2021 Webinar Series - 3 Virtual Top Job Finalists 3&4
The GeoStar Top Job Competition highlights and recognizes the incredible talent, creativity and imagination that exists in geothermal system designers and installers.
After the final session on April 27, you'll get a chance to vote and help pick the winner! The winning entry will receive a $500 Cash Prize.
Finalists 3 Congregation Beth-Israel by Achieve Renewable Energy, LLC
- Can Larry explain the renewable energy credits? Is it true that no federal tax credits could be used on this project?
- Answered live - Yes, there was no Federal tax credit because the Temple is non-profit. The renewable energy credits are earned based upon the renewable thermal energy harvested. The credits are sold via a market-based system.
- Can Larry give some specifics or good estimates on operating cost or greenhouse gas reductions
- Answered live - I have spoken to our Client and have a more nuanced response than I had live. Prior to COVID, energy cost for the building was reduced by 20+ percent. Given the elimination of fossil fuel gas use, HVAC-related GHG emissions at the building have been reduced 100%. Taking into account the GHG intensity of the current electric grid, GSG emissions are reduced by about 40%. There is an option for 100% renewable electricity which would, again, reduce GHG emissions to zero. During COVID, building operations have been different. Please see the answer to Question 8, below, which addresses the impacts of COVID.
- What percentage of energy usage and operational cost reductions were achieved through the geothermal system - energy cost savings - not including the maintenance costs of the new system etc
- Answered live - Also, please see written responses to Questions 3 and 8.
- ...follow up on savings questions. Is there an anticipated payback schedule?
- Answered live
- What is the waterfurnace Symphony system?
- Answered live - Symphony is a remote access and data logging system. Each GSHP has a device that connects it to the Internet. Data from each device uploads to servers maintained by WaterFurnace. Symphony is the interface used to access the data.
- What did people from the synagogue say about their experience before, during, and after the installation?
- Answered live
- Do you know how many $/ton and how many tons total were installed?
- Answered live - I can give a more complete response in writing. First, it is important to establish what is meant by $/ton. The dollar part is simply the project cost. The ‘/ton’ portion is less clear. Some people divide by the nominal capacity of the equipment (which I approximated in the live response); others divide by the AHRI rated capacity; and some (us usually) divide by the peak heating load. So, we can get three different results. There are 75 nominal tons which would give a cost per ton between $9,000/t and $10,000/t. We think it is better to calculate based on peak heating load which is about 58 tons. This yields a cost per ton between $12,000/t and $13,000/t. You can see the result depends on interpretation of the question. These calculations are based on pre-incentive cost. See Question 18 for post-incentive cost.
- Does the customer make any use of setbacks to reduce temperature when rooms are not in use?
- Answered live - Client input allows this written response to be more nuanced than the live response. Pre-COVID the Client made use of setbacks in different portions of the building and saw benefit. This was most notable in the both the Sanctuary and Social Hall. These rooms are large and have up to 30-foot ceilings. Services are held at the Synagogue each day. Pre-COVID, one daily service was held in the Sanctuary with a subsequent meal in the Social Hall. The other six days, services were held in the library which is 400 SF with 9-foot ceilings. During COVID, operations changed and all services were held in the Sanctuary and Social Hall (approximately 4,000 SF). A movable wall was opened to make one large room that had both a large air volume and available space for social distancing. The Client is thrilled that this significant change only resulted in a 20-30% increase in operating cost compared to the previous fossil fuel system. By their estimation the increase in cost with the old heating system would have been much, much higher.
- Great Project! Were there issues with drilling in a residential community and how were they operating the conditioning equipment prior to your system programming?
- Answered live
- were any building envelope improvements made in addition to the GSHP system?
- Unfortunately, there were not. We encourage building-envelope upgrades concurrent with our projects. Most of the walls are exposed concrete and do not offer an option for insulation. We evaluated spray foam insulation of the roof and the cost was prohibitive.
- What is the building system circulation max temperature
- I am not sure I understand this question. If you are asking about the maximum loop temperature during the cooling season, in 2020 the building loop temperature did not exceed 70 F.
- but how about the experience during the installation? how long did it take? how much did they have to adjust their activities? did they move temporarily?
- The project was conducted during the heating season. This was not our choice but fit the Congregation's schedule. Temporary heat was used for part of the Winter. The project duration was about 6 months.
- Where did you get that pump station?
- The circulation system was purchased from Phoenix Energy Supply. I hesitated to answer given that we bought it from one of the other Finalists and I don’t want to give John Manning a big head. Joking aside, the circulation systems available from Phoenix are well designed and flexible. We have used them on several projects and will use them again in the future.
- Can you explain what Symphony does for those who don't know? Would ONSITE greenhouse gas emissions be zero now with no fossil fuels in use?
- Please see the answer to Question 5 relative to Symphony. Yes, on-site GHG emissions related to HVAC are now zero. With use of renewable electricity, the GHG emissions could be zero overall.
- is that cost per ton net of incentives?
- Please see response to Question 18.
- Our HeatSmart CNY campaign is working with houses of worship to install heat pumps and one of the issues is the uneven occupancy and use schedules of these buildings. How does this affect the efficiency or cost-effectiveness of these systems? Can we express this as a percentage penalty from typical installation with constant settings?
- At a small scale, uneven occupancy is not ideal for GSHP installation. At the commercial-scale of a house of worship (or other scenarios like offices), setbacks can be beneficial. I don’t believe that there is a penalty here. With sufficiently long setbacks in various portions of the building, the efficiency benefits are not lost. GSHPs are just as efficient at the setback temperature as the occupied temperature. The issues are whether the setbacks are sufficiently long and whether the controls used to recover from the setback have smart algorithms. If one can avoid high-stage compressor use and auxiliary heat during the recovery period, then there can be benefits with little or no penalty.
- 70 tons for 7000 linear feet of borehole translates to 100 lf per ton. How much of that is due to high transmissivity of energy in the rock and how much is due to varied occupancy.
- This is based on the live answer to Question 7. Please see a longer answer there related to $/ton. For loop sizing, it is important to consider peak heating load not nominal tonnage. Based on peak heating load, there is 120 feet/ton. In the bedrock at the site and given the close balance of heating and cooling loads, this amount of drilling is adequate. I am not able to parse the proportion of the design related to the two factors.
- does the $8-9k per ton take in consideration the $196k incentive or is that before incentive?
- Please review the written response to Question 7 for discussion of pre-incentive cost. Post-incentive, the cost per ton was in the lower range in this question.
Finalist 4 - Historic Orchard House by EnergySmart Alternatives, LLC
- Couldn't foam insulation be blown into the spaces between the walls from the outside, and holes patched to conform to the original?
- Answered live. It was made very clear to us that insulating the building was not an option. This is really a question for the Orchard House architect/consultants.
- What can Melanie tell us about her company? What dill they do with the drilling waste?
- Answered live- We did not encounter a lot of water while drilling so there wasn’t a lot to clean up. Drilling waste was managed on-site. Drill cuttings were buried in the excavation. No materials were taken off-site.We are a design/build geothermal heating and cooling company. We do quite a bit of work in-house but sub out drilling, excavation, and sheet metal. We tend to stay under 30 to 40 tons capacity.
- Terrific project! Could you walk us through the energy usage chart? Do you have an annual savings estimate? Any COP or efficiency numbers?
- Answered live. The chart shows 15 months of data – before geothermal and after geothermal. The chart shows two winters and one summer. The chart is a bit deceiving because they were on a payment plan with the gas company. This means there is little change in the gas bill between winter and summer. The electric bill is high in the summer because the AC ran almost 24/7 to control humidity while the heat would run simultaneously to compensate for the overcooling.Annual operating cost savings is about 40 to 50% while being more comfortable more often. COP upon commissioning was between 5 and 6 for all systems. With variable speed equipment, the COP is variable every minute that the system is running. An annual COP has not been calculated.
- Could you provide a cost per ton? Also did they take advantage of any incentives?
- Answered live - There were no rebates available at the time of installation. The Orchard House is a non profit organization that cannot take advantage of tax credits. I would respectively decline from telling the public the cost of the system.
- Can Melanie explain how the savings are on the electricity bill? It would seem the savings would come from eliminating the gas bill and that electricity costs would go up by a lesser amount from running the geothermal system.
- Answered live. Please see answer for #3 above. Both the electric bill and the gas bill have decreased.
- Do you have a proposed payback period for this project?
- No. Payback was not the goal. Improved comfort, lower bills, ease of operation, and protecting the museum collection were the priorities. In order to calculate payback, we would need to know the cost of a new ‘conventional’ heating and cooling system. This information was not made available to us.
- Air Crete is a non expansion foam that may be the perfect solution for this building. It is a non -expansion foam that is installed with a tremi pipe every 16 inches.
- Please see response for #1 above. We were to assume that no changes were to be made to the thermal envelope.
- What was the energy supply to the attic water glycol?
- 20% ethanol for all of the units.
- Was an all-hydronic distribution geothermal system considered to heat & air-condition without having to install ductwork for either mode and to retain its heritage value relating to look & feel both inside & out while having maximum efficiency related to water distribution with small wattage circulators? Was the last distribution system forced air?
- Answered live - The last distribution system was hydro-air (complex). It was a ducted system with small hydronic coils inserted into each take-off. The fans would run continuously with heat being delivered to each room/zone by opening solenoid valves to deliver hot water to each coil. We opted for water to air package units for simplicity and efficiency. Water to air heat pumps are more efficient than water to water systems. As a company, we prefer water to air systems in general.
- Any noteworthy PR in the news or online? Is there a case study in addition to this presentation? (Same question for Larry.)
Answered live - There were several press releases and info on social media - Here is a link to the case study on the Town’s website:
Here is the link to a local press release:
- How did you dehumidify and cool?
- Answered live - The air conditioning inherently removes humidity. By dialing down the fan speed, the variable speed equipment was able to keep the summer humidity levels between the desired 50 to 55%. No special dehumidification equipment was required.
- Why did you choose a package unit for the attic, rather than a split?
- Answered live. There were no variable speed split units at the time, that we’re aware of.
- What a fascinating project! since demand fluctuates so much per what movies come out etc., did you develop target metrics per visitor-hour as functional unit? if not, do you plan to do so?
- Answered live - No we did not develop target metrics. We do not plan to do so. Occupancy was not the driving factor in this design – it is a very leaky building. You can see daylight under exterior doors and through the window frames. The building is dark brown with a due-south facing exposure. The building doesn’t follow any building codes or conventional design conditions. The size of the geothermal system was based on a combination of information: existing size of heating & cooling system, conventional design software, the existing duct work, the gas and electric bills, interviewing the property manager about how the space is used, and our experience.
- above question how did the attic air handler receive its thermal energy?
- Answered live. The attic unit is a package unit attached directly to the ground loop. The attic itself is heated unintentionally from rooms below.
- Isn't this a good example of how geothermal can eliminate greenhouse gas emissions even in a very leaky building?
- Yes! The gas line and gas meter were completely eliminated.
- How did the attic air handler receive colling? was there a compressor in attic?
- Yes, there was a compressor in the attic. Please see #14 above.