EnergySaving

Cut Down Cooling Costs

2008-05-26T13:40:40Z

Q: With summer coming how can I hold down my electric bill without sweating for three months?

A: Start with understanding what compromises your cooling costs. First is load second is delivered efficiency of equipment.

Load comprises anything that creates or allows heat into a living area. Common items under load include

1. Attic insulation
2. Wall insulation
3. Window Quality
4. Window shading, including indoor blinds depth of eaves
5. Internal gains- refrigerator, cooking, hot showers, clothes washing and drying, people
6. Infiltration
7. Incandescent lighting
8. Attic Ventilation

Delivered Efficiency

1. Seer- the government rating for air conditioners
2. Air flow- without correct airflow no air conditioner will run near efficiency
3. Unsealed ducts- could also be under load
4. Clean condesor and evaperator coils.

These are the major factors of your cooling utility costs, improving any will reduce costs. Where to start depends on your budget. An air conditioning tuneup is about $100, simple sealing with caulk and foam can lead to improvements in cost and comfort. Weatherstripping, sealing an attic access, or sealing can lights and supply registers all provide great bang-for-the-buck. Other low cost options include well shaded drapes or curtains, preventing solar gain will provide huge benefits. Installing florescent light bulbs will cut down on heat. Grilling outside helps as well as drying clothes on a line. I have suggested the clothes line to my wife and she called me an idiot so maybe not the best plan. Wall insulation is much harder to improve in an existing home and usually isn't an option unless siding is also being replaced. Attic insulation is much easier to handle even for the greenest handy man. I would avoid attic insulation until all chases and wiring runs are sealed and any duct work in an attic is sized properly, balanced and sealed.
If your budget is a little higher and you are considering new equipment there is a lot to know, I can't hit everything but here a few things to know. Duct sealing is not a joke , there are plenty of times I've recommended sealing ducts as opposed to a new air conditioner just to see a raised eyebrow. Leaky ductwork is usually the biggest culprit in an uncomfortable expensive to cool home. By the way if your tech pulls out duct tape call someone else. If your ac tech tells you the duct is too small and restrictive then you have found a well trained tech. Sealing undersized duct will cause more problems than it fixes, mostly equipment failure and a loss of capacity. If your now satisfied with your duct work and are replacing your ac make sure your bid includes a new evaperator coil and confirmation of airflow, I can't state enough that incorrect airflow will be a problem. Just a few side notes on ac's, 13 seer is now the minimum efficiency but there are still 10 seers hanging around that should be avoided. There is a current phase out of r-22 freon in place in favor of r-410a or puron. Puron is Bryant/Carriers name for R-410a and should be the refrigerant in your new equipment install.

Home Energy Savings Tips for a $100

2008-05-21T18:40:27Z

A recent commentor asked what repairs could be made for less than $100. I'm going to assume you've already had an a/c tuneup.
$100 isn't a lot but you can make a dent.

Basement - With a few tubes of caulk, some expanding foam and a step stool or ladder start in your basement at any corner looking for cracks or penetrations. Plumbing pipes, or conduit/romex are likely to have gaps. For openings less the a 1/4" caulk will seal well, any larger and the foam will be better. Look for gaps in the framing, between the sill plate and rim joist or where 2 sections of rim meet.

Once youv'e made it around the basement and hit all penetrations and cracks start looking for "chases" any area where duct, conduit or venting goes to the attic. If you have a second story and one furnace most likely duct runs from the basement to the attic. An installer will cut the sub floor out large enough to run the duct through, if this gap is left open a tremendous amount of air can end up in the attic. If the gaps are small go ahead and caulk if they are larger do not try and foam it will fall out and end up in your hair or clothes. Trust me it doesn't wash off or out very easily. If the gap is already stuffed with fiberglass pull it out, it is useless for stopping airflow. If the gaps are large you might have to pick up some flat tin stock from the home center. The tin will cut easily with a $10 pair of snips. Cut the tin to shape around the duct leaving enough excess to nail to the subfloor with roofing nails. It doesn't have to be pretty or even one piece. After all you tin is installed caulk every edge of tin.

Living Areas - Working in a finished areas of the house will need a little DIY skill. In a low traffic area of the house pull a section of trim off to see how the window was sealed. Not very long ago it was acceptable to fill the gap between the window and framing with fiberglass. If that's what you have the glass need to be pulled out and replaced with caulk or non-expanding foam if you use the wrong foam it will be a mess at best. If your windows are in need of resealing your doors probably need it as well. This repair will probably be the most noticeable in terms of comfort and drafts, well worth it.
This second tip should not even be attempted unless you are qualified to work with household electricity. All electrical boxes on outside walls should have foam between the box and the sheeting.

To check turn off the power to a switch or outlet and pull it out of the box, if it is a plastic box like the one in the photo a small screwdriver through the tabs will let you see if there is foam. If there isn't any foam through the tabs will fill behind the box. Yes you will have to hit every one. More home energy saving can be gained through can light and boot sealing. All in all I can't see this hitting $75.

What in the world is mechanical ventilation?

2008-05-15T17:31:43Z

Last week I explained the benefits of mechanical ventilation assuming everyone understood what I was talking about, a common mistake from the trades. Several e-mails have asked for clarification of mechanical ventilation

.

Exhaust ventilation- Removes the contaminant at it's source, like a bath fan or kitchen exhaust hood. While this qualifies as mechanical ventilation it is hardly optimal. Exhaust only leads to unbalanced pressures, drafts and potentialy unsafe backdrafting.

Supply Ventilation- Provides a means of introducing fresh air into the home to replace exhausted air and help with dilution of home contaminants. Traditionally a duct is ran from the cold air return of your HVAC system to the outside metered by a barometric damper or an electronic damper that opens and closes based on preset conditions. Of the two I prefer the electronic version. By bringing the air through the return we can condition and filter the air before it is introduced into the living area. Coupled with quality bath and kitchen exhaust fans this setup is effective and should be your minimum standard.

HRV/ERV- Stands for heat recovery ventilator and energy recovery ventilator. An HRV/ERV is a balanced exhaust system that runs the exhaust and intake air through a heat exchanger, pulling the heat out of our conditioned air before we send it outside. An ERV is the same setup that also pulls out humidity making it a great fit for hot humid areas. HRV's can be installed stand alone or tied into the duct system. Based on conditions set by your installer the unit will exhaust and replace the same volume of air with reduced heating/cooling load due to the heat exchanger. Another fantastic idea that I saw involves a remote mounted bath fan that pulls air from several bathrooms that ties into the ERV. Instead of sending that warm steamy air outside it is ran through the ERV.
Below is a generic diagram of a typical ERV.

Mechanical ventilation = better air, money saving, safety and a more comfortable home

2008-05-11T12:32:34Z

Anyone who has spent money on tightening up an existing home or spent extra for energy upgrades for a new home will be irritated by the concept of mechanical ventilation. Understandably it doesn't make sense to make a home more airtight then add a way for more outdoor air to come in, but having your home ventilate properly is critical. Why?

Indoor Air Quality- Indoor Air Quality or IAQ has become a buzzword in the HVAC industry. Sometimes buzzwords come about from marketing or misinformation but here there is a legitimate need, as homes are tightening up pollutants are trapped in the home. Older homes are ventilated naturally, but at the cost of comfort and efficiency. Indoor air starts as outdoor air and becomes "dirtier" from pollutants in the home, ventilation removes dirty air and dilutes the existing air.

Common sources.
Excess moisture. High humidity can lead to condensation which can lead to mold.
Chemicals. Paint thinners, cleaning products, insecticides such.
Building Products. Most newer products contain chemicals from their production like glues or formaldehydes.
Pets. Dirt dust and dander
Smoke. Candles smoking or even deep frying let off contaminates that hinder breathing.

Energy Savings- The issue is air is coming in whether you want it to or not, any home exhausts a certain amount of air through bath fans, kitchen exhaust hoods, water heaters, older furnaces or one pipe furnaces, stack effect from leaky can lights, hvac boots, attic hatches or clothes dryers. All the air that leaves will be replaced through cracks, outlet boxes, open doors, or far worse a back drafting water heater flue. Since that air is coming in our goal should be to control it. Mechanical ventilation allows us to bring it into the duct system where it will be conditioned and filtered before coming into the living area. Some types of equipment have heat exchangers that pull the heat out of air before it is exhausted.

Comfort. By controlling where the air come in we reduce drafts and cold spots.

Safety. We know how as our homes vent or exhaust air the air needs to be replaced, this is called negative pressure. The safety concern comes when a home has a fire place or b-vent water heater that begins back drafting from the negative pressure. If air is being introduced through the b-vent when the water heater fires the exhaust gases will spill from the draft diverter allowing co2 into the house. mechanical ventilation reduces this condition. Regardless of your situation you must have co2 detectors in your home.

Yard and Lawn Care

2008-05-03T13:20:03Z

I get a kick out of most things related to home ownership and repair. I subscribe to quite a few blogs that are home related and some are pretty good, one I've been reading for about 5 months, Life and Lawns, has been impressive. Plenty of posts, so topics stay current to the season, that are well written withadvice that is easy to understand and follow. If you care about your lawns appearance it's worth reading.

Cost effectiveness of energy retrofits

2008-05-03T08:01:58Z

Recently I've had several people ask how to determine which home repairs are best for saving money. The question is easy to answer on paper but is a little tricky in real life. We are going to assume the decision
is based soley on dollars not architecture or environment or other factors that are legitimate.

The first way to asess a repair is payback period. The calculation is simply, if a repair or retrofit is a $1000 and saves a $100 a year then the payback is 10 years and the annual return is 10%. Lifecycle costing is a little more sophisticated method of measuring cost effectiveness. The theory is that when contemplating any action, one should compare the lifecycle cost of taking the action against not taking the action. For example a standard hvac system will use $1200 a year for the next 25 years costing $30,000 if no action is taken. A new system will cost $5000 and use only $600 a year or $15,000 over 25 years. The new system's initial cost of $5000 plus its fuel usage of $15,000 equals $20,000 so it would be prudent to replace the system. The ext step is the BCR or benefit/cost ratio. In the above example take the savings ($10,000) divided by the cost ($5,000) to arrive at a savings-to-investment ratio of 2. An sir of 2 means the retrofit will pay for itself twice during the life cycle. Just for clarification the numbers above are made up just to show the ideas, I know a fair amount of factors were left out of the example. I will get more specific about individual retrofits later.

Some Great Blogs

2008-05-03T08:07:00Z

I know this isn't home related so please forgive. These are some of the sites that I have in my reader. I thought some peope would enjoy the information and the feeds.

Subscribe to OnHomeComfort

Subscribe to NWIReviews

Subscribe to InfectedByBugs

Subscribe to JohnCowdotCom

Subscribe to TylerCruz

Subscribe to ProBlogger

Subscribe to ShoeMoney

Subscribe to JohnChowDotCom

Technorati Profile

Poor policy

2008-05-03T08:07:50Z

Rumors always flow heavy at supply houses the latest that has been gaining credibilty involves an hvac contractor advertising an $89 air conditioning tuneup. The issue comes after the work is ordered and performed and the tech hands the homeowner an invoice with a $20 "gas surcharge" added. I can't imagine a worse message to send to a customer, and if I was the homeowner I would refuse to pay the "gas surcharge".
Thankfully most people inside the trades are condemning this practice. I would go so far as to suggest not using a contractor that pulled this stunt.

Nice Review

2008-04-26T08:39:18Z

On Home Comfort recieved a verynice review from NWI Reviews. They are a sight reviewing a fair amount of subjects, most related to Northwest Indiana. If your from the region area go ahead and check them out.

Building Smart: Fiberglass vs Cellulose

2008-05-03T09:24:21Z

I've made it clear I'm not a huge fan of fiberglass insulation for a new home. My objection stems from how often I've seen poorly installed fiberglass insulation. Now I've come across a study performed by the University of Colorado School of Architecture. The idea was to test real world performance of cellulose against firberglass batts.

Two similar structures were built one with r-19 fiberglass insulation in the walls and r-30 fiberglass insulation in the attic, the other had r-19 cellulose insulation in the walls and r-30 cellulose insulation in the attic. The cellulose insulated building was seven degrees warmer after a nine hour heat loss test. More importantly, after three weeks of monitoring building performance the cellulose insulated building used 26.4% less energy than the fiberglass structure. The conclusion drawn was that the cellulose building performed 38% better than the fiberglass insulated building. Keep in mind both buildings had the same stated r-value. Keep a look out for effective r-value instead.

Should I have an air conditioner maintenance agreement?

2008-05-03T09:25:16Z

This question was e-mailed by a reader.

I think a maintenance agreement or energy savings agreement is a great idea. Obviously it would only be worthwhile if it include a quality air conditioning tune up. A few considerations in choosing your HVAC contractor.
1. Are they providing a proper tune up?
2. Are they a full service company?
3. Do they have a seperate service department? You don't want to wait all summer for an understaffed company.
4. Do they offer a 15% discount if you should need service outside of the maintenance agreement.
5. Are their techs uniformed in lettered trucks?
6. Are they considerate in explaining what they found?
7. Is your home left clean free of footprints?
8. Are you offered priority service for breakdowns?

Spring cleaning should include an air conditioning tune up.

2008-05-03T09:27:01Z

As a home owner you should be aware of what is involved in an air conditioning tuneup. If you read any home maintenance articles this spring, most will encourage an A/C tuneup; some will even claim 25% savings. Predicting savings without knowing what type of tuneup received is a little silly. Encouraging a tune up without explaining the difference between an average tuneup and a high quality tuneup is a shame and expensive.

Most tuneups claim to adjust, check, reset, or modify back to factory settings. What does that mean? It implies that when the service tech is done your system will be good as new. What it really means is that the ad is not very specific; tough to figure if you got your moneys worth.

First a little insight, the tuneup is the basic advertising model for most HVAC companies. The idea being they sell you a $59 tuneup hoping you're so impressed with the work that it will lead to a new furnace install when the time comes. Any HVAC company will happily service a customer for years just for a chance at landing the new equipment job. If that logic is stretched out the more tuneups the more future jobs so why not drop the tuneup price? Just one problem as price drops, pressure to do more tuneups per tech increases and the quality of the tuneup suffers.

What should a quality tuneup include?

1. Measure airflow of system, absolutely critical for capacity and efficiency. Most air conditioners require 400 cfm of air to operate at capacity. There are three ways to measure airflow

A. Static pressure measurement. This is the most accurate method providing the blower wheel is cleaned.

B. A duct traverse. This involves drilling a series of holes in your return drop to measure air flow with a wand style meter.

C. Tru-flow air meter. A measuring device installed in the filter slot. Some techs believe its accuracy drops with poor duct design.

D. Temperature drop across the system is not an accurate measurement of air flow, while temp drop is important in diagnosing

it will not accurately determine air flow

2. Clean the condenser. The out door unit should be sprayed with a heavy foaming cleanser that soaks for ten to fifteen minutes before rinsing.

3. Measure indoor and outdoor conditions. Indoor wet bulb, indoor dry bulb and out door dry bulb should all be measured. A qualified tech will have the tools for this. After all measurements are taken the tech should plot them on a sliding chart that will determine required super heat. Super Heat is an HVAC mesurement that sets proper refrigerant charge.

4. Adjust refrigerant charge, as important as airflow. After airflow is set, the condenser is cleaned and super heat is determined, the tech can hook up his gauges and set the refrigerant charge.

5. Other useful measurments.

A. Temperature drop across coil should be 18-22 degrees, this is universal.

B. Temperature drop across outdoor unit. The tech will know this depending on unit.

C. Amp draw of compressor:b this will depend on size of unit.

For any company to do this work correctly it will cost more than $59. Tell the dispatcher what work you want done and understand that it will cost more. If it costs twice as much as a junk tuneup it's worth it for your comfort and wallet. Some companies will only pull and clean blower wheels on a Time and Materials basis and thats okay. Now you can talk to your tech with out worrying about being bluffed into a bad job.

Energy saving takes a little common sense

2008-05-03T09:35:26Z

See how a simple mistake can cost you 10-12% on utility bills

I went to a home in Munster IN to look at the hvac system. The homeowner was concerned his utility bills were higher than than needed. When I looked at the furnace in the attic I noticed the filter access cover was missing. The homeowner said he didn't recall ever seeing a cover. He audibly scoffed when I told him replacing the cover would save him more than any of the other measures he was considering. A missing cover in an attic allows the furnace blower to draw cold attic air into the duct work. After mixing with the house air brought through the returns the overall temp entering the heat exchanger is considerably lower making the furnace run longer than it should. I guessed he kind of believed me but didn't really want me to do any testing. Without testing I can only give some estimates but it will still make the point.

The upstairs furnace blower should have been set at 1000 cfm. The open filter cabinet could allow 350 cfm through depending on the static pressure of the duct work, to be safe I'll use only 200 cfm.
The house is 70 degrees and the attic is 35 degrees.

So what happens? The thermostat calls for heating, starting the furnace. An 80% furnace should have a 55 degree temp rise. That just means for 70 degree return air the supply should be 125 degrees. But we have only 800 cfm of 70 degree air and 200 cfm of 35 degree air, yielding 1000 cfm of 63 degree air and supply air of 118 degrees.

What does that mean? First that seven degree loss equates to 12% of capacity and about 11% loss in efficiency, and thats at 35 degrees the colder it gets the worse the effect. Losing that much capacity and efficiency will be clearly felt in comfort and seen on high utility bills. I didnt even touch on the effects during air conditioning season
I made some assumptions in the calculations:

1. The furnace was tuned correctly.
2. The insulation around the attic duct was correctly installed.
3. The furnace was truly 80% efficient.

Overlooking seemingly small items can add up quickly in cost and comfort.

Attic Ventilation is critical for a comfortable home

2008-05-03T09:36:24Z

Most home owners are unaware that proper attic ventilation is required by most county codes. Here is a website http://www.savenrg.com/code.htm. that describes these codes in detail.

Why do I need proper attic ventilation?

Attics can reach a stifling 165 degrees in the Midwest summers and even higher temperatures in the south. Ventilation exhausts this hot air to the outside and serves to keep the home more comfortable. Also, ventilation helps to protect other parts of the structure such as roof framing and sheeting.

I‘ve found that standard passive ventilation like ridge vents and punched aluminum soffit vents do not work well. I’ve cut into enough roofs and felt the hot air rush out.

What about insulation?
Insulation prevents the conduction of heat from warmer to cooler areas. The thicker the insulation, the longer it takes to equalize the temperature on both sides. In a 150 degree attic with a 70 degree second floor, the insulation will be somewhere between this.At night as the attic begins to cool, the insulation will hold the heat and therefore will even be hotter that the attic air.

Ductwork in attic?

If you have a 2 story house, odds are you have ductwork somewhere in your attic buried beneath the insulation. If your air conditioning is properly tuned, there will be a 20 degree drop against the A-coil. Meaning if the air returning to the blower compartment is 72 degrees then the air above the coil should be 52. Just a side note: having a 20 degree drop doesn’t mean your system is dialed in, but not having the drop confirms it. Losing just 5 degrees of heat from the plenum (top of furnace) to the upstairs vents cuts your effective capacity 25%. The hotter the attic means the larger amount of temperature loss, leaving the insulation even hotter. A 12 degree temperature loss is not uncommon, meaning a loss of 60% of capacity.

Here is a typical scenario: The home empties out in the morning and the thermostat raises up to 80 degrees. As it gets warmer throughout the day the attic gets hotter and the insulation gets even more so. At 430pm, the thermostat is set to drop the temperature to 70 degrees. It is 77 degrees in the house, meaning that the discharge temperature at the coil is 57 degrees. And because your a/c is probably not tuned correctly, that 57 degree air might be 61 degrees when it hits the hot duct in the attic and could be 71 degrees at the vent, leaving your poor a/c to run constantly in a futile attempt to cool the house.

Though its cooling off outside, your left fuming inside because your house won’t cool off for several more hours.

What’s the Solution?

The solution is better ventilation, specifically, mechanical ventilation. Solar powered fans do not work. They simply don’t move enough air around, possibly cutting the temperature by 5 degrees, but it won’t be enough for you to notice.

A quality fan that is installed correctly should have at least a 1500 cfm rating. The fan should be installed in a gable wall preferably with a vent in an opposite wall. Thermostat controls in the attic will turn on the fan whenever the attic is above 90 degrees and the attic is hotter than the outside air. Look carefully at the picture: if the fan is installed like this it will not work and will probably curse me for leading you astray. The vent needs to be sealed completely with aluminum, plywood, ductboard, etc around the fan ducting to be effective.

Radiant Barrier Information

2008-05-03T09:37:04Z

This is a picture of installed radiant barrier thermal chips in an attic. So much of the information available on radiant barriers and products is misleading or even incorrect. This is a project that takes moderate skill but is very effective.
If your even remotely curious about radiant barriers check out the link before you undertake any project

HEPA filters

2008-03-30T11:01:02Z

Found a nice article about some of the benefits of HEPA filtration. HEPA is just an acronym for high efficiency particulate arrestor. The picture article shows a room size unit. My preference is for a whole home HEPA bypass filter mounted on the duct work. The duct mounted units have genrally moved considerably more air across the filter meaning more air is cleaned over the same amount of time. A new unit should run about $800 installed. energy saving tips

Leaky can light fix

2008-05-03T09:37:49Z

This is just a cutaway of a typical can installation. In an earlier tip we discussed sealing the can to the drywall from underneath. While that helps infiltration around the can it doesnt address through the can or the poor insulating value of the can. The picture above is typical of most can light installs. It is easy to see how much heat could leave through this setup. One builder I know threw buckets over the cans before the insulators came through. I've never fely like I had a great solution until recently. I was talking to a friend whos been in the trades for years, and his fix was to install a 12"x12"x12" duct board box over the light and caulked to the drywall. This is a simple fix. Duct board boxes can be made up by your local hvac contractor for around $20. The walls of the box are an inch thick so there is plenty of surface to caulk to the drywall. If your light is next to a cieling joist the duct board is easy to notch with a utility knife, just make sure you caulk between the notch and the joist. For less than $25 each light you have stopped the air leakage and significantly improved the r-value. Thanks Dave for a great idea.

Higher end filters worth the cost?

2008-05-03T08:18:07Z

When I'm in Home Depot or Menards, I walk down the heating aisle to look at how different products are marketed. Almost always someone has an "allergen"(these are the more expensive filters promoting clean air) air filter in their cart. Almost always I ask them about why they picked that filter, and always, my embarrassed wife vanishes. Most responses involve wanting better Indoor Air Quality (IAQ) or not minding the cost if it's a better filter.

I wonder how the responses would change if they new that allergen filter was costing 7-8% of the furnace or ac's efficiency and maybe capacity. First, the furnace filter is not designed or installed for IAQ. It is installed to protect the equipment. Dirt and dust travel through the ducts, and any dirt that settles on the fan blades, heat exchanger, in the blower motor, or the wet ac coil will reduce efficiency and equipment lifespan. Furnace manufacturers design their equipment, mainly the blower motor, to provide a certain cfm against a certain static pressure.

To explain that I need to touch on duct design a little bit. When a duct system is designed and sized several factors are taken into account.

1. CFM. Cubic feet per minute. This is a measure of volume, similar to gallons, of air. A very specific amount of air must travel through the furnace based on its btu input. Too much variation of this cfm will change the equipment performance.

2. The resistance of the duct. A duct's resistance to airflow is measured in static pressure.

3. A fan chart. A manufacturer's fan chart is available for any furnace a designer might spec. That chart lists the amount of air that can be delivered against a duct systems resistance or static pressure. The fan chart allows for a filter pressure of .1 inches of water column. If that makes no sense don't worry you will never need to know or remember it. The .1 rating is about 20% of the total resistance.

What does any of that mean? It means your homes ducts should have been designed to move 1200 cfm (for a 3 ton ac) with a static pressure in the duct of .5 inches of water column. If tested, it will almost certainly be underperforming. Most houses are running with the SP (static pressure) higher than design standards. Meaning, the airflow is delivered at the edge of the systems limits and any change in resistance can reduce the desired airflow. An hvac system can never perform at full efficiency or capacity without correct airflow.

"Allergen" filters would be any that advertise high"merv", better IAQ, or just cleaner air. They will also cost $5-6 as opposed to less than a dollar for fiberglass. I will agree that the more expensive filters will stop more dust. The filter accomplishes this by being much more restrictive than your fan can overcome. Their static pressures may be as much as 3 times as figured in the design stage. A system that is already
underdesigned can easily lose 7-8% of capacity with the addition of a restrictive filter. I'm not in the field anymore so I dont test as much as I used to but every summer during a hot streak it was not uncommon to find one house that would be at half capacity, causing an expensive and uncomfortable house.

If you are concerned about indoor air quality you will have a much more effective and efficient system with a bypass HEPA, EAC or PHI CELL air purifier that can be installed by your HVAC contractor. You will be money ahead.

Builder Series #3

2008-05-03T09:38:44Z

I dont know how many builders offer options regarding framing but I'd like to touch on it a little bit and hopefully get some more input. Framing can usually be described as 2x4 or 2x6 at 16" or 24" on center. This simply describes the depth of the stud, 3 1/2 inches for 2x4 and 5 1/2 inches for 2x6, and the spacing of the studs. In Lake County I see a mix of 2x4 and 2x6 but I rarely see 24" oc. That isnt a scientific position just an observation.

For our discussion this affects how much insulation is installed in the exterior walls. Obviously a 2x6 wall is deeper than a 2x4 which allows the insulation, fiberglass or blown cellulose, r-value to be about 19 instead of 14. The stud spacing affects the ratio of insulation sq footage to framing sq footage. A 28' wall with 16" on center will have about 22 studs, not counting cripples or window studs, the same wall at 24" on center has about 14 studs. That is a difference of 8 sq ft of insulation per wall a significant amount. I'm begginning to believe that the 2x6 at 24" oc is a better way. There was an article written several years ago that claimed the 2x6 system not only was more efficient but more cost effective with regard to material. I'm tearing my office apart trying to find the article, if any one knows of it please let me know.

The most common wall insulation choices in northwest Indiana are fiberglass, blown cellulose and spray in foam. Fiberglass batts and blown cellulose have about the same rated r-value. The difference comes in the installation, any product installed poorly will not operate effectivly. For insulation to work effectively it has to completely fill the cavity, behind outlets, around penetrations and around electrical conduit. Any gaps or voids significantly reduce the effectivness. In my opinion cellulose is a much better choice than batts, cellulose is blown in and around and behind anything in the wall cavity, more often than not fiberglass batts are not installed correctly. My desire was to just give information and not make declarations but on this matter I strongly believe that blown cellulose should be the minimum standard for most homes.
Spray foam is usually a 2 part chemical sprayed into the wall cavity that expands to fill about half of the area, the rest is filled by a batt or cellulose. The best part of the foam is its ability to seal the cavity from the outside. While most foams have a higher per inch r-value the best part in my opinion is the ability to seal. Unfortunately My system designing software doesnt have the subtelty to see the variations between foam and cellulose so at this time I cant give any hints at payback time for the higher cost. This seems like enough for this post but there are some more insulation topics to cover and I will hit them later in the series

Build smart series #1

2008-05-03T09:40:00Z

If you’re getting ready to start, or have already started the process of building your new home, you are probaly finding that there are hundreds of decisions to be made. My goal here is to help with some of the questions you have by providing as much common sense information as I can regarding the comfort and efficiency of a new home. I sincerely believe that you can do some very easy things to drastically increase your home efficiency.
Let’s take a second and talk about the different types of homebuilders active in Lake and Porter counties in Northwest Indiana.
Production builders
Production builders will generally have fewer options available than custom or semi cuctom builders. This is to be expected given their business model. Successful production builders are so because they have figured out how to build their particular models quickly and efficiently allowing them to be very competitive cost wise. Any options that are not typically handled by their staff can cause delays and cost over runs. If you are working with a production builder and sense they don’t want to deal with a lot of changes, you are probably correct. This is not an indictment of this business model, you are definitely getting the benefit of buying some scale and economies of scale.
Custom Home Builder
Even in this niche there are numerous customer experience models. Most of the truly custom home builders are former trades that wanted to build for themselves. This process will be much more involved in the design and selections. You are going to get the exact house you want, but you will be paying for one of a kind. This builder is much more willing to try new types of technologies as long as you’re willing to pay learning curve.
Custom home builders in Northwest Indiana are much more prone to look at zoning, to look at hybrid heat, geothermal, insulation increases for comfort and efficiency. This isn’t to say that Production home builders won’t allow these types of changes, but they will probably want to use their own existing contractors, some of these contractors may have limited options available.
In general custom homes are going to cost more, but allow a much more intense customer experience.
U are the Builder
Lastly, due to increase in home costs, and flexibility of schedules some people will choose to build and contract their own homes. If you are interested in this kind of process you can hire someone to “consult” with you to get better pricing and plans, but you are the contractor. You can have anything you want, and the universe of home comfort options is huge, but you pay the learning curve.
Tags: energy efficiency, home builder, home comfort, new construction, nothwest indianaPosted in New Home Series Edit No Comments »