How would you do this one?

S Ebels

I've been wearing down pecils on this since 3:30 this afternoon and have a plan and equipment selected. BUT! I have been told by my better half that I don't know everything so I'm asking for the collective wisdom of the WALL to chime in with suggestions.

Here's the load we have to drive:

This is in a new dairy barn which presents it's own set of inherent problems but that's another topic. Let's just look at the system.

We have:

1. A 120 gallon indirect that needs to be at a minimum of 175* storage temp.

2. A 120K btu airhandler which requires 140 to 180* water.

3. 2,990 sq ft of poop melt for the cattle approach area to the milking parlor. (I caught this one in time to get a tube in the floor for a temp sensor.) 328,900 btu's

4. 2,160 sq ft of poop melt for a culvert and gutter taking the manure out to the pit. (Not so lucky on this one, there is no provision for a slab sensor so control is up in the air at this point) 237,000 btu's

5. A 720 sq ft area of radiant slab for the office, bathroom, employee room and vet room. 25,380 btu's at design

6. A 780 sq ft area of radiant slab for the milkhouse/utility room and the parlor itself. 156,000 btu's at design. Actual area of the parlor is 2,600 sq ft.

Some design considerations and problems. I was NOT involved with the initial layout of the underfloor tubing.

Item 4. They ran a 300 foot round trip, 1" pex tube circuit out to the manifold location for this. I'm told the loops running from the manifold are 350' long 5/8" tube. 14 of 'em. I don't think 1" pex is going to supply the flow (Calculated load of 237,600 btu's)

Item 6. The parlor is drastically under-tubed. The dairy supply guy/designer refused to put any tube in the cow platform which is the major portion of the total sq ft available. Hence, I'm thinking an air handler of some kind to supplement. The problem is constant maint involved in keeping the coils and fins clean in a very hostile environment. Looking for other alternatives here.

7. The dairy system design guy is using water cooled condensers for the milk cooler. He has a 1000 gallon insulated tank which water is circulated through for the condensers. I think it would be a big bonus to grab some of the btu's in there and dump them out in the floors. (I did get into the loop early enough to suggest that)

The system will be fuel oil fired. The poop melt, which is the bulk of the load, will only be needed probably 3 months out of the year. All of those areas are under a roof and the barn has sidewall curtains that are pulled down from November to April. It's not directly exposed to snow, ice and wind. We just have to keep the s--t from freezing on when it's really cold.

That being the case, you can see that 550K of the load is not there most of the year.

Here's the good part. Visualize a rectangular space 10' wide x 4' in depth x 12' in height. This is the space allowed for the boiler(s), water heater, piping, controls, all the circs, a 24 loop manifold, a 6 loop manifold, an 8 loop manifold, plate hx's for the floors, plate hx's for the heat recovery from the water cooled condensers, mixing device(s) expansion tank, etc. etc.

Please share your ideas freely. I have my ideas but at this point they are not cut in stone.

Weezbo

i am wondering some things.....

does the "parlor" have a trough to water and feed the cows ? does it have a railing or twoo to keep them from fighting over food and quieted down ?

chuck shaw

Item 4

Steve,

Could you use the 1" pex like a "mini-tube" injection system? That might help you out, rather than delivering all the water thru the 1", you could mix the temp remotely.

Just a thought,

Chuck

Mark Eatherton1

Man, what a crock of...

fecal laden water!

Steve, you've got your hands full with this one. In the same order your presented them,

1. Whats the hourly load on the DHW system? (Exclude preheat from milk cooling system in case it goes down, Consider the "FREE" btu's a side benefit, but don't depend on them) You probably have ZERO diversity on this load.

2. No problem, other than maintenance as you pointed out. Maybe you could consider some sort of "air washer" to reduce maintenance.

3. This load scares me. If it were just a standing melt system that would be one thing, but if it's as I suspect, there are rotary impact sprinklers in the area for the rough "udder wash", the short term load could be tripple what you're anticipating. The "carry off" effect of water rolling across your slab is much more substantial than you would think.

4. Same situation as item 3, watch out for the carry off load.

5. No concerns.

Re: 1" lines, at a 30 degree delta T, that works out to around 16 GPM. It'll take a pump with some pretty hefty cajones to push the snowmelt slushy there and back. I'll use Siggys Super Software and tell you what would be required in later post.

Re: Air handler maintenance, look into air washers. They will add humidity to the environmental air, but most parlors I've been in are humid anyway. Google "air washers".

Maybe radiant walls or ceilings??

Re: waste heat recovery, I think you'll find a problem with approach temperatures, and btu availability on this one. Consider it for DHW preheat, but don't try to stretch the btu's too far. The DHW loads of a typical milking operation are pretty considerable in and of themselves.

As for mechanical space, think vertical with LOTS of Uni-strut racking. Keep the obviously heaviest loads (storage tanks) on the ground. Boilers can be rack mounted and vertically stacked. Multiple stages will increase seasonal performance.

All I can say for them is it's a good thing they got you involved. Too bad it wasn't sooner...

Good Luck.

ME

Mark Eatherton1

Siggys SuperDuper Softwware results...

Looks like you will either need a custome pump that can generate 110 feet of head whilst pushing 32 GPM, or enough space to put four Grundfos 4375's in series...

Parameters as follows;

350 foot circuts of 5/8" PEX, 300 foot circuit of 1" PEX doing S&R, 20 foot of 2" copper in mechancial room, 40% solution of prop-gly and H2O.

There you be...

ME

Kevin Bouwman

S Ebels,

Boy does this sound familiar! I am a “dairy supply/design guy” who has been doing parlors, pipelines, and milk coolers for 22 years. I have been doing milking center water reclamation for about 18 years and radiant heat for 15 years. In all that time I have been in your situation far too many times.

1. How many BTU’s can your indirect soak up? From my experience, unless the parlor is smaller than a Double-6 and the milk hauler empties the bulk tank at least an hour after the pipeline is done washing, you are going to run SHORT of hot water. A 120 gallon water heater of any type with a storage temp of 175 is going to be delivering water temps below 160 degrees at the tap by the time half of the stored volume is used. If the rinse cycle and detergent cycle combined need more than 50 to 60 gallons of 170 degree water and ANY hot water is used out of the system ANY where else you will have a tough time keeping the vat temp above the 160 degree mark required when the detergent solution starts to circulate. If the system is larger than this, consider adding storage and a little recirculation pump.
2. Is the air handler for the parlor? If there is not any tubing in the cow decks then you will need to expect your supplemental heat source to do all of the work. The radiant in the pit floor will just keep feet warm. The heat loss in a modern parlor is hard to keep up with even when all the horizontal surfaces have insulation under them and heat tubing in them. It will help during the coldest days if your control system will let you supply hot enough water to get a 90 or 100 degree surface temp. I have done this successfully for the pit floor and the cow decks on past projects.
3. I have three poop melt installations in southeast South Dakota and northwest Iowa that all very successfully keep the slabs at 38 to 40 degrees with 25 BTU input per square foot and a supply water temp of 70 degrees. They all have 5/8 inch tubing in 200 to 250 foot loops; the newest one of them has R-7.5 under-slab insulation and the other two have none. This is much less than the snowmelt calculations would predict but because a system like this operates all season long with no wind we are only maintaining…never melting. When snow falls on a slab it is frozen and must have the latent heat supplied to melt it, when the poop falls it is 98 degrees and we just have to keep it from freezing. The cows each radiate 1000 BTU/h for the time they are in the pen and the building with its curtains does have SOME R-value. An R-value of 1 or 2 is an awful lot more than none and a wind speed of exactly 0 is much easier for the slab to deal with than even 5mph.
4. I have found that when utility rooms are zoned by themselves, the zone never calls for heat. Milk houses, especially small ones with outside doors, call for double the BTU per square foot that the office, bathroom, and break rooms do. This is mostly due to the infiltration that comes from a lot of foot traffic and ventilation.
5. While in-slab sensors are the ideal way to control poop melt, sensing the return water temp would work. My guess is that the culvert and gutter will lose less heat than the holding pen so if you controlled them both off the sensor in the pen you would probably get along just fine.
6. Using Siggy’s mini tube idea you could send 180 degree water through the 1” pipe to the manifold for the culvert, mix it down to the 70 or 80 degrees that the slab probably needs and send it back to the utility room close to the 45 or 50 degree slab return temp. With a 130 degree differential you can move a tremendous amount of heat with a very small gpm flow rate. If your boiler is the non condensing type you will need to make sure that it doesn’t see that 50 degree water directly. If you are going to use glycol in the poop melt, keep in mind that a glycol/water solution cannot move as many BTU per gallon as plain water can. To make up for that you will have to push the water around the system faster; if that isn’t bad enough glycol/water solutions are harder to push too. Using a given pipe size and loop length, you need considerably larger pumps on glycol systems.
7. Why on earth did the dairy guy not want any tubing in the cow platform? Forced air, no matter how that air is heated, is a huge maintenance pain in a parlor. It can not and will not produce anything remotely close to a comfortable work environment. This is going to be painful so brace yourself; the ONLY way, and the cheapest way (in the long run) to make this parlor somewhat comfortable is to chop those decks out, insulate with 2” foam board, lay down 200’ to 250’ loops of 5/8” pex on 12” centers, and pour new concrete. I am fully aware of the consequences of what I just said but know that if you do not do this you will WILL have parlor that is very expensive to heat and maintain and still cold, very uncomfortable, and maybe even, at times, icy. The only other alternative that has occurred to me is putting tubing in/on the walls AND the ceiling. I have never tried this but based on some of what I have read on the wall I think it could work. I have put tubing in the pit walls (in addition to the pit floor and cow decks) which greatly improved milker comfort in a parlor that has only a curtain between the parlor and holding pen.
8. I too, have installed many water cooled condensers and reclaimed the WATER in one or more ways, but reclaiming the heat is difficult to do cost effectively. It is simply not hot enough to drive an exchange. We usually use the water to supply cattle fountains, wash down pumps, and systems for flushing the parlor and holding pen floors.
9. In my new shop, I have a 6-loop manifold, a 4-loop manifold, a 7-loop manifold, a plate HX for snowmelt, two 90,000 BTU electric boilers and the controls compactly arranged and fully covering a wall 17 feet long and 9 feet tall and occupying about 2’ in depth. A 26 gallon indirect and a 120 gallon storage tank are setting immediately behind this wall in just the right place to keep the piping they require on the boiler side of the wall as simple as possible. They occupy a space 5 feet long x 6 feet tall x 2.5 feet deep. It is going to be extremely difficult to put everything you described in your space and be able to access any of it for maintenance.

Kevin

Kevin Bouwman

S Ebels,

Boy does this sound familiar! I am a “dairy supply/design guy” who has been doing parlors, pipelines, and milk coolers for 22 years. I have been doing milking center water reclamation for about 18 years and radiant heat for 15 years. In all that time I have been in your situation far too many times.

1. How many BTU’s can your indirect soak up? From my experience, unless the parlor is smaller than a Double-6 and the milk hauler empties the bulk tank at least an hour after the pipeline is done washing, you are going to run SHORT of hot water. A 120 gallon water heater of any type with a storage temp of 175 is going to be delivering water temps below 160 degrees at the tap by the time half of the stored volume is used. If the rinse cycle and detergent cycle combined need more than 50 to 60 gallons of 170 degree water and ANY hot water is used out of the system ANY where else you will have a tough time keeping the vat temp above the 160 degree mark required when the detergent solution starts to circulate. If the system is larger than this, consider adding storage and a little recirculation pump.

2. Is the air handler for the parlor? If there is not any tubing in the cow decks then you will need to expect your supplemental heat source to do all of the work. The radiant in the pit floor will just keep feet warm. The heat loss in a modern parlor is hard to keep up with even when all the horizontal surfaces have insulation under them and heat tubing in them. It will help during the coldest days if your control system will let you supply hot enough water to get a 90 or 100 degree surface temp. I have done this successfully for the pit floor and the cow decks on past projects.

3. I have three poop melt installations in southeast South Dakota and northwest Iowa that all very successfully keep the slabs at 38 to 40 degrees with 25 BTU input per square foot and a supply water temp of 70 degrees. They all have 5/8 inch tubing in 200 to 250 foot loops; the newest one of them has R-7.5 under-slab insulation and the other two have none. This is much less than the snowmelt calculations would predict but because a system like this operates all season long with no wind we are only maintaining…never melting. When snow falls on a slab it is frozen and must have the latent heat supplied to melt it, when the poop falls it is 98 degrees and we just have to keep it from freezing. The cows each radiate 1000 BTU/h for the time they are in the pen and the building with its curtains does have SOME R-value. An R-value of 1 or 2 is an awful lot more than none and a wind speed of exactly 0 is much easier for the slab to deal with than even 5mph.

4. I have found that when utility rooms are zoned by themselves, the zone never calls for heat. Milk houses, especially small ones with outside doors, call for double the BTU per square foot that the office, bathroom, and break rooms do. This is mostly due to the infiltration that comes from a lot of foot traffic and ventilation.

5. While in-slab sensors are the ideal way to control poop melt, sensing the return water temp would work. My guess is that the culvert and gutter will lose less heat than the holding pen so if you controlled them both off the sensor in the pen you would probably get along just fine.

6. Using Siggy’s mini tube idea you could send 180 degree water through the 1” pipe to the manifold for the culvert, mix it down to the 70 or 80 degrees that the slab probably needs and send it back to the utility room close to the 45 or 50 degree slab return temp. With a 130 degree differential you can move a tremendous amount of heat with a very small gpm flow rate. If your boiler is the non condensing type you will need to make sure that it doesn’t see that 50 degree water directly. If you are going to use glycol in the poop melt, keep in mind that a glycol/water solution cannot move as many BTU per gallon as plain water can. To make up for that you will have to push the water around the system faster; if that isn’t bad enough glycol/water solutions are harder to push too. Using a given pipe size and loop length, you need considerably larger pumps on glycol systems.

7. Why on earth did the dairy guy not want any tubing in the cow platform? Forced air, no matter how that air is heated, is a huge maintenance pain in a parlor. It can not and will not produce anything remotely close to a comfortable work environment. This is going to be painful so brace yourself; the ONLY way, and the cheapest way (in the long run) to make this parlor somewhat comfortable is to chop those decks out, insulate with 2” foam board, lay down 200’ to 250’ loops of 5/8” pex on 12” centers, and pour new concrete. I am fully aware of the consequences of what I just said but know that if you do not do this you will WILL have parlor that is very expensive to heat and maintain and still cold, very uncomfortable, and maybe even, at times, icy. The only other alternative that has occurred to me is putting tubing in/on the walls AND the ceiling. I have never tried this but based on some of what I have read on the wall I think it could work. I have put tubing in the pit walls (in addition to the pit floor and cow decks) which greatly improved milker comfort in a parlor that has only a curtain between the parlor and holding pen.

8. I too, have installed many water cooled condensers and reclaimed the WATER in one or more ways, but reclaiming the heat is difficult to do cost effectively. It is simply not hot enough to drive an exchange. We usually use the water to supply cattle fountains, wash down pumps, and systems for flushing the parlor and holding pen floors.

9. In my new shop, I have a 6-loop manifold, a 4-loop manifold, a 7-loop manifold, a plate HX for snowmelt, two 90,000 BTU electric boilers and the controls compactly arranged and fully covering a wall 17 feet long and 9 feet tall and occupying about 2’ in depth. A 26 gallon indirect and a 120 gallon storage tank are setting immediately behind this wall in just the right place to keep the piping they require on the boiler side of the wall as simple as possible. They occupy a space 5 feet long x 6 feet tall x 2.5 feet deep. It is going to be extremely difficult to put everything you described in your space and be able to access any of it for maintenance.

Kevin

Steve Ebels_2

Thanks Mark

I'm tired of watching the Colts kick the snot out of the Broncos and it's halftime so I thought I'd check in on this.

I figured this one would get your noggin noddin'.

1.The DHW load is not all that great. The wash system installed is supposedly able to do it's thing with minimal (comparatively) water use. I haven't seen the numbers yet but the dairy guy says an 80 gallon tank will suffice. I'm still going to recommend a 120. I'm keeping an open mind until I see some hard and fast GPM rates and how fast the tank has to recover.

2. Thinking of building a filter rack on the back of the AHU (simply a horizontal discharge hydronic unit heater) to help out the dust/fly/airborne dung factor. Not much else I can do.

3. I think I'll be all right with my calculation of 110 btu's/sq.ft. (see the post below) There is no system in place for udder prewash that I know of but I will definitely check.

RE: tubing size problem. I talked with Siggy this past week to A: order his software and B: see what he had to say about the situation. He said a minitube system running off the high temp side of the system should handle it and I agree. We'll make the control setup work somehow.

At this point I'm leaning toward proposing a single C/I boiler with a two stage Riello 28 burner. Main near boiler piping will be 2 1/2" copper. The boiler control will run the 2" mix valve for all the low temp circuits. (bear in mind that about 250K of the load for the poop melt is coming off the high temp side) I may add an additional mixer to give me a third (higher) temp for the office/parlor/vet room zones. It would help out the parlor a little, but most of the load in there is going to be the AHU's job. I do have one option for radiant there yet and that is the ceiling. I'm open to suggestions as to how I could get some serious heat out of that. By the time the AHU blows air the length of the parlor, it's going to feel cold even if I ran steam through it. The ceiling is slated to be covered with corrugated panels of vinyl soffit. I don't know how well that will transfer heat given that there will be a dead air space between the OSB and the actual surface of the ceiling. Lot's of question marks in my mind on that one. What do you think?

Steve Ebels_2

Kevin

Nice to have the voice of experience chime in here. The parlor is a double 12 side exit Alfa Laval design. Pretty impressive. All you see is stainless in there. Everything is behind SS panels. What brands of equipment do you sell and which is your favorite?

1. I share your concerns about maintaining the temp. I think the dairy code says the exit temp of the water in the final rinse has to be 160* or something like that. To me, that means some seriously hot water going in. (180*+?)
As I replied to Mark, I'm waiting to see some numbers before I make a call on this one. The tank BTW, is capable of transfering about 240-250K depending on incoming and delivery temps.

3. All my design programs call for a level 1 snow melt in this area to be driven at 150-170 btu's/sq ft. My gut feeling is that this is way high but I'd rather have too much than not enough so I'm going with 110. It will, as you say, likely be much less. Portions of the culvert/gutter are actually underground so I think that will be less than I've allowed for also.

6. I think we're all in agreement that a minitube is the only way to fly on this zone. The head and GPM for a single pump driving that much load would mean about a 2HP circ. Not something I'd like to pay the light bill on. Oh well, you work with what you have. The boiler has a shunt pump package for condensation protection. Yes there will be glycol in the system so the circs will be sized accordingly.

7. I don't know, but I have a feeling he was invloved with a situation where the platform temp was driven way to high and wound up baking on the manure before the end of the milking. I myself see no earthly reason not to heat that area as it's the largest floor space in the parlor. People don't understand how a properly controlled radiant floor works. Nor can they grasp how much heat a few tons of concrete can emit when hit with 20* air. I'm going to try for the ceiling yet. The walls are already in poured in place so we strike out there.

8. If I can determine that we have a good delta T to work with (floor return 70* vs holding tank 110* I think it would be feasible. If not, I won't recommend even doing it. Maybe for DHW preheat or the other uses you described.

Thanks for the input

Steve Ebels_2

Thanks Chuck!

Mini tube it is. It's the only feasible way to deliver that many btu's through that diameter tube.

How's that Testo stuff working for you?

Steve Ebels_2

Nope

No water, no food that I know of. They suck the milk out of 'em and turn 'em loose. There is a watering station at the entrance and the exit of the parlor if I'm not mistaken. They rarely fight, Holsteins are pretty docile critters unless they are scared, then just get the heck out of the way.

Weezbo

this is out of my area of gazing clearly into my crystal ball

were it it to have a feeding trough my thought would be to lay in some loops at that end of the cow:) on the otherside on the perimiter of the building laying in a few loops zoned and run at stiff temps to act as a heat wall would be a means of keeping the farthest regions of the buildings slab perimiter really hot.it would need insulation and to be poured though. the 1" run will carry lot of btus if your puting in a header with a bypass off the 1" or if you dont have a liking for that idea zone the header run two more 1" through the utilidor use one for high heat one for lower temp .

Kevin Bouwman

Steve

I sell BouMatic equipment and it is definitely the best kind.

1. To properly wash a system you need 110*-130* pre rinse. Next, is the detergent cycle, this requires the vat temp to be about 160*-165* when full and circulation starts. It must be over 115* when circulation finishes. The subsequent rinses are usually cold water but may be 100*-110* in some cases. If the fill valves are sized properly it should take 5 minutes or less to fill the vat each time and the detergent fill will start as soon as 5 minutes after the rinse fill completes. A double-12 parallel parlor (the shortest kind) with one loop of 3” stainless steel milk pipeline (the simplest and minimum arrangement) will require that the vat be filled to the 90 gallon mark for each cycle. If there is a separate pipeline for each side of the parlor you will need 125 to 140 gallons per cycle. The hot water tap will have to be able to still flow at 160* or greater after having run at 20 GPM for 10 minutes. I have large bruises on my forehead from beating my head on the wall trying to figure out how to keep systems clean with not enough hot water. Add 50% to this calculation for all the things they do not know they will be using hot water for. Do NOT count any desuperheaters in your storage or recovery calculations. Either they recover heat to save operating cost or they store hot water…they CANNOT and WILL NOT do both 24/7/365.

7. In the double 12 dairy in South Dakota I mentioned in my email to you I run the cow decks and the pit floor at a 110* surface temperature with no problems what-so-ever. The infiltration loss is so great that I try to radiate heat at the operators to balance the heat they are losing to the air and to the wall of glass at the front of the parlor.

8. For the water cooled condensers, if the head pressure control is set at 250PSI like BouMatic recommends for its tanks, the refrigerant temp will be no more than 116*. By the time the refrigerant is subcooled 10* or so, the discharge water will be at most 100*, and the storage tank temp will be 90* or less.

Christian Egli

Convert all to steam... well, maybe here are other ideas,

I have been exposed to greenhouses where heat is very simply radiated from steel pipes on the ceiling. Just 2 inch pipes spaced about every 4 to 8 feet.

Hot water flows in these pipes and can deliver enough heat to make it a hothouse. Hot water is always on a reset system.

No maintenance problems at all, nothing to clean. I imagine reflectors could make it even better.

I have also worked on industrial buildings with steam fin tubes hanging from the ceiling. These provide very nice comfort.

With an application like this, is there room in the budget to add a cogeneration unit and make heat and power together for added savings in operating costs. I imagine they will have some kind of back up power generator anyway, why not run it for more than just emergencies?

I always imagined dairies running with steam everywhere. That would be a dream job.

Happy cows make more milk.

Thanks for the nice post

Christian

Floyd_7

Steve, Kevin's got it right...

my experience is that you will need much less BTU's for the poop melt then you think and will need much more btu's and storage for the hot water than your thinking. The (Herd) effect will help out the poop melt more then you know.....if the barn s closed up at all the temps. will stay well above the outdoor temps. making your design temps much higher.
Parlors, also will benifit and if the people doing the milking don't mind it being a bit cool to start the parlor will warm up during the milking time. Then all you need is to keep things from freezing in the (off) times.....makes a heck of a difference when your designing for 40 instead of 70.
Farmers around me a cheap and don't give rip if they are starting out at 40.

I have had to upgrade a hot water tank at my exspense already.....wasn't the washing the parlor that killed me... it was washing the bulk tank. Trust me you will need some serious hot water production........
Floyd

Steve Ebels_2

Still up thinking about this one.

Been in bed and couldn't sleep. The last parlor I did was a 32 cow rotary platform and I installed a pair of 120gl storage tanks in series fired with a dedicated boiler. Those folks haven't run out of hot water. Ever.

I still haven't received any firm numbers on the draw for each portion of the wash cycle on this one but I'm with you guys. An 80 gl tank is a lightweight when it comes to washing milking equipment unless you're able to dump about a million btu's /hr into it.

Kevin Bouwman

I have a twin Double-8 parlor (32 unis total) with one 100 gallon 199,000 BTU water heater and one 100 gallon 75,000 BTU water heater that are plumbed in series and fed by a 120 gallon desuperheater. Even with this capacity the dairyman needs to be sure he doesn't wash either of the bulk tanks (8000 gallon each) from 1 hour before washing the pipeline through 45 minutes after washing the pipeline. This is often a bigger inconvienence than it sounds.