 or 6 months. How long depends on the amount of the leak and the cost from the Utility for your water. And then we still have to pay the plumber. so we make a choice.

Blowing insulation into the walls!

Blowing insulation into the walls!

Wendy stuffing insulation into the hopper!

Wendy stuffing insulation into the hopper!

Some choices are easy, for improving the efficiency of a home.  Most homes with a tank type hot water heater inside the home, in a balanced or cooling climate (south of the Kansas / Oklahoma border) will benefit from installing a water heater insulating blanket.  They cost about $25.00 and typical savings just north of the above line can run from 6 – 8 dollars per year. So at $6 bucks a year, the blanket pays for itself in about 4 years. And most people can afford $25.00.

Other choices are somewhat tougher.  Instead of $25.00 to invest in the improvement, cost can run $2,000 to insulate a basement.  If you spend time down there, you know it is a little colder in both the winter (brrr) and the summer (nice), then upstairs.  Again, using some Wichita area numbers a homeowner could save in the area of $350 per year. Each house is different, so I am using some averages from various audits. If you apply this  savings over 6 years, the insulation is paid for and you still save the money. The hitch? It is harder to come up with $2,000 instead of $25.00.

In 2011, I had an Energy Efficiency Project approved under the Efficiency Kansas Program. They loaned some cost, I paid some costs and we added some (a bunch) of insulation, air sealing to cut the infiltration, replaced a 18 year old furnace and air conditioner. I also added an Energy Recovery Ventilator.

Wade in the attic! Fixing a dropped soffit in the kitchen! You can see the 3:12 pitch on my roof.

Wade in the attic! Fixing a dropped soffit in the kitchen! You can see the 3:12 pitch on my roof.

My payment over the 15 year loan is 870 per year, due monthly on my Utility Bill.  So the question is, how did I do with saving some money?  I have been tracking my Natural Gas and Electric billings, with numbers going back to 2009. When I changed HVAC systems, I went to an electric Heat Pump with a gas furnace for back up or emergency heat. As a result, my gas bill dropped and the electric bill, which includes the loan repayment amount is higher than I can remember.

To account for the change, I had to do something with the natural gas, billed in MCF (1,000 cubic feet) and the electricity, billed in KWH (kilowatt-hours).  I decided to convert the gas usage to KWH for ease in comparing before and after.  I also wanted to be able to compare usage against the weather.  Some summers are hotter than others and some winters are warmer then others.

The National Weather Service tracks our weather very well.  You can get an F-6 Report from most airports around the country. In Wichita, we have a choice of 3.  There is Mid-Continent, the primary commercial airport; there is Jabara Airport, a smaller facility that specializes in private airplanes.  And we have McConnell AFB.  All have weather observations and reporting.

The F6 NOAA Report for March, 2011 at ICT. The 2 columns between the red lines show the HDD and CDD.

The F6 NOAA Report for March, 2011 at ICT. The 2 columns between the red lines show the HDD and CDD.

How did I compare the before and after?   Excel works great for prototyping number crunching and charting the results.  I collected my data on usage, cost and Degree Days from the Weather Service.  I built two charts. First one covering January 2009 through present. After looking at this chart, I built another showing January 2011 through present.

The charts show three (3) lines. The Blue Line represents Heating Intensity by month.  I took Heating Degree days, multiplying by 5.  The Red Line represents Cooling Intensity by month. I took Cooling Degree days, multiplying by 3.5.  The Green line represents Energy, show in KWH.  I converted my gas usage to KWH by ” MCF x 293 “. Then I added the KWH from Electric and Gas to chart the Green Line.4 years

2009              2010                     2011                  2012                 2013

If you look at the top peaks of the Blue Line – you see the cold months. Imagine a level line averaging those tops. Somewhere between 4000 and 5000 on the Y-Axis. Look at the Red Line Peaks – you see the hot months. Imagine a level line on the Average of those peaks, just a little over the 2000 on the Y-Axis.

Now look at the Green Line, it goes up in the winter, and summer, down in the spring and the fall. This line doesn’t really run level on the peaks. If you pick about 6500 on the Y Axis in 2009 and 2500 in 2013, the line slopes down.  The Red vertical line shows when the improvements were made. This chart shows 3 years prior to the date of improvements and 1 year after.

The Chart below just shows one year before and 1 year after.  So the horizontal spreads out a little. I think the point is made in either chart.  The improvements require less energy to be purchased.

How much less in dollars, instead of Energy Usage? I’m saving my 870 annual repayment amount plus enough to repay myself over 15 years for what I kicked in.  And a little extra.

2 years

2011                                    2012                                   2013

Some one will ask why did I adjust the HDD and CDD numbers.  I did it to match the scales on the charts.  I first set it up with direct numbers. When you looked at the chart you could not make out any significant ups or downs to compare. So I reworked the numbers with multipliers, to make the charted numbers line up better.

In September, 2011 the chart shows 155 HDD, 591 CDD, the energy usage in KWH is 2261.  In September, 2012 the chart shows 0 HDD, 960 CDD with 1217 KWH used. Using the same Y-axis scale required some changes. So I used a multiplier to move from direct Degree Days for Heating and Cooling to an intensity measure for heating and cooling.

Thanks for following along.  I will make another post with more of this story.