ArizonaPriority

Lists

Charlie GohmanAz Dept of Commerce

Energy Office

Arizona Priority Lists(Heating and Cooling Only)

• There are three primary factors in Az priority lists.– Climate (six climate zones)– Construction characteristics (single family &

mobile)– HVAC types (Air Conditioning and Evaporative

Cooling)

• We have 12 priority list, 2 for each climate zone, one for single family and one for mobile.

• In each, measures listed under HVAC types.

Climate

• Six climate ranging from:– 5000 CDD/1300 HDD– 150 CDD/7000 HDD

• In our large population centers, it is hot, dry, sunny 362 days a year and the wind does not blow much. Impact on WAP:– Evaporative Cooling vs Air Conditioning– Solar/shade– Lack of wind/stack shifts our infiltration focus.

Mountains andvalleys makeour climate zones verycomplex.

Solar – shade, shade, shade!!

Wind Resources

I have done long term pressure monitoring,normally under 1 Pa of pressure created by wind and stack.

I am from Minnesota, I know how much of ND blows in each winter

Construction

• Slab on grade

• Vast majority of walls are block or insulated frame/stucco.– Little if any wall insulation added.– Can you blow through concrete? Our homes are

fairly tight (for WAP) and look like a bowl.

• Vast majority of our ducts are in the attic.– 15% return leak at 115º reduces capacity 50%.– Our attics can be over 160º/leakage at 30% & up -

reducing duct leakage critical.

HVAC

• Saving potential in air conditioning Vs evaporative cooled.

• Evaporative Cooling is blind to the envelope.– Evap is a open system moving 4000/5000 CFM,

the insulation, tightness ext. has no impact on energy use.

– Only real savings potential is heating (limited in most of Az), lighting and refrigerator.

We can reduce heating cost through duct sealing!In some cases it makes up for increased cooling in AC conversion

What Does All This Mean?

• Items on priority list are limited.– Insulation– Shade screens (ac only)– New AC

• Most of our emphasis is placed on pressure diagnostics (duct sealing, sealing the ceiling and pressure balancing/mapping).

Climate Zone 2 - Phoenix• Housing Type One: Homes with Refrigeration

Cooling (AC or Heat Pump)– Existing ceiling insulation of R-19 or less

upgraded to R-30.– Pressure diagnostics and repair following the

pressure diagnostic procedure established by the WAP program.

– Air Conditioners twenty years old or older upgraded with a minimum 13 SEER unit.

– Shade screens on all sun struck south, east and west windows and glass doors.

– Water heater wrap (where allowed).

Climate Zone 2 - Phoenix

• Housing Type Three: Homes with Evaporative Cooling Only and Gas Heating– Existing ceiling insulation of R-11 or less

upgraded to R-19.– Pressure diagnostics and repair following the

pressure diagnostic procedure established by the WAP program.

– Upgrade of evaporative cooler motor with higher efficiency two-speed motor.

– Water heater wrap (where allowed).

Mobile Home - CZ-2• Housing Type One: Mobile Homes with

Refrigeration Cooling (AC or Heat Pump)– Reflective roof coating.– Pressure diagnostics and repair following the pressure

diagnostic procedure established by the WAP program.– Air Conditioners twenty years old or older upgraded

with a minimum 13 SEER unit.– Installation of a storm window on jalousie windows

(installed cost of under $8 per square foot).– Shade screens on all sun struck south, east and west

windows and glass doors.– Water heater wrap (where allowed).

Mobile Home - CZ-2

• Housing Type Three: Mobile Homes with Evaporative Cooling Only – Pressure diagnostics and repair following the

pressure diagnostic procedure established by the WAP program.

– Upgrade of evaporative cooler motor with higher efficiency two-speed motor.

– Installation of a storm window on a jalousie windows (installed cost of under $4 per square foot).

– Water heater wrap (where allowed).

Mobile Home

• Reflective roof coating/reduce delta T in place of reducing U-value.

• Jalousie windows – based on study by NACOG on CFM50 reduction of adding storm over Jalousie window. (impacts u-value and air leakage)

Before reflective roofcoating - 93 degree ceiling temperature

After reflective roofcoating – 87 degree ceiling temperature

Economics of Air Sealing

• Infiltration in the low desert is driven by pressures created by fans.– Duct leakage and room pressures

• Our first priority is reducing house pressures through duct sealing and pressure balancing.

Small driving force, minimal air flow!Long term monitoring of natural pressures

always under 1 Pa. Divide by 20 assumes 2.5 Pa

Our Pressure Balancing Goal

• As close to zero pressure as possible (duct leakage and room pressure).

We take duct sealing very seriously

Duct Crawling 101Classes start soon

Economics of Air Sealing

• Review of air sealing finds:– Duct sealing/pressure balancing –very cost

effective.

– Shell air sealing– There is a good percentage that has not been cost effective. In response, developed the following guidance to increase the effectiveness of shell air sealing.

Economics of Air Sealing

• Using computer models and field studies to estimate the value of air sealing.

• These values can provide guidance on how much can be cost effectively invested in air sealing.

Infiltration

Present value of 100 CFM50 reduction in infiltration. (Based on LBL numbers)

Climate zone 1= $160Climate zone 2 = $40Climate zone 3 = $90Climate zone 4 = $40Climate zone 5 = $90Climate zone 6 = $40

Air Sealing Budget

• Establishes a “not to exceed” amount for shell air sealing work.

• Basically the value of the CFM50 shell air sealing potential of a job.

• Goal is to reduce the number of jobs where too much money is spent on ineffective air sealing.

Air Sealing Budget

• The difference between the post duct sealing CFM50 and the final CFM50 goal (300 CFM/1500 CFM50) is the potential CFM50 infiltration reduction.

• Use the economics of air sealing, establish the potential value of air sealing if you reach the goal. This is the air sealing budget.

Example

• 2500 (post duct sealing) CFM50

• 1500 CFM50 goal

• 1000 CFM 50 potential

Air Sealing BudgetUsing the 1000 CFM50 example

• 1000 CFM50 potential:– CZ 1 budget of $1600 (10 x 160)– CZ 2 budget of $ $400 (10 x 40)– CZ 3 budget of $ $900 (10 x 90)– CZ 4 budget of $ $400 (10 x 40)– CZ 5 budget of $ $900 (10 x 90)– CZ 6 budget of $ $400 (10 x 40)

Budget in Phoenix - $400

Next – Feedback

• Next step involves using the blower door to give you feedback on your air sealing efforts (CFM50 reductions)

• Tracking the cost of achieving these reductions.

• Comparing this information with the present value information provided in the economics of air sealing can give you an idea of the cost effectiveness of your work.

Questions