Conference Call Friday June 19 8:30-9:50 a.m.
Amy, Kevin, Jeff, Michael, Gerome, Brent & Emmanuelle
Update on Home Energy Rating System (HERS) analysis from Brent:
Analysis with existing building provided a HERS index of 89, which could get down to 77 by changing the boiler to a more efficient one.
With the addition of a 19kw, double access pv- array, and a more efficient boiler the HERS score drops to 33.
Then, with the addition of 3, 4X10 solar thermal-collectors, HERS score drops to 24. Also, the original simulation used the load of a regular refrigerator, when updated with a current model, the score dropped by 1, bringing the score down to 23.
If 50% of the incandescent cans are converted to CFL (compact fluorescent), the score will drop to 20. This score could surely be lowered by switching to LED lights, but the current 2004HERS projection model doesn’t provide for this alternative (a CFL is about 50% less efficient than LED).
With the geothermal system, the HERS goes down to 4 -almost netzero: producing almost as much energy needed-, 96%more efficient than a 2004 regular home.
Based on the most current floor plan including the addition and green house, and based on current and past usage, the system requires 40,000kw/year. The array needs to be 19,000kw, with 7 or 8 towers (3kw/tower) to complete the electrical need. The goal is to get down to 15-16kw.
We need to look at the five categories below to reduce the load:
Geothermal-heating hot water (40.5%of the total energy load: exactly 41, 0006kwhours), appliances (9.5%), lighting (33% of the total load), hot tube (11%), and green house (6%).
LED Lights:
LED light can save up to 80% of energy required for lighting: www.lightolier.com
Direct incandescent LED replacement: www.ledtronics.com
(might be as efficient but not as bright as LED fixture)
The energy required for lighting could considerably be reduced by changing 50% of the existing lighting to LED and use motion sensors. It would take work to uncover cans, but access is good. Need to remove and replace the casing.
Skylight/tube:
Another way to cut artificial lighting in kitchen would be to install a skylight or light tube. Light tubes might be a better choice because of the attic above. Amy likes the idea of the light tube but is concerned that light tubes provide less light than skylights. Two tubes could possibly be installed within the existing trusses.
However, it might be less expensive would to retrofit the cans and install LED than using a skylight. Also, skylights let energy out more than tubes do. In the winter, snow would accumulate on skylights, whereas snow would probably melt quickly on a tube that would be placed higher on the roof surface, would be composed of a black cylinder and concave top.
Polycarbonate Panels
If we change polycarbonate panels to a thicker honey-comb 25-35mm to 45 mm, the U Value would increase from .3 to 19 (equivalent to R3 to R5 value). Michael thinks that the light transmission value would be affected but can be sacrificed for a net zero value. Brent believes that the thickness of the panels will not affect heat that match since the climate battery will heat the green house 90-95% of the time.
Geothermal:
8 vertical holes or possibly 7 would be the best scenario. Kevin would like to know what it would take to get to 6?
10-20% can be shaved for lighting and appliances.
The hot tub does not affect the geothermal number, electrical only.
Is it realistic to think that we can shave 20-30% of the heating load by replacing the front door, and doing other retrofits?
The geothermal load (btu load) is for Hot water and heating, in the even that the solar collectors don’t produce enough hot water, but the best investment remains the solar thermal collectors.
The Rinnai on demand gas water heater is a good system but would be redundant since the boiler will be there.
The only way to reduce the geo load is to get the envelope tighter, and to get a better value out of the soil. The average TC (thermal conductivity) is 1 value, however, a man in the Rifle area claims he can get 1.25. For the analysis, Brent used a conservative PC value of .75 but believe that because of the humid soils and the area the PC value is probably higher.
Kevin would like to know if we should go horizontal or vertical. 8-10 vertical wells would occupy half of the area of horizontal wells. Horizontal geothermal is cheaper and nets the same output as vertical. Ti would require 9 strips 100feet long and 3 feet wide, and would approximately expand to a pit 40 feet wide by 100 feet. Brent will make a price comparison between 2 to 3 weeks.
Appliances:
The dishwasher and refrigerator are efficient and do not need to be replaced. The garage refrigerator could be replaced, and the small refrigerator by the pool and wine cooler could be turned off. The washer and dryer could be replaced by more efficient ones (Asko).
The TV plasma screens and projectors require high energy but are not used very often, mostly the TVs in the kitchen and bedrooms are used a few time a week.
The TV, computers, etc. can be plugged into a power strip that will shut off all equipment and not use any idle wattage.
Heat pump/single phase/triple phase power:
Is there a heat pump that is more energy efficient than others? Limited but only a couple of companies that make a single phase power.
3-phase power could be used to run new electrical. Is there 3-phase power at the transformer near the house?
Solar:
The PV dual tracking array is 19kw. A 30% additional cost for tracking makes sense to get 30-40% return on investment. All the PV should be on trackers. The solar thermal will go on the roof –only 4 panels-.
Climate Batteries:
Michael could drop the water tank at the bottom of climate battery and create a water depth of 5 feet, high enough to swim with the carp…
Action Items:
1. Everyone: List of sacrifices that could be made on:
Lighting, appliances, geothermal, hot tub and green house.
Share any technology you might be aware of to reduce energy load and create a better envelope.
2. Gerome, Lisa and Michael: Green house design with detailed planting design.
3. Michael: Mechanical drawings for Jeff to start converting conceptual drawings into construction drawings.
4. Brent: Contact person in Rifle regarding TC. Schedule TC test and model horizontal/vertical geothermal.
Contact YVEA, Jim Chappell, to locate nearest 3-phase power.
Size boiler.
5. Amy and Kevin: Visit light store to view LED lighting-luminosity and color-.
No comments:
Post a Comment