HVAC – Cleaning Your Condensate Drain

April 25, 2017

You probably read my article on “Is your Air Conditioner running Efficiently“, there are a lot of good tips in that post as we near the air conditioning season. In this post I want to highlight the condensate drain (another one of those items that gets little respect or notice until it’s not working properly).

Looking at the picture with the blue box knife you will see a piece of 3/4 copper with all but about 1/4 inch opening left. This is what I found today as I replaced a condensate drain. I would have never figured this!! As with many HVAC installations, units may be changed out every 10 years or so, but how often is the condensate drain replaced or inspected? Granted, this will not impede the unit from making cold air, but it may leave an ugly damp spot on the ceiling or floor (depending on the location of the HVAC).  As it can back up and overflow.

 

HOW DOES A CONDENSATE DRAIN WORK: Lets first start by understanding  what the condensate drain does. In the process of the cooling the house, the evaporator coil inside the air handler unit (located in a closet, attic or basement) operates at a temperature that creates condensation on the cooling coil. The collected water from this process  has to drain off. The water drips off the evaporator and is  expelled through a drain pipe. Based on gravity and slope, the water is either released outside the house or into the sanitary drain pipes. This drain tube must stay clean of debris, otherwise it can back up and cause water to drain into the house damaging sheetrock and possibly the building structure. They only drain when the unit is running in AC mode. Visually seeing water dripping is not a good enough inspection as it could still be backed up.

HOW TO INSPECT THE CONDENSATE DRAIN:

Visually inspect the condensate drain for all the parts mentioned in this picture. Pouring a vinegar in the VENT and the pan will allow you to look for leaks and the rate of flow. Both locations should drain in a few seconds.

  • VENT: Should be open and clear.
  • PAN DRAIN: Should be open and clear. Should exit out of the house where visible. If you see water dripping from this drain pipe (at its exit), the primary condensate drain is probably stopped up.
  • DRAIN PAN: Resides under the HVAC unit and should be clear of debris and free of water. Rusted pans should be replaced. Collected water in this pan is an indication there may be a drain flow stoppage of the primary drain.
  • PRIMARY & PAN DRAIN: Both should have a slight downward slope to its destination. This will ensure the water can flow freely out of the house.

HOW TO CLEAN A CONDENSATE DRAIN: If the drain has never been cleaned, it would be best to use a Wet/Dry vacuum cleaner to attach to the pipe (at the end, outside the house) to suck out all the debris. Seal the vacuum cleaner hose to the drain pipe (furthest from the HVAC). Run the vacuum for about 5-10 minutes. In really bad cases, you may need to pour some vinegar down the drain to pull the gunk through the pipe while the vacuum is running. If necessary, you may need to repeat it until it shows to be running free and clear.Once you know it is clear pour a a gallon of vinegar down the drain once a year. That should keep it in good shape.

 

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HVAC Ducts Reinsulating vs. Replacing

December 13, 2016

duct_sealing1If you have read any of my last articles on HVAC ducts you recognize that, like the HVAC units, the duct network is a system as well. In the past I was an advocate of reinsulating the existing ducts over replacing them because of the cost. However, I am changing my tune as I continue to see more and more duct systems that were either so poorly installed from the get go or they have been patched, damaged or added to (incorrectly)  they weren’t worth saving.

On my most recent project, I found the return air plenum was sucking return air right off the dirt floor in the crawl space. Some people might say “it just smells like an old house”; trust me, even an old house shouldn’t smell musty if the system is in good condition.

TOSHIBA Exif JPEG

For the most part, properly installed ridged system can be superior, but if not, they stink. One of the biggest problems with ridged duct systems are: They are ridged! Just like the biggest problem with flexible ducts are; they are flexible!  As with any house construction there are lots of obstructions that have to be dealt with. The flexible ducts are great for these applications as they can be easily routed around structural beams. However, all turns and bends should be gradual and smooth. No kinks or sharp turns.

One of the most disappointing things I see in residential construction is what I call “the lack of trade respect”. Think of it like fighting siblings, the older brother is always going to pick on the younger brother, just cause he can.  Time and time again, I find shoddy work that is caused by a sibling trade.  In a  recent remodel project, we found that the HVAC contractor purposely removed several supporting beams because: they were in his way. In turn, it was left that way and didn’t show up until the roof was replaced some 40 years later. The roofers couldn’t re-deck the roof because of 6 split rafters, in other words, the roof was caving in. Admittedly, the workers are long gone but the negative effect of their work lives own.  The rafters had to be rebuilt and purlins had to be replaced. Though our investigation, it was obvious that the HVAC tech removed them so he could have a straight path for his ridged duct.  Negatively impact the integrity of the house was trumped by his laziness or willingness to cut corners. As with most attic or crawl space work, there is no one checking their work.

newhvac-duct

New Duct system installed using flexible ducting

Its not uncommon to find a 50 year old house that has had new HVAC units installed multiple times but the ducting is still 50 years old. Granted, when an HVAC unit fails to work, the problem is the units not the ducting. As the homeowner it is easy to just have the units replaced and leave the ducting as is since the new ducting can be as expensive as the unit itself. Unfortunately you can easily be giving up some of the  efficiency gained by replacing the units. To learn more about “Improving the Efficiency of Your Duct System“, I have attached a link to a paper written for the US Department of Energy by Brookhaven National Laboratory. After reading the article and you realize it is time to replace the ducting, look to schedule the work in off-peak months. You will probably get a little better deal and a lot better job.


Is Your Air Conditioner Running Efficiently?

August 11, 2015

AC unit Here in the Southwestern part of the country air conditioning is a requirement. With temperatures running above 100 degree’s for weeks at a time, these systems can struggle to perform as necessary to keep you and your family cool. Besides filters, there are a few other things that are worth mentioning. If you think you may have a problem, it will probably be showing up in your electric bill as either you or your system is having to compensate for its inability to perform as required.  Canvas your neighbors about their electricity usage as a comparison. Talk to folks that have simular houses and life styles for a good comparison. Square footage, thermostat settings and occupancy times are all important. Differences of more than 20% can be a clue there may be an issue. Also, use energy numbers or kwh as listed on the electric bill not the actual dollars spent. Here in Texas, the electricity is deregulated and there could be 2 to 5 cents of difference in kwh per hour charges.

If your system has operated properly in the past, these inspection and preventative maintenance items will ensure optium performance.  However, if your system has never worked properly or struggeled to keep the house cool, you may have design or service conditions that may warrant a call to a professional. Either way, by inspecting and maintaining the obvious you are  isolating the issue allowing the trained technician more time to fix the problem less time to find it.

Inspection and Maintenance Items:

  • Clean air filters: Replace the air filter 2 to 4 times a year. See my complete article for details.  Heating/Cooling Air Filters.
  • Air Returns:Keep these vents clean from dust debris and any obstruction. Depending on the design, the return air vent(s) may be close to the floor or in the ceiling. If the air return is near the floor, remove the metal grid and use a vacuum cleaner to remove all the dust and debris. If you have an air filter located here, replace it as necessary. In some cases you may have a filter here as well as at the unit. If so, this filter should be replaced on the same schedule as your normal filter.
  • Room Temperature: A well designed central air conditioning system should provide balanced air flow and temperatures of no more than about 3 degrees in difference from one room to the next. Large windows and doors will impact that number to some degree.
  • Air Flow: With air registers in each room, the air must circulate from the room to the return air location. For this reason, the air must be able to exit the room with the door closed. Either the door will (should) be undercut or there may be a pass-through return vent into a hallway or another room. If doors slam themselves shut (when the system is running), you may have a return air issue. TIP: If you recently added new carpet to your house, and you are now having air conditioning problems, the new carpet may not be adequately allowing the air to return under the doors. 
  • System Temperature Differential: This test is similar to checking your blood pressure as variables can effect the results. Most professionals set the thermostat low enough to require the system to run constantly (8 to 10 degrees below ambient) for at least 30 minutes (run it longer if you can). Use a digital thermostat to validate the air temperature exiting the register. Do not go by the temperature of the register itself. Its the air temperature you need. Do the same at the make-up or input air. You should have a temperature differential of 14 to 20 degrees in difference.   Too high or too low is a symptom of a larger problem. High numbers indicates a 1) dirty filter, 2) improper/inadequate duct-work, 3) a fan not spinning fast enough or undersized.  A low number indicates 1) refrigerant loss, 2) a dirty coil, 3) overworked compressor, 4)over-sized fan, or 5) deficient/blocked  return air system. Check the obvious, then contact an HVAC specialist.
  • HVAC drainWater Pan and Condensate Drains: In the process of the cooling the house, the evaporator coil inside the air handler unit (located in a closet, attic or basement) can pull humidity out of the house envelope. In doing so, that water collected by the system has to be expelled. By design, a drain is connected to the unit and released outside. This drain tube must stay clean of debris, otherwise it can back up and cause water to drain into the house causing damage to Sheetrock and overtime to the building structure. They don’t drain all the time so just visually seeing water dripping is not a good enough inspection. Once you locate the drain, use a Wet/Dry vacuum cleaner to attach to the pipe (at the end, outside the house). Seal it as best as possible and run the vacuum for a couple of minutes. This should pull any bugs, lint, dust or debris out of the pipe. This is a better method than pouring water through the system, and a lot less messy. Perform this function at least once a year.
  • Outdoor Compressor: Ensure plant material is clear of the compressor (18″ to 2′), remove leaves, grass, vines by hand. Use your water hose to spray down the coils to remove lint dust and dirt. This is probably one of the most important quick solution to a system that is under performing.
  • 100_0529Outdoor Compressor Connections: There should be two copper pipes and one maybe two electrical conduits. The larger of the two (suction pipe) copper pipes  should be properly insulated (all the way to the air handler/evaporator coils in the house. This pipe is delivering the cold freon used to cool the house. The longer it can stay cold, the better. Also look at the electrical connections to ensure they are sealed (sealtite  type conduit) and secure. There will also be a small low voltage wire  that may or may not be in a conduit, make sure it is not cut chafed or deteriorated.
  • Air Ducts: This item deserves an article on its own. Independent studies have shown up to 35% loss in cooling capacity due to poor duct insulation, leaky ducts, leaking air vents and duct splicing.  Inspect for air leaks  throughout the entire system. All of these components that make up the delivery system should be sealed with the highest degree.  Use Aluminum faced tape or mastic paint rated for UL 181 applications to seal any holes. DO NOT USE FABRIC BASED “DUCT” TAPE. TIP: If you are considering replacing your HVAC system look seriously at replacing the duct work as well. Poorly insulated ducts can reduce your SEER rating by 50%.
  • Set Back Thermostat: If you don’t have one, you need one. This is one of the most effective ways in managing your heating and air conditioning requirements and costs. Basically, you program it to change the temperature automatically to meet your lifestyle needs by adjusting the temperature for periods when the house is not occupied. Regarding the maintenance? Most are battery equipped and you should change it once a year.
  • Attic Insulation: Inadequate attic insulation can also effect the performance of your system. Use this US Gov link to determine if you have enough insulation for your region. Use a straight edge or yard stick to measure the insulation in various places. Avoid compacting it or stepping on it any more than you have to. Use a rake to re-spread and  fluff the insulation.

Key Inspection Points Action Items:

  1. Replace air filters
  2. Inspect and clean all air grills
  3. Clean and inspect outdoor compressor unit
  4. Clean condensate drain
  5. Inspect ducts for leaks
  6. Change battery in thermostat
  7. Check level of attic insulation

Heating/Cooling-Air Filters

August 13, 2011

 Indoor Air quality is between 2 to 5 times more polluted than the outdoor air (US Environmental Protection Agency, September 1999)

I am invoking the 90/10 rule on this subject. Good basic air filtration will reduce dust and keep your HVAC equipment in good working order. For the other 10%, specialized filtering may be required to obtain hospital grade filtration, reduce allergies or conditions that have caused your house to be considered sick. If you have concerns of that level you may try some expensive HEPA type filters or consult an air quality specialist.

aifilter

MERV 1-4

To help us understand filter performance,  the standards body ASHRA created the 52.2 standard for rating replacement air filters. MERV or Minimum Efficiency Rating Value defines filtration performance with a 1-16 scale with 16 being the most efficient. However, “efficient” in this context is about  the amount of  particulate collected through the filter at the cost of reduced air flow. Using  a filter with the highest rating will require more service as it may 1) clog more quickly, 2) require more regular replacements, 3) be more expensive, and 4) add undue wear to HVAC components, 5) cause your system to over work, in-turn use more electricity.  So, if you do not have specialized filtering needs, finding a happy medium between efficiency and air flow is the prime objective.

 MERV Rating 1-4: Typically a very thin membrane made of fiberglass strands. This filter will picks up the big stuff and will reduce particulate to your system but will not provide any real air quality value.  The efficiency rating is <20%.  A MERV 1-4 filter can be purchased for a around $1 each.

Pleated MERV8

MERV 5-8

MERV Rating 5-8:  Typically a pleated cloth type membrane is more efficient and should meet most normal needs. With an efficiency rating of >20 but <50% these pleated panel type filter will provide adequate filtration as well as keep your equipment in good shape. They are about $3 each.

MERV Rating 9-14: Used in commercial or industrial applications based on their ability to remove certain smells and oders are becoming more popular for the home market. Assuming you can find the size you are looking for it will cost you $8 or more. When you get past a MERV11 they can be more difficult to find and expensive.  See the ASHRA MERV table for specific filtering requirements.

TIP: When you jump from a MERV7 to a 11, the price triples. The biggest difference is the amount of efficiency.  Based on the NAHB (National Association of Home Builders) Green Building Program they recommend a MERV 9 or better.  ASHRA 62.2P  also recognizes proper air filter efficiency at 60% or 3 microns ( MERV 9).

When you visit your home center they will probably limit your selection to 3 or 4.

  1. The cheap fiberglass stran filter, MERV 1-4
  2. A large selection of MERV 5-7. They may even be packaged in quantity priced at about $3 each or a little less in quantity.
  3. A MERV 9-11. Fewer sizes but still a reasonable selection. About $7.95 each. If you are struggling with allergies, something greater than a 10 may help.
  4. Maybe a HEPA (MERV14-15) or another high-end disposable filter at $15 to $100. These may be recommended to you for specific algeric conditions.
electrostatic-air-filter

Lifetime Electrostatic

Reusable or Life-time filters: Unfortunately there is not a standardized rating method for these type filters and I have failed to find enough independent data to support their use. Depending on who you listen to, an electrostatic filter could be similar to a MERV 4 on the low end and a MERV12 on the high. An electrostatic filter can cost between $60 to $300. If you are using a MERV 9 or better you may consider a reusable electrostatic type filter. You will have to be the judge as to it meeting your needs. HomeownerBOB has no recommendation here but I have read more positive comments about the BOAIR brand. If it works for you, it will  pay for itself in less than 2 years and you won’t be throwing filters in the trash.  The biggest advantages of  electrostatic filter are 1) they can be washed out and reused, 2) their efficiency rating is in the 90% range and 3) the airflow is excellent and does not deteriorate at the same rate as a pleated filter. Once you wash it, it is completely restored. Many times electrostatic filters come with a lifetime warranty.

Hybrid pleated/electrostatic charged filters:  MERV does not rate this type filter either. The manufacturers market this filter by having the attributes of both pleated and electrostatic filters, but at $17, its still a disposable filter.

Many professional will encourage you to change filters on a monthly basis and depending on where you live, that may be the right thing to do. HomeownerBOB recommends that you replace your filter some where between 2 to 4 times a year. You will need to be  the judge on the conditions that may warrant more or less frequent changes.

Reasons to change/clean your filter more frequently may include:

  • Continued use of heating or air conditioning throughout the year
  • Living on or near a busy street, highway, airports or rail road track
  • Living in a dry/arid part of the country
  • Living in an area with a low percentage of annual rain and or high winds (Texas, New Mexico, California, etc)
  • Living on rural property with a lot of exposed dirt
  • Living on an unpaved road

As I said in the beginning of this article, these filter recommendations are based on the larger body of population that does not have health related conditions. There are many more filters, filtering systems,  filtering strategy (cascading) and air exchange studies that can be used to solve air quality issues.

Recomendation:

It should be pretty obvious, unless you have special needs, or live in a very dusty enviornment, the MERV 5-7 should work fine.

Key Inspection Points and Action Items:

  1. Change, or clean your HVAC filter at least 2 to 4 times per year.

Attic Insulation – Do You Have Enough?

July 30, 2011

rockwool1Proper attic insulation can make a drastic impact on your utility bills. Any home over 5 years old should have the attic insulation evaluated as settling insulation and higher summer temperatures  can degrade its ability to protect your home from the summer heat.

7 reasons to be concerned about the condition of your attic insulation.

  1. High utility bills.
  2. Its been more than 5 years since the house was built.
  3. You have lived in the house for more than 10 years and never evaluated it.
  4. Some thermal insulation materials settle more than others.
  5. Increasing summer temperatures require more insulation.
  6. Recent contractor activity in the attic  (i.e. telephone, CATV, Security, HVAC). These workers can matt down the insulation while performing their job.
  7. Rodent infiltration. These buggers will easily pack down the insulation to get to various points of interest.

Acceptable attic insulation 10 years ago is not the same as it is today. In fact, in just 3 years, my region has been increased from an acceptable value of R31 to R38.

The Inspection:

  • Determine how much insulation is required. Use this Insulation Chart to determine how much is enough.
  • Enter the attic with great care. Attic entrances may be through a door or attic stair case or possibly a hatch in the closet. WARNING: You must keep your feet/body on the wood joists (beams) as stepping on the sheet rock will cause damage, and possibly cause you to fall through the ceiling.
  • With a flashlight and yard stick: Randomly check the depth of the material. Ensure the measuring device (yard stick) touches the sheet rock and measure to top edge of the insulation material. Try not to crush the insulation while performing the inspection.
  • Determine the type of insulation.  Different material have different R values.

rockwool3If you can see the ceiling joist as in this picture, you  probably do not have enough insulation.  Typical ceiling joists can range from 2 X4’s, 2X6’s to 2X10’s.  For instances, if you have 2X6 beams with loose fill rock wool, you would have a R value of 16.5 (3.0X5.5″=16.5). Newer houses typically have larger beams. Determine the material type as this will help in figuring out how much insulation to add. Use the chart below to calculate the R value of the existing insulation. TIP: If you find you have enough insulation in areas that have not been disturbed, but you find areas matted down due to activity or construction work. Use a soft plastic rake to fluff it back up.

Insulation Table

Common Types of Insulation in Residential Attics

  • batt insulationFiberglass: Comes in batts, blankets, and loose fill, either pink, white or yellow in color. Fibrous in nature and can leave you with microscopic splinters. TIP: Before working with fiberglass insulation, spread a heavy coat of baby powder over any exposed skin, this will fill your pores briefly while working with the material.
  • rockwool2Rock Wool (or Mineral Wool):Loose fill used aggressively prior to 1970. Usually brown or dark gray in color.
  • Cellulose:Loose fill made of recycled paper. Blue or gray in color. With close inspection you will find small pieces 100_0550of newspapers. The product is treated with a fire-retardant solution for safety.
  • Combination:This is not a type, but you may find a combination of two or all three types. Previous owners may have added insulation over the life of the house. This is not a problem, but you should determine how many inches of each type to calculate the value of the existing insulation.

By now, you should know, how much insulation you have vs. what you need. Assuming you need to add insulation, HomeownerBOB highly recommends hiring a professional for this task even though the home centers will provide you tools to perform the work. Once you determine what type of new insulation you prefer, you can easily bid shop the work over the phone.  The professional will need to know 1) square footage of the house, 2) type of insulation material you would like, 3) how many inches to apply.

So how do you determine what type of insulation to use? Read my article on “The Choices“.


How Long Will They Last? Household Materials and Appliances

January 23, 2010

 Ever wondered how long household appliance should last? How about that fiberglass tub you are thinking about buying instead of a cast iron one?

With proper maintenance and inspection these items should provide adequate service to you and your household.

This list is courtesy of the U.S Dept of Housing and Urban Development. Printed in 2000.

Life Expectancy of Household Components
Appliances Life in years
Compactors 10
Dishwashers 10
Dryers 14
Disposal 10
Freezers, compact 12
Freezers, standard 16
Microwave ovens 11
Electric ranges 17
Gas ranges 19
Gas ovens 14
Refrigerators, compact 14
Refrigerators, standard 17
Washers, automatic and compact 13
Exhaust fans 20
Source: Appliance Statistical Review, April 1990
Bathrooms Life in years
Cast iron bathtubs 50
Fiberglass bathtub and showers 10-15
Shower doors, average quality 25
Toilets 50
Sources: Neil Kelly Designers, Thompson House of Kitchens and Bath
Cabinetry Life in years
Kitchen cabinets 15-20
Medicine cabinets and bath vanities 20
Sources: Kitchen Cabinet Manufacturers Association, Neil Kelly Designers
Closet systems Life in years
Closet shelves Lifetime
Countertops Life in years
Laminate 10-15
Ceramic tile, high-grade installation Lifetime
Wood/butcher block 20+
Granite 20+
Sources: AFPAssociates of Western Plastics, Ceramic Tile Institute of America
Doors Life in years
Screen 25-50
Interior, hollow core Less than 30
Interior, solid core 30-lifetime
Exterior, protected overhang 80-100
Exterior, unprotected and exposed 25-30
Folding 30-lifetime
Garage doors 20-50
Garage door opener 10
Sources: Wayne Dalton Corporation, National Wood Window and Door Association, Raynor Garage Doors
Electrical Life in years
Copper wiring, copper plated, copper clad aluminum, and bare copper 100+
Armored cable (BX) Lifetime
Conduit Lifetime
Source: Jesse Aronstein, Engineering Consultant
Finishes used for waterproofing Life in years
Paint, plaster, and stucco 3-5
Sealer, silicone, and waxes 1-5
Source: Brick Institute of America Floors
Floors Life in years
Oak or pine Lifetime
Slate flagstone Lifetime
Vinyl sheet or tile 20-30
Terrazzo Lifetime
Carpeting (depends on installation, amount of traffic, and quality of carpet) 11
Marble (depends on installation, thickness of marble, and amount of traffic) Lifetime+
Sources: Carpet and Rug Institute, Congoleum Corporation, Hardwood Plywood Manufacturers Association, Marble Institute, National Terrazzo and Mosaic Association, National Wood Flooring Association, Resilient Floor Covering Institute
Footings and foundation Life in years
Poured footings and foundations 200
Concrete block 100
Cement 50
Waterproofing, bituminous coating 10
Termite proofing (may have shorter life in damp climates) 5
Source: WR Grace and Company
Heating, ventilation and air conditioning (HVAC) Life in years
Central air conditioning unit (newer units should last longer) 15
Window unit 10
Air conditioner compressor 15
Humidifier 8
Electric water heater 14
Gas water heater (depends on type of water heater lining and quality of water) 11-13
Forced air furnaces, heat pump 15
Rooftop air conditioners 15
Boilers, hot water or steam (depends on quality of water) 30
Furnaces, gas- or oil-fired 18
Unit heaters, gas or electric 13
Radiant heaters, electric 10
Radiant heaters, hot water or steam 25
Baseboard systems 20
Diffusers, grilles, and registers 27
Induction and fan coil units 20
Dampers 20
Centrifugal fans 25
Axial fans 20
Ventilating roof-mounted fans 20
DX, water, and steam coils 20
Electric coils 15
Heat Exchangers, shell-and-tube 24
Molded insulation 20
Pumps, sump and well 10
Burners 21
Sources: Air Conditioning and Refrigeration Institute, Air Conditioning, Heating, and Refrigeration News, Air Movement and Control Association, American Gas Association, American Society of Gas Engineers, American Society of Heating, Refrigeration and Air-Conditioning Engineers, Inc., Safe Aire Incorporated
Home security appliances Life in years
Intrusion systems 14
Smoke detectors 12
Smoke/fire/intrusion systems 10
Insulation Life in years
For foundations, roofs, ceilings, walls, and floors Lifetime
Sources: Insulation Contractors Association of America, North American Insulation Manufacturers Association
Landscaping Life in years
Wooden decks 15
Brick and concrete patios 24
Tennis courts 10
Concrete walks 24
Gravel walks 4
Asphalt driveways 10
Swimming pools 18
Sprinkler systems 12
Fences 12
Sources: Associated Landscape Contractors of America, Irrigation Association
Masonry Life in years
Chimney, fireplace, and brick veneer Lifetime
Brick and stone walls 100+
Stucco Lifetime
Sources: Brick Institute of America, Architectural Components, National Association of Brick Distributors, National Stone Association
Millwork Life in years
Stairs, trim 50-100
Disappearing stairs 30-40
Paints and stains Life in years
Exterior paint on wood, brick, and aluminum 7-10
Interior wall paint (depends on the acrylic content) 5-10
Interior trim and door paint 5-10
Wallpaper 7
Sources: Finnaren and Haley, Glidden Company, The Wall Paper
Plumbing Life in years
Waste piping, cast iron 75-100
Sinks, enamel steel 5-10
Sinks, enamel cast iron 25-30
Sinks, china 25-30
Faucets, low quality 13-15
Faucets, high quality 15-20
Sources: American Concrete Pipe Association, Cast Iron Soil and Pipe Institute, Neil Kelly Designers, Thompson House of Kitchens and Baths
Roofing Life in years
Asphalt and wood shingles and shakes 15-30
Tile (depends on quality of tile and climate) 50
Slate (depends on grade) 50-100
Sheet metal (depends on gauge of metal and quality of fastening and application) 20-50+
Built-up roofing, asphalt 12-25
Built-up roofing, coal and tar 12-30
Asphalt composition shingle 15-30
Asphalt overlag 25-35
Source: National Roofing Contractors Association
Rough structure Life in years
Basement floor systems Lifetime
Framing, exterior and interior walls Lifetime
Source: NAHB Research Foundation
Shutters Life in years
Wood, interior Lifetime
Wood, exterior (depends on weather conditions) 4-5
Vinyl plastic, exterior 7-8
Aluminum, interior 35-50
Aluminum, exterior 3-5
Sources: A.C. Shutters, Inc., Alcoa Building Products, American Heritage Shutters
Siding Life in years
Gutters and downspouts 30
Siding, wood (depends on maintenance) 10-100
Siding, steel 50-Lifetime
Siding, aluminum 20-50
Siding, vinyl 50
Sources: Alcoa Building Products, Alside, Inc., Vinyl Siding Institute
Walls and window treatments Life in years
Drywall and plaster 30-70
Ceramic tile, high grade installation Lifetime
Sources: Association of Wall and Ceiling Industries International, Ceramic Tile Institute of America
Windows Life in years
Window glazing 20
Wood casement 20-50
Aluminum and vinyl casement 20-30
Screen 25-50
Sources: Best Built Products, Optimum Window Manufacturing, Safety Glazing Certification Council, Screen Manufacturers Association

Re Insulating HVAC Ducts

December 1, 2009

The US EPA reports leaking ducts reduce overall HVAC efficiency by 20% accounting for a loss of over $140 per year due to these leaks.

 As mentioned in earlier articles, HVAC ductwork has not received the attention it deserves. Take a look at  my HVAC Duct article to evaluate and inspect your existing duct work. If you have determined that it is in need of attention you have three choices, 1) do nothing, 2) have them replaced or 3) re-insulate them.

  Duct Replacement: Be prepared, HVAC contractors typically want to sell new systems.  Here is the SW part of the US, their big season is the summer, having this done during the cooler months may be a better choice. Duct replacement is not as profitable as system replacements, but keeping their technicians busy can be better than not working them at all.

Considerations when discussing this issue with a HVAC professional:

  1. Flex ducting is a widely used proven product but does not have the long-term performance rating found with a typical sheet metal product. But is widely used in the residential market and most professionals like to use it because it is easy to install and not as labor intensive as rigid duct work. This product  can easily be mis-installed by creating kinks and  sharp bends that can reduce the product performance. Read this flexible duct inspection method before you meet with the contractor to better understand the product and how it is applied.
  2. After an evaluation, most HVAC specialists will want to replace the ducting in lieu of  repairing or re-insulating. Why? It’s quicker, cheaper and it becomes a known value. This is not a bad thing, these folks are trying to make a living and attacking the problem by replacing everything may be an economical solution for both of you.
  3. If you allow a professional to replace the ducts, make sure to ask some of these questions. Will all the joints and edges be sealed with (paint on) mastic? What is the R value of the new duct? What is the life expectancy of the duct product? What is the product warranty? What preventative measures are followed to avoid kinking (of the ducts). Will the system be tested for leaks after completion?
  4. If the professional didnt mention it,  also consider having all the output and return registers (this is the box in the wall/ceiling where the vent cover is attached) replaced or re-insulated. Most new registers are sealed and insulated to insure a tight fit. Also, ask them to use spray foam insulation between the register protrusion and the sheet rock, this will further seal the interior  from the attic space. Most HVAC professionals do not address register penetration into the interior space.
  5. If you have any rooms that never seem to adequately heat or cool, make sure and mention this to the professional too as he may have to resize or reroute the new duct work to better balance the system.

Duct Re-insulation (for rigid ductwork): This is a great DIY project if you consider yourself cheap labor and you dont mind working in the attic. Consider this a mult-weekend project. Before you start, ask yourself these questions. 

  1. Does your system work reasonably well? If you have any rooms or areas in the house that never properly heat or cool, consider adding an additional output duct as this would be the time to address it. Consider using a professional to perform this work as you may need to rebuild some of the system to retain the system balance.
  2. Is your attic adequately insulated? If not, plan to do it, but after all you other attic work is complete.

 The process if fairly straight forward and here is an outline of the necessary work.

  1. Strip the existing insulation material
  2. Ensure all joints are secure and snapped and screwed together
  3. Use duct mastic to seal ALL seams and joints
  4. Use HVAC tape to complete any seals not treatable with mastic
  5. Use expanding foam insulation to fill any cracks between the duct registers and the sheet rock
  6. Use duct wrap to re-cover all the exposed duct, seal with duct tape and mastic

Material Required for the Job

  1. Duct wrap rated at an R value based on your region (see table below)
  2. 1/4,1/2, and 3/4 self tapping sheet metal screws
  3. HVAC Duct Mastic
  4.  Take adequate precautions while working in the attic. Avoid stepping directly on the sheet rock ceiling and wear protective clothing and dust masks.
  5. If a professional indicates the duct are under/oversized, you may ask them to provide  the Man L or Man J duct analysis supporting their position. (This is an engineering schedule that is used to properly size ducting.)