Cold-Climate Research Round-Up

The Midwest is home to the leading clean energy field research organizations in the country. They specialize in testing new technologies and program approaches in the field to evaluate actual energy savings potential for utilities, building professionals, communities, and states.

In this webinar leading experts from CEE and Seventhwave lead a rapid-fire discussion of innovative tech and program approaches, and the most meaningful recent research findings for utility representatives, efficiency program implementers, and both residential and commercial field experts.

Covered topics
  • Commissioning for daylighting controls 
  • Optimizing operation of buildings with indoor pools
  • Energy Recovery Ventilation (EVR) effectiveness
  • Maximizing energy savings from Demand Control Ventilation(DCV) systems
  • Cold-Climate Variable Refrigerant Flow (VRF) system optimization
  • Innovative aerosol sealing in multi-family buildings & single-family homes
  • Next generation Air Source Heat Pumps (ASHPs) in cold climates
  • Hybrid geothermal achieves highest performance

View the slides and watch the recorded webinar below.

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Q&A Responses 

Daylighting Controls: Any comments on the incremental costs of installing daylighting controls versus just vacancy control? Is it worth the additional cost to install daylight control?
That’s a complicated question and the answer depends on a variety of factors (space type, daylight availability, controlled lighting power…). In general, both controls are cost effective (hence their continued inclusion in new construction building energy codes). Care should be taken however to remember that the savings from each individual technology is more than the savings from both technologies combined (i.e. for a given hour of the day a space may be both unoccupied and have significant daylight present).

Daylighting Controls: Did the findings take in to account lighting control impacts from different seasons (wi th different daylight hours)?
Yes. Although our monitoring periods were only for a portion of the year, we extrapolated to annual savings by normalizing via daytime hours and total daylight availability.

Daylighting Controls: In your slide diagrams, where is the dimmer box located? On the roof or the ceiling? Is it near a window?
Are there several units per floor. For a given system, the dimming control (not the photosensor) can be located in a variety of places. Often, it is in the fixture itself, but could be located in a central location in the case of head end equipment.

Variable Refridgerant Flow: If the VRF is in a mechanical room at -10F, I assume it's important for the room to be well insulated. Was that looked at?
We included conduction through the mechanical room walls and roof in our modeling. However, it appeared that this heat flow was minor compared to the other heat flows. Therefore, having some level of insulation (i.e. R-5) is a good idea, but there is no need to heavily insulate the mechanical room.

Variable Refrigerant Flow: Are VRFs still effective in cold/extreme temperatures?
Air source VRF capacity and efficiency drop off at extremely cold ambient temperatures. The intent of this research was to explore ways to mitigate this effect, such as a semi-heated mechanical room. This approach certainly makes air source VRF an option even under cold conditions. Other options include ground source or water source systems. Also, manufacturers are developing (and recently bringing to market) air source systems with better performance under extremely cold conditions.

Envelope Sealing: What is the aerosol sealant made of?
It is a synthetic acrylic that is sprayed or rolled on surfaces to produce a monolithic air barrier membrane. It is an off-the-shelf product that is typically used on exterior, above grade applications. It is diluted for the aerosol application. It is low-VOC and has GreenGuard certification.

Geothermal: Do the hybrid geothermal systems use tradition loops?
Yes, they use traditional loops. Adding a conventional system reduces the size of the ground heat exchanger needed.