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geothermal pros here?

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Craig R Bergman
Craig R Bergman Member Posts: 100
in THE MAIN WALL
The EW series needs a larger loop field.
Up size your field one ton above the Geo's ratings.

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  • GW
    GW Member Posts: 5,137
    geothermal pros here?

    I'll be starting a building soon for my business. Anyone know the slickest way to use the geo radiant floor AND ductes AC? I'm dealing with Waterfurnace; just don't know what unit will best apply at this moment.

    Gary

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  • rumn8r
    rumn8r Member Posts: 105
    Synergy 3

    I've used numerous of them and had only one compressor failure/issue.

    Design around low water temperatures, say max 110 degrees F. You can get 120 degrees F out of the unit, at a realtively low COP depending upon EWT.


    http://www.waterfurnace.com/content.aspx?section=residential&page=prod4


    Congratulations for doing the "Right Thing".

    Attached is a barn we did that has a 5 ton Syn 3 and a 5 ton EW doing heating and cooling. This barn originally was built on the banks of the Ohio river, and was disassembled and transported to the plains of Colorado where it was reassembled using SIP construction, and is now being heated and cooled using GSHP technology. If it works on his barn, it'll work on yours!

    ME
  • GW
    GW Member Posts: 5,137
    me

    any pics of the mechanicals? Did you modulate the radiant? Thanks for the tips.

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  • GW
    GW Member Posts: 5,137


    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    gary@wilsonph.com
  • Singh_2
    Singh_2 Member Posts: 20
    not a geo pro

    but everything after the heat pump is pretty much typical piping.
    Take your radiant off your buffer tank, maybe have those loops controled
    with OD reset, .
    Yes do a heatloss and design for >120* supply temps.
    For ac, run the chilled water to coil, insulate!!

    Also look at Econar systems, they are designed for cold climates like in New England. Lower EWT with higher COP. They are out of Minnesota.
    They should have drawings available, also look into IGSHPA , good info there also.

    Are you looking into vertical or horizontal loops?



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  • rumn8r
    rumn8r Member Posts: 105
    What Singh Sung...

    Treat the downstream distribution just as you usually would. I get the best overall comfort using non electric TRV's on the point of use controls.

    ODR is an option.

    Instead of doing a seperate DHW preheat tank and a buffer tank, we incorporate both into one with the TurboMax tanks.

    Nice large tappings, low pressure drop on the hydronic side and excellent heat transfer characteristics for the DHW preheat. If you go this route, and your DHW load is high, you probably don't need an ODR. If no DHW preheat, then go with the ODR, but control the heat pump. You'll get a higher seasonal COP.

    As for cooling, the Syn 3 is made for air cooling direct, not via FCU's. They (Water Furnace) do make some reversible water to water units, but in your case, based on your original post, I assume you wanted to move air for the AC side of things.

    ME
  • GMcD
    GMcD Member Posts: 477
    Radiant cooling too

    Why not harness the geo system for radiant cooling as well, to knock down the total cooling capacity from the air system? The first step is to design as high a quality of envelope as possible,with some good solar shading so you can minimize the cooling loads and try to get a balanced heating and cooling load profile over the year so you don't have to select the geo system for the worst case heating dominant or cooling dominant load. This also lowers the total cost of the geo system and heat pump sizes too, so $$ spent on the envelope will reduce $$ on the heating/cooling system.
  • GW
    GW Member Posts: 5,137
    go geo

    Singh, we're doing two vertical bores. I'm going for 5 tons.

    The radiant will heat the two large shop areas (about 50 x 40) and I'm on the fence on how to heat the office space...I may run the same radiant system, but because of the relaxed temperatures (I'm only going to shoot for 50* in the shop areas... the techs can keep their coats on!) in the radiant system I may add some Euro rads to nudge up the space heating needs for the office area (about 50 x 40 as well, but there are bathrooms, halls, closets, etc in this figure)

    Mark, I didn't know the EW series could perform both heating and cooling duties without a little conversion action. I'd love to use the new Envision for the air side, that thing rules. Is it possible to have one pump station and two HP units, one being the EW and one being the Envision? I need to chat with Waterfurnace's design guys. I get the hint that radiant is not their strength.

    When you say I could use Outdoor reset, can you explain this a bit more? I'm new to geo, so I'm sure I'll come across as a newbie here. How would the ODR control know how to modulate the temps? Or, is it one temp coming out of the HP and an ODR does some basic mixing on its way to the radiant system?

    Do, to clarify, I need hot water for the shops and I need to blow cold air for just the office area in the summer. That's why I posted the question; it's like I'm building a duel purpose animal here.

    Gary


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  • marc
    marc Member Posts: 203
    Geo

    I thought that 1 vertical hole at 200' in depth generated about 1 ton of energy, if you are needing 5 tons you would need minimum of 5 holes, we reset the tank temperature, if you reset after the tank with a mixing valve then the geo always maintains 120 h2o in the tank. Marc
  • rumn8r
    rumn8r Member Posts: 105
    pump and dump...

    Only requires 2 wells. It will require some pretty good flows to be able to handle the 5 tons of load tho...

    And yes Gary, we have done both, water to water, water to air/water on one project. Here in Colorado, the AC loads are typically 1/2 of the space heating loads, so the Syn 3 can do both, the AC and heat water (not at the same time).

    ODR is applied to the buffer tank temperature if preheating DHW is not a big priority. By changing the required supply output temperature, the COP of the heat pump is higher when the required FINAL temperature is lower.

    Otherwise, as Marc pointed out, you maintain the buffer tank at a fixed temperature and then use whatever method tickles your pink to mix down to the RFH loads.

    The Envision is the bees knees. It uses a scroll compressor with 2 stages. Thats where it gets the COP of 5. During part load conditions, it can run at half compressor output. Things, they are a changin' fast. Gotta run just to keep up.

    ME

    ME
  • GW
    GW Member Posts: 5,137
    bore

    I'm new at this. Just the other day I was at a Waterfurnace meeting and there was chat about feet per ton and such. Are you saying 200/ton... what size piping?

    My job will be two holes at 350 each with 1 1/4" pipe.

    Gary

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  • GW
    GW Member Posts: 5,137
    ME

    I'm still confused, it makes sense to me that the COP will be high when the HP temps are low, that's pretty basic. But when you say "final" temp, what do you mean? The HP doesn't really know the radiant is being mixed down after the tank does it? So if the HP outlet temps are not being modulated, how does it get more efficient in milder weather? I must be missing something here.

    I will not be using the geo for DHW.

    Thnaks,

    Gary

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  • Singh_2
    Singh_2 Member Posts: 20
    bore holes

    Yep, That's what I'm told also per ton 200'/ton closed loop system. Grouted with bentonite, bore holes 3" in diameter, good luck with that, I can't find a driller who is equipped for that, and they all want to drill 6" holes and charge me big bucks, NOT! I'd rather do horizontal, in your case a 5 ton slinky config will use about a 24'x80' plot of land.
    Gary the tube is 3/4" in the holes, header pipe id 1 1/4 piped reverse return , with the last two header tee's reduced to 3/4" to aid in air purging.

    Mark, I'm looking at doing a job this spring, I can't use the dual air/hydronic HP. Do to no room, basement or attic. I'm thinking radiant in slab and Hi-V for cooling Does waterfurnance have just water to water, what are the specs?




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  • Luke Lefever_3
    Luke Lefever_3 Member Posts: 38


    Mark is this what you meant to say?

    "And yes Gary, we have done both, water to water, water to air/water on one project. Here in Colorado, the AC loads are typically 1/2 of the space heating loads, so the Syn 3 can do both, the AC and heat water (not at the same time)."

    We use desuperheaters frequently in WSHP installations to do A/C and heat water simultaneously.
  • rumn8r
    rumn8r Member Posts: 105
    Luke...

    We've never done any desuper heating with our systems. If DHW preheat is a concern, we set a tank to do just that, and set an auxilliary down stream of that tank.

    In my mind, if I'm going to go to the torubles of setting a tank for DHW preheat, I want ALL the btu's I can get, not just the desuperheat potential.

    Now if AC were more of a load then it is around here, and I had a substantial, continuous DHW load, then desuper heating would probably make sense.

    When not using the desuper heat function, the heat pumps can only do one function at a time. Either heat or cool.

    ME
  • Luke Lefever_3
    Luke Lefever_3 Member Posts: 38


    Gotcha'. I didn't process the point you made about substantailly lower cooling loads. Not that many "free" BTUs to gather from the envelope. Our cooling loads are somewhat larger, and my logic is to try to capture all the "free" energy possible, rather than dump it in the ground.

    I follow you now, Luke
  • rumn8r
    rumn8r Member Posts: 105
    Gary, by final temp...

    I mean the temperature you are looking for from the GSHP. If DHW preheating is not a requirement, then treat the GSHP just like you would a MOD CON boiler. Do a full reset on it and your COP will be as high as it can be for the majority of the season.

    If you were doing DHW preheat, then you would always want to maintain the buffer tank/DHW preheat tank at the maximum allowable temperature, of 115 to 120 degrees F. Or if you are doing other loads, like heating a swimming pool and or hot tub and idling a snowmelt system, which we are in some cases.

    If you have a dual (hydronic heating and FCU cooling) load system, you can have a chilled water buffer tank for providing chilled water to the FCU's, and a hot water tank for DHW preheat/space heating needs.

    And once again, if properly designed, installed and operated, you could have an ODR on the chilled water and again, raise the COP or EER during the cooling season.

    A word of caution about VBH and slinky loop pits or HBT's. As with anything hydronic, we MUST know our limitations. The rule of thumb number of one VBH per ton @ 200 feet in depth WILL get you into trouble under certain soil/moisture conditions. I leave that work up to a geological professional. Dirt is not my bailywick.
    Hydronics is.

    Dirt has many different faces, and depending upon the soil make up and moisture content, transfers heat differently. I have been out to many problematic systems where the installer "rule of thumbed" the geo loop, and the systems are freezing up under duress load conditions.

    My suggestion to anyone interested in becoming a GSHP contractor is to join the IGSHPA or GHPC.

    Google those two acronyms to see what's up. They too are interested in seeing things done right so that this infant industry doesn't get trampled into the ground by runaway contractors jumping onto the energy conserving band wagon.

    And by the way, 115 degree F water does not work well in stapleup applications. As a matter of a fact, I prefer to use WarmBoard or concrete whenever possible when working with geo.

    ME
  • rumn8r
    rumn8r Member Posts: 105
    Singh...

    The EW series sounds just like what you're looking for.

    http://waterfurnace.com/content.aspx?section=residential&page=prod3

    You will still need a buffer tank at 1 gallon per 1000 btuH capacity. So for a 5 ton unit, you'd need a 60 gallon tank. Their unit is nice and compact.

    Also, watch out for their output numbers. They don't work as well making heat as they do getting rid of it...

    Be sure and read their performance charts. It may push 60 K btuH down the hole, but when trying to drag the btu's out of the hole, it is significantly less than the 60 K btuH, unless of course you're building on top of a bubbling hot aquafer...

    ME

    ME
  • Craig R Bergman
    Craig R Bergman Member Posts: 100
    I would leave...

    > I'm new at this. Just the other day I was at a

    > Waterfurnace meeting and there was chat about

    > feet per ton and such. Are you saying 200/ton...

    > what size piping?

    >

    > My job will be two holes at

    > 350 each with 1 1/4" pipe.

    >

    > Gary

    >

    > _A

    > HREF="http://www.heatinghelp.com/getListed.cfm?id=

    > 368&Step=30"_To Learn More About This

    > Professional, Click Here to Visit Their Ad in

    > "Find A Professional"_/A_



  • Craig R Bergman
    Craig R Bergman Member Posts: 100
    I would leave...

    the loop field to the pros. Do NOT attempt "rules of thumb" because it will come back to haunt you. When we went through IGSHPA's training, about half of the three days were about DIRT! We knew right then and there, Geo loops were not going to be installed by us!! Like Dirty Harry says..."Man's got to know his limitations!"

    If you are doing a "Pump and Dump" system be sure to check with the DNR. Most states limit what you can do with ground water.

    If you are doing a closed loop...Two vertical bores will not be enough for a five ton system. For each ton of heating and cooling required, one loop is required. How much loop is required per ton? That will depend on the type of soil,or rock,the loop field will be in. Here in Cedar Rapids, Iowa we "NORMALLY" need 700' of pipe per ton for a slinky. 400' of pipe for a horizontal bore and 300' of pipe for a vertical bore. Slinky's are set in a trench 6' to 7' feet deep, 4' wide and 100' long. Horizontal bores are set 20' down and 200' long. Vertical bores are 150' deep.

    Our looper just tore out a loop that was designed with rules of thumb by a company new to Geo. A five ton loop cost the home owner about 8K to replace (about 2K more than it should have cost) plus the cost of suing the original contractor. The system would not cool the house because there was not enough loop in the ground! Around here it takes about twice as many BTU's for heating compaired to cooling so you can guess what was going to happen when the Geo called for heat!!!! They were very lucky this showed up before the frost set in.

    Bergy
  • Brent_2
    Brent_2 Member Posts: 81
    well

    In our area (SE Pa) 150' of vertical borehole per ton of cooling is what we use for residential systems. For a water/air system you can make up the heating difference with a small amount of electric heat. Most people turn the electric heat off at the breaker and never turn it on. Desuperheaters are a great option especially if you pipe them to a seperate tank to preheat the dom hot water.
    We have done several water to water heating systems where we vary the temp in the storage tank based on the outside temp. We also did 1 job where we made chilled water in the same tank in the summer. This was piped to several small blowers.
    I design the tubing layout for a max water temp of 120°. We use ClimateMaster equipment.
  • Singh_2
    Singh_2 Member Posts: 20
    Rules of dumb

    Agreed , do the math before or have someone like the manufacturer do it for you.
    However, for a 6 ton or less residential you are covered with a loop per ton scenario. Since you are in new england size for heat you will be over for cooling by default. But choose the right equipment, Econar's are designed for heating loads, with a larger heat exchanger. I looked at the waterfurnance, seems they do well for cooling, leaving you short for heat, and having you use back-up.
    I would be cautious with the pump and dump two bore holes only.
    And Craig is right , the vertical stuff goes to the well driller, he the one that the state allows to dump or pump out of the ground.
    I went down to stillwater, o.k also pretty much much of igshpa training was good, when it came to dirt, informative , but left a lot of wiggle room for residential systems. Much different with large commercial systems, then you are talking about in-situ testing and the whole she-bang.

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  • GW
    GW Member Posts: 5,137
    pump and dump?

    who in the wide world of sports injected this into the conversation? This is closed loop vertical bore, grouted head to to toe. Thanks, Gary

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  • rumn8r
    rumn8r Member Posts: 105
    I did...

    because you said 2 wells on a 5 ton system:-) And the ONLY way you're going to get 5 tons out of a 2 well system is to pump and dump...

    Some people are doing it. I'm aware of a project in Nebraska that the farmer is using water off his irrigation well, running it through FCU's for "free cooling", then running it past his GSHP then dumping it into a pond he built outside his house for his swans...

    Doesn't seem like a real efficient use of a precious resource to me.


    ANd another thing that bothers me about these manufacturers literature is their statements about not using any fossil fuels for the operation of their system.

    That statement would be true if we were 100% nuclear electric powered, but they're killing more dinosaurs back at the electrical plant (natural gas and coal) then they are nukes these days...

    No...?

    ME
  • Singh_2
    Singh_2 Member Posts: 20
    Gary

    I guess someone assumed with only two bore holes on a five ton system it would have been a pump and dump.
    700' of exchanger surface area with a five ton system seems wrong.
    A bore hole per ton is a more common approach.
    But then again, like I said at the top of my post, I'm not a geo pro.

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  • GW
    GW Member Posts: 5,137
    sorry ME

    It's my newness wearing off on you.

    I'm really getting some conflicting news; i was told 125 to 140 ft/ton for vertical closed loop; obviuosly I'm seeing this is way too small.

    I hear the real deal... know your soil. Well, this is my persoanl building and by gosh I think I'll bite the bullet and "wing it" without doing 300' of dirt sampling.

    The driller is coming in a week or so. We recently discussed 3 300 foot holes with 1 1/4". Still too small? If I need to go up I'll call him one more time; he's getting used to it! Thanks all my experienced geo friends! Some day I will rule the geo horizon! For now I'm just the newbie.

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  • GW
    GW Member Posts: 5,137
    my fault!

    please comment on the latest guess of 3 300 ft holes!

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  • [Deleted User]
    [Deleted User] Posts: 43
    Not a problem...

    and it is entirely possible that in your area, with your soil conditions, and over a moving aquafer, that those well dimensions might work. But here in Colorado, you'd be in serious trouble.

    That's why I leave the "DIRTy work" to the professionals...

    As a possible option, there are what are known as well drillers logs, required by our state to be maintained and reported to the Dept of Natural Resources. THese give a pretty good description of what drillers in your area run into, but like anything in the world, their accuracy DEPENDS and can vary greatly over short distance.

    Don't forget to "Call Before You Dig" Big fines here in Colorado if you hit another utility and DIDN'T call.

    Lastly, there is a firm called Sound GeoThermal (www.soundgt.com) who does ground loop designs. I've not used them but have talked to people that have. It would be my suggestion that you give them a call and get their advice on how many wells and how deep you need to go. Nothing worse than coming up short and having to dig deep to rectify the situation.

    ME
  • Singh_2
    Singh_2 Member Posts: 20
    no problem


    Also think about building a purge cart(with good size pump) to pump out those loops and add glycol.
    From what I hear a lot of poor loop performance is due to air. And a manufacturer told me 3/4 is all you need into the holes, they then go into a 1 1/4 header. 3/4 can transfer just as well , and keep pumps small and price down.

    Good Luck , take pictures and share our experience when the time comes.

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