EnergySaving
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EnergySaving
Cut Down Cooling Costs
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.
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
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
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.
$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.
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.
What in the world is mechanical ventilation?
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.
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
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.
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
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
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.
is based soley on dollars not architecture or environment or other factors that are legitimate.
Some Great Blogs
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.
Poor policy
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.
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
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
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.
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.