You might also consider solar hot water and also wood/wood pellet.  As your in the NW you need to use what is abundant and local to keep costs down.

CH

Heavy heat load. I am suspicious that it may be high.
Among solutions would be radiant loops embedded in soil outside the firestone liner.
This could have heat provided by any water heating system including solar, wood boiler, geo... the rest of the green house can also be heated by radiant or hydronic fan coils.
A professional design is in order.
Millions of BTU's can be provided by geo, but not without much upfront $$$.
Wheter it's worth it will take more calculation than you are likely to get for less than several thousand dollars.
A good ME or designer will likely save you many times your investment.
Good Luck,
Joe

I can't really picture the relationship between the raceways and the greenhouses or the purpose of them, but this strikes me as fundamentally similar to an indoor swimming pool. I too am skeptical of the 600 kBtuh load if for no other reason than that the thermal mass of such a pool is high so one likely needs only meet the average daily low temperature rather than the 5 AM temperature.

I suppose a pool teeming with shrimp needs quite a bit of oxygen mixed in or air above, so that figures into the thermodynamics

That said, the demand for such a large amount of low grade heat cries out for a thermal host such as a paper mill or power plant - facilities that endlessly reject heat into the surrounding air or water.

Finally, if I had to pick a climate suitable for maintaining large pools of water at 82F 365/24/7 it might well not be in Washington state. Momma nature keeps her shrimp in mild southern climates, but they ship easily worldwide. It may make more environmental and economical sense to move the shrimp to the climate rather than the other way around.

As Joe said, since you aren't an engineer, hire one with demonstrated expertise in the thermodynamics, hydrodynamics and psychrometrics this project certainly entails.

Air source heat pump pool heaters are becoming popular for heating swimming pools. That in conjunction with a propane boiler and pool heat exchanger may help reduce heating costs.

ashp pool heaters are a new inadvertant area of mine (called the rep with a question to help a friend and asked them who their local service rep was..."how 'bout you" was the reply).
Their cut out is relatively high at 45* So they are not great for winter heating in heating dominated climates.
They also aren't terrifically hearty (for year round use) but are relatively inexpensive/ton at about $500 installed.
COPs are relatively low (~ 2ish).
I'd be reluctant to recommend them for high workloads in any app.
j

600,000 BTU requirement is based on the area of the raceway and is also based at the lowest temperature during winter time.  It is always good to go a little extra then under when it comes down to the heating as the temperature of the water has a huge effect on how the animals will grow.

The reason why I have to choose PNW as a destination for such is for marketing reasons because we will be selling the products live and it is important that I can get to my immediate market in a timely fashion to command live pricing.

And in a nutshell, it is alsmost like a swimming pool that I want to heat, but coming back to the question do you all think the concept to drill vertically and tap into a heat exchanger or in floor radiant heating type set up would work?  If so, how deep do you think the drilling is requried to meet my requirements?

As for solar heting, I am worry it is not reliable because we do get a lot of glommy days in the PNW, and not sure if it will meet my needs consistently or not.  But I will look into that a little more in details.

Lastly, I am also thinking of hiring a geothermal engineer to do some pre-consultation before I makemy purchase on the property, does any one have good referrals in the PNW?  Thanks again for everyone that is chiming in.

Ken

Can you find someone who has waste heat and build next to them? Say a data center (very reliable) or a factory?

.

Datacenter idea may have merit, though producing 82 F in midwinter would hurt their efficiency over what is available to them in winter - maybe offer to pay for the differential COP.

Absent a thermal host, first cost for a geo system producing the required several hundred tons of heating will be very high. It is likely that the system would benefit from some value engineering, in other words, size the geo to meet only 80-95 % of the load and rely on propane for the rest.

This application is way beyond the expertise available here - while I would be fascinated to be in on such a project, I can only write in generalities about circumstances unknown to me 3000 miles away.

The PA Fish Commission has a large scale fish hatchery in Linesville, PA that is doing exactly what you propose. A hydrogeologist sited several high-yield 200+ gpm wells installed in areas with shallow groundwater. They use portable water to water heat pumps year round to regulate temperature in their many large indoor tanks. It is very cost effective and scalable and has been running for a good 20 years. Look at your groundwater quality, quantity, and depth. Closed loop would be cost prohibitive but open loop works great in these applications. I'll try to find more info as we were only involved due to minor heat pump repairs and some injection well scaling issues. Actually looking at your local geology you are in a broad alluvial valley close to the coast which will likely work well for high yield open loop wells (as long as salt water intrusion permitting isn't an issue). If you have access to the Nooksack river or another body of water you may be able to use that water instead of going with wells.

Down2Earth,
have you any sense of the btu load?
j

I take it that lots of light is needed for something? Not having so much glass would greatly decrease heat loss.

I thought 600K btu sounded high until I tried some numbers and got about the same. I suspect you need nat gas, passive geothermal, waste heat or a warm climate to make your business work.

Gentlemen, thank you for the thoughts & replies again.

Down2Earth, you mention the fish hatchery in PA, I tried to google it but I could not find any thing in relates to the geothermal system they have in place, do you have any info in private or links you would not mind sharing?

For my application, I think closed loop is probably the only way for me to make this happen. If it was open loop that would mean I have to discharge the water to the surface, and the volume to be discharged is quite significant and I need a really big dugout pond for it to infiltrate into the ground.... am I correct?

And 600,000 BTU is about right for each greenhouse structure and I believe with the proper insulation or heat conservation I should not require that much but then it is always to go 20% over then what I need rather than running short.

And someone mention airsource heat pump, can someone please help me understand how this may be applicable?
Thanks again for the suggestions and help. Cheers.

Posted By kcphuah on 06 Sep 2010 01:26 PM
Gentlemen, thank you for the thoughts & replies again. 

1) If it was open loop that would mean I have to discharge the water to the surface, and the volume to be discharged is quite significant and I need a really big dugout pond for it to infiltrate into the ground.... am I correct?

2) And 600,000 BTU is about right for each greenhouse structure and I believe with the proper insulation or heat conservation I should not require that much but then it is always to go 20% over then what I need rather than running short.

3) And someone mention airsource heat pump, can someone please help me understand how this may be applicable?
Thanks again for the suggestions and help. Cheers.

1) Volume discharged around here is generally ~200Kgal/yr for heating and cooling, but there are many factors. Discharge could vary as well depending on soil etc.

2) 600K can't be "right" and 20% oversized at the same time. Geo best serves when designed to cover the bulk of the load, not load + (in heating dominated climates). Alittle bit extra to cover the odd extreme could cost considerably more than decades of auxiliary electric or propane.
The source of some debate here, many share the philosophy that geo serves best when designed to cover 92%-98% of the load, not 100+%. No one hover (to my knowledge) has ever suggested an extra 20% of capacity is appropriate.

3) There are air to water heat pumps. Used for pool or domestic hot water. I don't think they are a good fit here.

j

Saw this while browsing one of the Geo manufacturer's sites.  Thought it might be a similar type of application.

http://nordicghp.com/images/stories/PDFs/Commercial-Case-Studies/aquaculture-fish-hatchery.pdf

Cool link and pdf.

82 F in the PacNW is going to be a tough load nut to crack, economically, anyway - those shrimp might be pricey.

Posted By engineer on 11 Sep 2010 10:22 AM

82 F in the PacNW is going to be a tough load nut to crack, economically, anyway ....

I was thinkin' the same. Has the OP considered working with a different species of shrimp?

I am really interested in your project, I am in the development stages of a similar, yet smaller project.

We are installing 30kw of solar pv on dual axis trackers to help power the green house. Our initial plan was to grow out the prawn in tanks.

I would be interested in exchanging ideas, as we would be in two completely different markets.

give me a buzz at my emai [email protected] , I don't mind discussing ideas and I am not worry about my ideas being "stolen" as the demand of quality shrimp is so huge, and if information exchanged can help each other by gaining more knowledge and avoid pitfalls, it is a win-win for every shrimp farmers.