ODDS & ENDS Our News Letter
In the last column, we spoke about what goes into the thermal envelope of a Zero Energy Home. In this column, we pick up where we left off starting with the next item on the list.
Energy-Efficient Heating & Cooling Equipment
All heating and cooling equipment including ductwork must be located within the conditioned space.
Typical heating and cooling units are too large (and waste a lot of energy) for zero-energy homes. It is crucial that load calculations are performed by the HVAC contractor so that properly sized equipment can be installed.
Domestic Hot Water Energy Efficiency
Two possible efficient options are Tankless AKA On-demand and Air Source Heat Pump Water Heaters. The latter is more efficient.
Things to consider about hot water:
- The distance from the water heater and the plumbing fixtures it serves. The shorter the distance the less energy is lost to the air in transit.
- Stacked plumbing will reduce the distance that heated water must travel between floors.
- Pipe insulation will help retain heat as the water travels through the pipes.
- Air Source Heat Pump Water Heaters give off cool air and may increase the heating load. HVAC contractors should include this factor when calculating heating loads for sizing equipment.
Energy-Efficient Appliances & Lighting
All appliances must come with an Energy Star Rating and all lighting must be LED. When using all Energy Star appliances and equipment you can expect to save up to 30% on your energy bill. True, these appliances may cost more but the increased cost is easily offset by energy savings. Some Energy Star appliances and equipment include:
- Washing machine
- LED lighting
- Charging stations
- And more
Fresh Air Ventilation For A Zero Energy Home
To maintain indoor air quality, whenever the air changes per hour is less than 5 the International Energy Conservation Code (IECC) calls for mechanical ventilation to be installed. Fresh air ventilation for a Zero Energy Home requires the use of an Energy Recovery Ventilation (ERV) unit. These units provide a balanced ventilation system that exhausts stale air while bringing in fresh outside air in equal amounts. Within the unit incoming air is mixed with outgoing air and thus tempered before being circulated throughout the home.
Air Change Per Hour (ACH) For A Zero Energy Home
Air changes per hour, abbreviated as ACH, is the number of times that the total air volume in a space is completely removed and replaced with outside air within the time span of an hour. Air changes occur through leaks and penetrations in the thermal envelope which was the topic of our last column. The lower the number the tighter the home.
The equipment used to measure ACH is called a Blower Door.
The average home in Massachusetts, Rhode Island, and Connecticut will have 5.3 ACH. The requirement for zero energy home is less than 2 ACH.
We expect the move towards Zero Energy Homes to accelerate in this Country. Some states such as Massachusetts are already well underway. Most states will get on board eventually. Builders will need to adjust to this new reality. Many builders have already embraced the concept and are driving it forward. Others have lagged behind and are scrambling to educate themselves and their subcontractors.
HERS Raters and other professionals in the industry will be the go-to for building planning, consulting and verification. They will play a key role in educating builders and homeowners.
Incentives & Rebates For A Zero Energy Home
Fortunately, with programs such as Mass Save, EnergyWise, and the Inflation Reduction Act of 2022, there should be a lot of great rebates and incentives available for years to come to help offset the additional costs of specialized equipment.
Want to Learn More About Minimizing Energy Consumption And Having A Zero Energy Home?
If you’d like more information on how you can minimize energy consumption and maximize savings while making your home more comfortable all year round, then contact Energy Geeks. Our mission is to provide the most comprehensive and efficient solutions to reduce energy use in your home.