# Presentation: 127420

## Building Energy Efficient Homes:New Construction and Rehab

- HERS 86 (EnergyStar) minimum
- 30% Better Than the M.E.C.
- Other Considerations:
- Affordable; Durable; Healthy

- William Zoeller, R.A.

## Major Systems Affecting Building Energy Performance

**Building Envelope**
**Air-tightness, Insulation levels**
**Water-management**
**Windows and Glazing Systems**
**Glazing SHGC**
**Overall “U” Value**
**Heating, Ventilation, and Air Conditioning**
**Equipment sizing, efficiency and location**
**Duct tightness, distribution effectiveness, and location **

## Major Systems Affecting Building Energy Performance

**Domestic Hot Water**
**Generation**
**Distribution**
**Stand-by-losses**
**Appliances**
**Refrigerator, dishwasher, clothes washer/dryer**** **
**Lighting and miscellaneous**

## Panelized Advanced Framing

- Panelized Advanced Framing 2 x 6 Walls @24” OC
- Low-e Windows
- Foamed Stud Cavities with Blown in Cellulose (R-23)
- Inside-The Envelope AHU
- Foamed and Insulation Buried Ducts
- Affordable and Starter Homes
- HERS 89

- Outlook ConstructionAtlanta, GA

## Panelized Advanced Framing
Reduces Framing Cost and increases Level of insulation
Reduces on-Site Labor and Construction Time
Requires Additional Planning, But Improves Systems Integration

- Reduces Framing Cost and increases Level of insulation
- Reduces on-Site Labor and Construction Time
- Requires Additional Planning, But Improves Systems Integration

## Insulation-Buried Ducts

- Computer Modeling of Heat Flow
- From Insulation Buried Duct

- Section Through Foamed Over Insulation Buried Duct

| All ducts fully buried with several inches of insulation | Larger trunks barely buried and smaller branches fully buried | Larger trunks partially buried |
| --- | --- | --- |
| R-30 | R-15 | R-10 |

## Buried Duct Benefits
Improves air distribution efficiency 
Provides additional air-sealing at joints and registers
Reduces Peak load allowing a smaller system to be used
Cost of foam can be offset by reduced cost of HVAC

- Buried Duct Benefits
- Improves air distribution efficiency
- Provides additional air-sealing at joints and registers
- Reduces Peak load allowing a smaller system to be used
- Cost of foam can be offset by reduced cost of HVAC

## PANELIZED WALL AND ROOF SYSTEMS

- 25 Home In-fill Development
- Panelized SIP Construction
- R-24 Walls
- R-40 Roofs
- 92 AFUE Furnaces
- Mastic Sealed Ducts
- 1.2-kW PV Solar Systems
- Low-e Windows
- EnergyStar Appliances
- Compact Fluorescent Lighting
- Controlled Ventilation

- Claretian AssociatesSouth Chicago, Il

## First SIP Project in Chicago

- $155,000 cost for 1700 SF Home
- 5% Increase in Cost of Standard Construction
- 50% Increase in Energy Efficiency

## Panelized Wall and Roof Systems

- Cement Board Structural-Insulated-Panels
- Aluminum-Skinned SIP Roof Construction
- Structural-Steel Moment-Frame at Centerline
- Sold as Pre-Engineered Kit to Builder
- Standard and Custom Designs Available
- Low-Cost and Durable

- Homefront Homes

## Cement Board SIP Panels

- Hardie® 5/16” thick cement board laminated to both sides
- 	of 4” thick polystyrene foam
- Cuts construction time by up to 75%
- High minimum R values with R-20 walls and R-30 roof
- No wood used in the home construction to avoid moisture
- 	and termite damage

**Panelized Wall Construction System:**

**3 days to complete the building shell**
**	****	****	**

## Home Front

- 	Home Front homes proved exceptionally resilient when Hurricane Charley struck in August, 2004

- Before Hurricane

- One mile away....

- After Hurricane

## Unvented Crawlspace

- Improved Energy Efficiency
- Improved Indoor-Air-Quality

## Low-e Glass Windows

**Low-e glass blocks out most long-wave radiation (heat) while allowing most of the short-wave radiation (light) to enter.**

## Typical Costs

**Extra cost for 300 SF low-e coating on double glazing: $300.**
**Savings in downsizing AC by 1⁄2 ton: $275.**
**Net cost: $25.**

## Additional Benefits of Low-e Windows

- Reduced cooling load needs smaller HVAC system
- Smaller HVAC system means lower air-flows, and simpler pressure balancing
- By being more closely matched to both peak and non-peak cooling loads better dehumidification is achieved
- (Improves IAQ and inhibits mold growth)

## HVAC Optimization

- HVAC Optimization

**“****Right-Sized” HVAC **
- Manual J with no oversize
**Compact design**
- avoids ducts in outside walls
- Less opportunity for leaks and losses
- Less costly to install
- Better able to achieve air-flows

## Concrete and Panelized Construction
Low-e windows
Integrated HVAC
AHU in Conditioned-space
EnergyStar Qualified

- OPTIMIZED HVAC
- Mercedes Homes Townhouses
- Melbourne, Florida

- Concrete and Panelized Construction
- Low-e windows
- Integrated HVAC
- AHU in Conditioned-space
- EnergyStar Qualified

## Down-Sized HVAC

- Single Zone 1.5 Ton Capacity Heatpumps
- Compact Distribution
- First and Second Floor Returns
- Fresh-Air Duct

## OPTIMIZED HVAC COMFORT TESTING

## Tankless Gas Water-Heater

- ECO-Block Walls
- Fly-Ash Concrete
- Low-e Windows
- Integrated Compact HVAC
- SEER 17 A/C
- Tankless Water-Heater and Hydro-coil AHU
- HERS 95

- Madera I Model Home, Gainesville, Florida

**Takagi T-KD20**

## Cost and Benefits

- Saves Space: Much smaller than a storage tank
- Saves Energy: Stand-by losses are eliminated. Operating efficiency improves by 30% to 40%
- Saves Energy: For space heating, .84 AFUE is higher than standard furnace at .80 AFUE
- Incremental cost increase is about $600. Very short initial pay-back, and immediate positive cash flow.

## Heat Pump Water Heater

- Installed in a home in Melbourne, Florida
- WatterSaver Integrated HPWH by ECR International, Inc. (product introduced Fall 2002)
- Monitoring began in April 2002
- 3-person household (2 adults & toddler)

## Preliminary Findings

- Reliable Performance
- Homeowners very pleased
- 62% kWh savings
- $10/month savings at local electric rates of $.077/kWh

## Energy-Efficient Lighting, Appliances, and Controls

**Takoma Village, Washington, DC**

## Takoma VillageWashington, D.C.

- Other Sustainable Features
- Energy Efficient Lighting
- Low-VOC Paints and Finishes
- Fiber-Cement Siding
- Recycled-Content Carpets
- Horizontal-Axis Clothes Washer
- Tubular Skylights

## Putting It All Together

- Warwick Grove,
- Warwick, NY

## Putting It All Together

- Advanced Framing
- Unvented Crawlspace
- Low-E Windows
- Optimized HVAC
- 92% Condensing Furnace
- 13 SEER Air-Conditioning
- Tankless Gas Water-Heater
- EnergyStar Appliances
- HERS 89 -90!