A call I recieved yesterday from a spectator here asked for help in strategies to heat a horse barn (loosely 5,600 sf with 10' ceilings). Looking at water to water (as forced air kicks up too much dust), he's been told that with dirt floor stalls, the cement down the cetral aisle did not offer a large enough foot print to adequately heat the space.
I know what i suggested, let's see what you guys come up with.
Joe

Water to water geo with radiant tubes in walls and / or ceiling springs immediately to mind. Wall tubing would have to be behind very sturdy paneling or above height where cranky horses' hooves hit walls, though an equestrian I am most assuredly not...

I'm even less than engineer. If I had a suggestion it would involve a glue factory.
What the chances you could even really keep the heat in with barn doors?

What I had in mind was to bury radiant tubes under the dirt stalls. While heat migrates through earth (as any geo guy can tell you), placement of insulation under and around an envelope (say an earthen stall floor) will make "up" the path of least resistance.
Recently I studied geo options in a "hoop house" for a co-op farm in Lansing. We had to place the radiant tube fairly deep to avoid direct impact on seedling roots, other than that damp earth was a better convector than concrete (kind of like stone vs damp soil).
The unfortunate part as always; you can't get a much more expensive install than radiant + water to water geo.
J

There's the expense and heat transfer possibly working against you - Even if perimeter and area beneath tubing is well insulated there is still the reality that enough heat must move through a thick layer of dirt to meet the load. The load may be less since horses presumably don't require the same ambient we do (or do they?). The barn may be leaky and poorly insulated.

You'd have to determine the load and the r value of whatever thickness of damp dirt the tubes would be beneath.

If memory serves, a buddy of mine charged with mucking out his family's horse stalls finished the job by spreading a couple inches of fresh wood shavings - probably a very good insulator. It seems to me geo would be a poor fit for the barn.

I think it's kind of sad that these horses can have a heating system, but a number of people will be dependent on aid to keep their houses heated.
Nothing against Joe, if he doesn't do the job someone else will, and then Joe might become one of those people unable to heat his house. The critters seem like an antiquated expense to me, but apparently the people that have them really love those walking glue factories.

My fault for not mentioning it before, but the customer here is a full time breeder/trainer/seller of thoroughbreds. As it is their business, not heating the barn would make no more sense than an unheated PetSmart.
Engineer, it is true that after cleaning the stalls, you would throw down straw or some other absorbing material (my first job was working as a pilot - that's spelled pile it- so I'm well aware of the process). As an added twist, the building owner has rubber mats that he would throw in the stalls, so we have that insulation to deal with.
All we can do is look at what's available to us, get out the cost calculator and see what makes sense.
It is true that geo will be an expensive way to heat the barn, but not necessarily more than everything else.
J

I would think radiant in the ceiling powered by geo heat pump would be a perfect way to heat a horse barn. Radiant ceilings work great and there is nothing in a horse barn to impede the radiant from the ceiling. As you pointed out radiant in the floor of a horse barn has many difficulties.

Horse people don't want blowing air (horses are suprisingly sensitive to dust) or flames in there heating system so radiant heat tied to an electric boiler or heat pump is perfect. As far as operating cost - geo should be cheaper to operate than anything else. As far as up front costs, the leakier the building the faster the geo will pay for itself so again a barn seems perfect for geo.

If the loft above the ceiling will be used for hay storage that will provide additional insulation to drive the heat downward.

I would recommend the use of capillary type radiant ceiling found at www.bekausa.com . It takes a different type of installation than we're used to here in the states, but only it only requires 90 deg. F. water or so to heat a structure. It can also be used for cooling.

The biggest challenge I've seen with it is the actual installation. It basically needs to be plastered in to a ceiling. Most people in the US, if not all, don't plaster anymore. We use sheetrock. Of course, one way is to sandwich it between 2 layers of sheetrock, just like they used to do with electric ceiling radiant heat.

This stuff is made of HDPE pipe, as I understand, too.

Like the ceiling ideas, there are imbedded osb or aluminum panels as well if not plaster. Was just speaking with a plumber (curiously also Greg J.) who has experience with these applications. We also discussed the probability that hot floors would be a turn off to Mr Ed and friends. Has any one experience with 10' radiant ceilings?
Incidently Engineer asked about temp parameters and the answer is we don't want water to freeze and we don't want "pilots" to have to wear parkas. A 50 degree target is ok.
I'll throw a thread on the radiant forum as well.
Thanks for your ideas,
Joe

Just my 2 cents as someone who isn't technically versed, but it seems like 10' ceilings would kill efficiency. Usually with ceriling height, you'd want to force it to go against nature and radiate down, which would best be accomplished by a fan, but horses = no forced air (plus, you wouldn't anything from the pilots to hit the fan). I'm going to say a manure burner would be the cheapest operation, definitely not safe or clean though.

Seneca, radiant heat by nature radiates in ALL directions naturally. It will radiate downward just as easily as it will radiate upwards. That's the whole point with insulating on the side you don't want it to radiate towards. Heat will transfer, but NEVER rise. Hot air or water, or steam, or whatever the medium, will rise in its elements.

Radiant ceilings will work wonderfully well. The reason floors are used more than ceilings are because of a few reasons.
First, the floor is easier to install it in.
Second, the physiology of us humans is usually (not always so) that our feet want warmth, and our heads want cool. A radiant floor, therefore, will be a little bit more comfy than a ceiling to us.
Third, it's easy to get a thermal mass on the floor instead of the ceiling.
I'm sure there are other reasons, too...

Radiant ceilings, though, will be comfortable when the temperatures don't get so hot like an electric radiant ceiling. Radiant heat will heat the objects it is radiating to (i.e. the floor, the throne, the people, the chairs, the ceiling, and somewhat the air). While with a radiant floor there is some natural convection currents caused, they are not very much. Not even close to the amount that radiant baseboard heaters have.

Anyway, I seem to be rambling again... The point is just that the radiant ceiling doesn't have to radiate against nature. It is its nature to radiate everywhere. Insulation is what's used to force it down, or sideways, or upwards...

My first question what be what do you consider an adequately heated space? Comfortable for humans? or Horses? Being that horses live outside in the wild, I would think they can withstand lower temperatures comfortably, when compared to humans. Granted horses have limited mobility in there stalls to warm themselves up by moving around, I'm sure there hides/fur keep them a lot warmer than a human with street clothes. So back to the original question, If this guy is only looking for enough heat to keep the horses from freezing, say anything over 50 degree F when the outside temp is Zero or colder would be warm enough, perhaps he does have enough sq footage after all. 
 

Alright. I thought that radiant flooring worked mostly on conduction to the air, followed by convection from the warmer air. I guess it does actually use thermal radiation just like it's name, radiate.

The point about cooling at the head is an incredibly good one. Humans build up massive heat at the the head (in fact, if we didn't have some of nature's most sophisticated cooling mechanisms in there, we'd overcook it) because of our brains being a very massive heat build. Horses won't have anything near that going on. There's a possibility warmth coming from above would actually be the most comfortable thing for them.

Notice Joe's work schedule is like TVLand re-run guides - first he's dealing with installing next to Mrs. Kravitz, now he's got an install for Mr. Ed.