Executive Summary

 

After inspecting this home we find that there are causes for the high heating bills and potential to reduce these bills. The major recommendations for this home would be installation of a vapor barrier in the crawl spaces to reduce moisture infiltration, air sealing in the attic and basement and improvement of the current insulation. These actions should reduce heating and cooling costs, provide more consistent temperatures throughout the home and reduce the appearance of drafts.

Based on our findings we estimate that you have a potential to save $200 per year based strictly on insulation and air sealing, at a cost of $1550 yielding an approximate payback period of 8 years. This work yields other intangible results such as improving pressure balances within the home that will also affect savings.

Your air quality is good though the current air leakage may contribute to poor air entering the home through the building materials.
The Combustion appliances appear to be in good working order and are venting properly to remove hazardous fumes from escaping the home.

 

Home information

Client Joe Homeowner

Address 123 Main St

DuPage, IL

Phone 555-867-5309

Test Date 1/1/11

# of occupants 3

# of Bedrooms 3

#baths 3

# of stories 1

Foundation type Basement

Foundation part of conditioned space Yes

Home measurements

Length Width Height Area Volume
Section 1	81	32	9	2,592	23,328
Section 2	37	20	9	740	6,660
Section 3	-23	-30	9	-690	-6,210
Section 4
Section 5
Section 6
Overall Totals				2,642	23,778

 

Homeowner concerns

 

Homeowner stated that after moving from a smaller home to this home they had a dramatic increase in their heating bills. Some of this was attributed to the size of the home but they are concerned that there are other more significant issue.

There is a concern that there is a gas leak from an old gas line

·         Upon visual inspection there does not appear to be a gas line in the area of concern

·         There is sign of gas leaks when inspected with gas detection equipment

 

Homeowner discussed the possibility of getting new windows due to drafts and broken seals

·         Under a depressurized state the windows do not show any signs of leakage.

·         Though there may be broken seals, the added benefit of new windows vs. the cost of replacement does not warrant window replacement (see window schedule)

 

Homeowner stated that the office area gets very warm in the winter

·         This situation is most likely due to a variety of factors.

o   The office area is of newer construction and is likely have better wall insulation

o   Under depressurized conditions it was observed that there is minimal air leakage which can be attributed to the office area meaning that it is most likely retaining heat better than other sections of the home

o   The whole house fan which is the cause of a great deal of air leakage and therefore also heat loss is located in close proximity to the thermostat and is therefore calling for heat more often than may be necessary

o   The office area is the closest room to the Furnace position and perhaps the duct sizing does not adequately account for this factor.

 

The homeowner stated that there are condensation issues in the home

·         The most apparent cause for this condensation would be the fact that the crawl spaces do not contain a moisture barrier and this with their proximity to the furnace is most likely causing excess moisture to be transmitted throughout the home.

 

The windows in the child’s bedroom and the guest bedroom appear to be exuded a brown liquid

·         Nothing is apparent to suggest a cause for this but it is possible that the excess moisture in the home in combination with a sub layer of stain on the windows that may not have been adequately sealed prior to painting are causing this situation

Property Conditions

 

Windows

Total # 8

Glass Type Double pane

 

*see window schedule for detail (if applicable)

 

Comments: The windows appear to be in reasonable condition though it is possible that a couple of them have lost their seals. Based on the thermal resistance of the current windows and the savings calculations performed in the window schedule section it would not be recommended to replace the windows at this time. The savings to be derived from this action would require a minimum payback period of 60-90 years.

 

It was observed that there were no window treatments on a number of windows and by adding, especially on the south and west sides of the home there might be some nominal improvement in the homes ability to maintain a cool state during the cooling season.

 

Observations

During visual inspection of the home and upon depressurization the following items were observed

Leaky glass blocks in the back basement

Cobwebs and dirty insulation in rim joist pockets

Fireplace Flue was in an open position and had apparently been so throughout the winter.

·         This was most likely a contributing factor in the homes high heating bills

Leakage from kitchen exhaust hood

There is a Whole house fan which contributes significantly to the air/heat leakage

Some window panels may have leaky seals

Crawl space does not have any moisture barrier

The insulation on the sidewalls of the vaulted ceiling is only R-13 and based on the position should likely be covered with more insulation or preferably ridged foam board.

The insulation over the vaulted entryway was installed very poorly and should be reset to eliminate air pockets between framing members

Air sealing is needed throughout the attic where electrical and plumbing penetrations exist.

 

Measurements *For details regarding these calculations refer to the calculations section

 

Home Heating Index 22

 

*This number is a comparative guideline regarding your home and it’s energy efficiency based on your energy consumption and the area of the home. The scale ranges from 2 to 20+ with a 2 being highly efficient. This number alone should not be used to base decisions on.

 

Blower door results 3700@CFM₅₀ (4700@CFM₅₀ was originally measured but it was found that the fireplace flue was open at the time)

200@CFM_N

 

*This is a measurement of the homes air leakage or the amount of air escaping the home. CFM₅₀ stands for cubic feet per minute at -50 pascals of pressure which is the level at which the home is depressurized to run this test. CFM_N Stands for the cubic feet per minute expected to be lost under natural conditions. These measurements take into account external pressures such as the wind strength at the time of the test.

 

Estimated leakage area 370 Sq. In. = 2.57 Sq. Ft.

*This is an estimate of the total area of leakage to the outdoors as if you had a window that you left open at all times.

 

Air changes per hour 9.37 @CFM₅₀

.50 @CFM_N

*A home needs to refresh its air supply through proper ventilation. Acceptable levels for this number are above .35/person under natural conditions.

 

 

Minimum Ventilation 2,566@CFM₅₀

138@CFM_N

*This number can be compared to the blower door results to determine the amount of air sealing that can be performed before mechanical ventilation would be required

 

Insulation

Type Fiberglass batts

 

	Attic dimensions	Thickness	Approximate R value
Attic 1	58’ x 32’	6”	R-19
Attic 2	37’ x 20’	6”	R-19

*Current code for new homes in DuPage County is R-38

Based on the stated R value of the insulation and the installation and deficiencies that were observed we will assume an approximate productive value of R-16 for calculations

 

Combustion Safety Test Results

 

Water Heater - GAS

 

Comments

The water heater appears to be 30 or 40 gallon but no nameplate was found to identify. The water heater shows no sign of flame rollout or other signs of failure. It is advised that the water heater be drained and cleaned at least once a year. Upon forcing the burner to test spillage, the unit shows proper draft within the prescribed 1 minute time frame.

 

Furnace – GAS forced air

 

Comments

The furnace appears to be in good shape with no signs of flame rollout. The nameplate was not visible so the unit capacity was not apparent. At the time of inspection the panel was off of the unit and it is advised that this panel be restored to its proper position

 

 

Worst case Depressurization

 

During worst case depressurization of the home the pressure was measured as follows:

All exhaust fans running w/hot water heater on -2.3 Pa

All Exhaust fans running w/Hot water and furnace -3.2 Pa

All Exhaust fans running w/Hot water and furnace CAZ door closed -3.5 Pa

 

All of these readings are within the acceptable range

Nothing in the Combustion Appliance Zone shows cause for concern

 

Recommendations

 

Based on observations and homeowner comments the following work is suggested

Basement

·         Install and seal plastic sheeting in the crawl spaces (highly recommended)

·         Seal Rim joists in basement (highly recommended)

·         Caulk around glass block windows

·         Install water heater blanket to reduce heat loss and improve efficiency of unit

 

Main Floor

·         Install outlet covers on exterior walls

·         Install Low flow aerators

Attic

·         Seal top plates and all conduit penetrations (highly recommended)

·         Install ridged insulation on side walls of vaulted ceiling

·         Build and seal cover for whole house fan (Highly recommended)

·         Remove current insulation from vaulted ceiling over entry and reinstall. Blow cellulose on top to cover (highly recommended)

·         Blow in ~6” of cellulose insulation throughout the attic to improve insulation factor as well as fill in gaps in current insulation

 

Air Leakage Savings

Based on the estimated air leakage improvement there will be a calculated savings due to air sealing of approximately $54-$86/year. Given this and the estimated cost of air sealing activities there would be a 5-8 year payback for this work based solely on the calculated savings

 

Attic Insulation savings

Based on the current level of insulation and the recommended improvement it is estimated that there will be a calculated savings due to insulation of approximately $104/year. Given this and the estimated cost of blowing in insulation there would be an 8 year payback for this work based solely on the calculated savings

 

 

Calculations

Home Heating Index

HHI = Q*364(days/year)*100,000(conversion to BTU’s) / (A x HDD)

HHI=10.56*364*100,000/(2642 x 6500)=22

Where

Q = Average daily therms of fuel consumed during the year

A = Heated Floor Area

HDD = Heating Degree Days = Total # of average daily degrees below 65 in a given year. If on a given day the average temperature is 35 degrees you would accumulate 30 heating degree days

 

CFM_N = CFM₅₀ / 18.5 = 3700/18.5 = 200

 

Estimated Leakage area – this can only be considered an approximation and is reported in Sq. In.

 

CFM₅₀/10

370 Sq. In = 2.6 Sq. Ft.

 

Air Changes per hour

 

ACH₅₀ = CFM₅₀ x 60 / V (Total volume of the conditioned space)

ACH₅₀ = 3700 x 60 / 23778 = 9.37

 

ACH_N = ACH₅₀/N (Correlation Factor based on the house type)

ACH_N = 9.37/18.5 = .50

The standard minimum Air changes per hour should be at least .35 which leaves room for air sealing without concerns about a decline in indoor air quality

 

 

Minimum Ventilation Guideline (MVG) – measured in CFM_N or CFM₅₀

 

MVG_N Is the higher of:

.35 x V (volume)/60 or 15 CFM x # of occupants

MVG_N = .35 x 23,778 / 60 =138 or 45

 

MVG₅₀ = MVG_N X N (Correlation Factor based on the house type)

MVG₅₀ = 138 x 18.5 = 2,566 CFM

 

Air Leakage Savings

 

Savings = 26 x HDD x Fuel Price x CFM₅₀(change) x.6

N x Heating Efficiency

 

Savings = 26 x 6500 x .7 x (3700-2500) x .6 = $54

18.5 x .85 x 100,000

 

If we could get down to the minimum ventilation level possible prior to requiring mechanical ventilation we could achieve a savings level of

 

Savings = 26 x 6500 x .7 x (3700-1800) x .6 = $86

18.5 x .85 x 100,000

 

 

Where:

HDD = Heating Degree Days which is the total degrees per day for the year that the temperature in Chicago is below 70 degrees

Fuel price is in $/Therms (the equation actually gets divided again by 100,000 to convert to BTU’s)

CFM₅₀ (change) is the reduction from the current state to the minimum ventilation level

N is a calculation factor based on the home style and characteristics

Heating efficiency is the furnace efficiency

 

 

Insulation Savings

 

(1/R_existing- 1/R_new ) x A (area of attic) x HDD (heating degree days (6500)) x 24 hrs x $/Therm ($.6159)

100,000 BTU’s/Therm

 

(1/16 – 1/38) x 2642 x 6500 x 24 x .70 = $104/year

100,000 BTU’s/Therm

 

Based on an installation cost for this material of $700-900 there would be a payback period of 7-9 years. There is also a value in the comfort factor that would be achieved through equalized heating throughout the home.

 

 

Window Schedule

 

Window	Direction	Type	Material	# of Panes	Size
Living Room	West	Casement	Wood	2	10.5’ x 4.5’
Front door	West	Door w/ side panels	Wood	1	4.5’ x 80”
Bedroom 2	West	Casement	Wood	2	6.5’ x 4.5’
Bedroom 3	West	Casement	Wood	2	6.5’ x 4.5’
Bedroom 1	East	Casement	Wood	2	7.5’ x 6’
DR Sliding Door	East	Slider		2	6.5’ x 80”
Kitchen	East	Casement	Wood	2	24” x 48”
Kitchen	East	Casement	Wood	2	24” x 48”
FR Sliding Door	South	Slider	Wood	2	12’ x 80”
Family Room	East	Casement	Wood	2	11’ x 5.5’
Office	East	Casement	Wood	2	6.5’ x 4.5’

 

The total surface area of windows in this home is approximately 407 sq.ft.

Based on this factor the heating savings that could be achieved from replacing the current standard double pane windows with double or triple pane low e-glass windows is as follows

 

 

Window type                                                 Current/future heating cost for window area                         Savings

Double Pane Low e                                                     $116                                                                                              $108

Triple Pane Low e                                                         $ 54                                                                                              $170

 

Based on these estimates, the payback period for new windows per $1000 in cost would be as follows

Window Type                                 payback in years /$1000 cost

Double Pane Low e                                     9.25 years

Triple Pane Low e                                        5.88 years

 

Assuming a rock bottom minimum of $10,000 to replace all windows in the home there would be a 60-90 year payback period