Boilers - Steam and Hot Water Systems - hydronic cooling/ water chiller

I was doing a little bit of looking online, and come across a variety of different chiller systems, that can be integrated with a hydronic heat system to also cool a home as well. How hard are these to integrate? Will baseboard registers work with this since I seen registers suspended from the ceiling? Are there any good resources out there that would provide me with more information about this???

Won't work with baseboards... you would have water dripping off the fins all over the floors...

Chillers are used with 'air handlers' that have fan coils in them, air is blown across the chilled coil... much like an A/C air handler, but instead of using a refrigerant, they use chilled water. And there will be condensate to be disposed of.

so, the ceiling mount type registers would work for the condensation? The ceiling mount registers that I have seen have some type of a drip pan for condensation? Do you know of any good vendors for pricing out a system like this?

I really don't know enough about the systems to advise... but in addition to the air handlers, you would also need a 'chiller' device to cool the water. I believe you are much better off with a regular air conditioning unit.

There is radiant panel cooling that is placed in the ceiling.
The system is basically designed not to condense.

Really depends on where you home is located, but generally you need dehumidifaction more cooling.

Honestly the best cooling for hydronic homes (as long as they are not too big ) has to be a ductless split unit in my opinion.
You can get multiple heads running on one outdoor unit now, and they modulate the compressor now ( some of them) so they are super effiecient.

where could I find more info on these ductless split units? I live in South Dakota, so the summer is mild, but can be humid at times. The total square footage of my house is approx 3000sq ft, including the basement, which is not finished at this time, but will probably get finished at some later point and time, so the unit would have to handle at least that much.

I would look into the high velocity systems if you don't have duct work already in your house. The ducts they use will fit into a 2x4 stud bay. It's not as invasive as a full size duct work installation would be. And it will be easier to find places to run the new ducts.

well, the reason I was looking at a chiller system, is because I have a 1 1/2 story house, which the upper level and main level are fully finished, and the basement is the only thing unfinished. I was hoping to utilize the existing boiler piping for a heating and cooling solution to minimize tearing my house apart for a forced air solution.

although the current system might provide some cooling, it is most likely not enough due to the lack of convective air currents with the baseboards at floor level. When you heat, the air naturally rises and draws more air across the radiator. If you used this with AC, there would be nowhere for the air to move to after it cooled the lower couple inches of the room.


you also have the condensate to deal with as well.


as to integrating such a system; it is done all the time in commercial buildings but they use a fan coil unit to move the air.

well, the reason I was looking at a chiller system, is because I have a 1 1/2 story house, which the upper level and main level are fully finished, and the basement is the only thing unfinished. I was hoping to utilize the existing boiler piping for a heating and cooling solution to minimize tearing my house apart for a forced air solution.

Mitsubishi is best known for their Ductless, Hitachi, LG... lots of Japanese makes.
The beauty of the ductless splits is the refriderant and power line are all outside.

You generally do not need to condition a basement for cooling.

ah ok, I do believe that a friend of mine did tell me about the mitsubishi system. This is a "central air" type system where the unit sets outside, then piping is plumbed outside of the house to each floor, correct? How efficient are these units compared to a conventional window air unit? Currently I have two window air units, one on each floor, and during the summer months, these units run almost constantly.... which makes for a scary electric bill!:eek:

As for the basebaords in the hosue, I have concluded that these would have to be changed out. I have seen "valance type" units that are similiar to a baseboard, but mount up near the ceiling. Supposedly these units will work for both heating and cooling. They are also said to be able to deal with the condensation as well. I would not be against changing to this type of unit. I would simply have to extend the current pipes up the wall, then in theory, they would work for heat or cool. But which is worth the while? The articles I have read about chillers indicate that they use roughly half the power of a forced air unit.

The articles I have read about chillers indicate that they use roughly half the power of a forced air unit.
do you have any of those articles handy? I would like to read them if so.

trying not to get too technical; a chiller is an AC unit that instead of having a coil in the air handler, transfers the cold (I know, technically it removes the heat from the water) to the fluid. That fluid is then pumped through the system and the imparts the cold (yes, I still know, absorbs heat from) to the air.

I do not see how it could save that much power.

here is the link of the graph that compares forced air cooling to hydronic cooling.

Hydronic Radiant Cooling Systems (http://eetdnews.lbl.gov/cbs_nl/nl4/RadiantCooling.html)

Not sure I understand that graph but what I do see is they are simply chopping off the fan (air circulation) costs from the cooling costs. This is a somewhat erroneous claim.

Especially in a radiant system (no forced air used in the actual system), you still require circulation fans to prevent stratification of air in any given room plus you still need to ventilate the building with fresh air. While each of those can use smaller fans to accomplish the purpose, they are a very real cost which reduces the savings graphed.

then, with a radiant system, as opposed to a fan forced air system, even if using a hydronic system, the time it takes to heat or cool an area is greatly increased.

So, that means you don't use the t-stat to set up the temp until an hour before you come home and still expect a cool house (or vice versa; a warm house in the winter). You do not have the ability to achieve savings from overnight set ups or set backs due to the lag inherent in radiant systems either. You simply must intend on maintaining a consistent temp due to the slow reaction times.

there are pluses and minuses of each system and both work well if the system is designed well and the weaknesses of any system are understand and accepted.

I currently have a boiler for heat, and so far, it seems to be doing a very good job. As you said, it does take them some time to recover and heat or cool a room. But once the target temperature is achieved, the unit in my home will cycle on average 1-2 times per day. It does have some weak points though, which I am looking into, and do understand. But, so far, with operating this unit, I have not seen any substantial jumps in electric, or natural gas bills, so I will have to give it some more time to see what happens. Finally, I would like to implement a chiller system, for the simple fact that boiler piping already exists, and to change out the baseboards to something else would be pretty easy, compared to having to tear the house apart to install duct work for a forced air system.

Not sure I understand that graph but what I do see is they are simply chopping off the fan (air circulation) costs from the cooling costs. This is a somewhat erroneous claim.

In that particular graph, they are comparing the water circulation pump power consumption to that of a blower motor in a forced air system. Although, as you said, it does leave a few things out. Here is another article that I read about hydronic cooling, here this article illustrates what type of medium would have to be set in place of baseboards that would work for both heating and cooling. As trooper said before, with cooling, you would be dealing with condensation, this particular unit has a "drip tray" to collect the condensation from cooling. In order to install this type of valance unit would be very easy. Simply remove the baseboards, and extend the pipes up the wall, yes, it does require some sheetrock to be cut, but in very small amounts.

Here is the link:

ESB: Hydronic Cooling (http://www.oikos.com/esb/53/hydroniccool.html)

I understand exactly what you are considering and to me, it makes a great deal of sense. I was merely drawing your attention to the fact the link you posted is comparing radiant systems to forced air systems. It isn't a fair comparison unless you consider the other items I mentioned; ventilation and destratification.

If you overcome those (the ceiling mounted unit would remedy the stratification (for cooling only, it would cause stratification if used for heating). A ceiling mounted unit for cooling and a floor mounted unit for heating would take care of all seasons.

You always need to consider fresh air ventilation in a building, especially as they become more and more airtight. Mold is only one of the problems caused by inadequate ventilation.

all in all, I like your idea and actually would like to hear the outcome once you figure this beast out.

well, according to the last link in which I posted, this article "claims" that the valance, ceiling mounted "radiator type" unit supposedly works for both heating and cooling. I still need more information and education before I begin penciling out a system, and figuring out the cost of the sytem as well.

well, I do not see any reason you would have less trouble with stratification if you heat the upper area than you would if you cooled near the floor but I am not an engineer.

Maybe they know something about fluid dynamics and the effects of thermal incongruities of multiple strata in a closed environment with no active means of providing motion I am missing.

As I said before, I wish I could find a good resource of information on this type of system. From the basic info in which I have read, I am confident that it would work rather well.

well, it is used in commercial systems all over the place if that makes you feel any better. Most use a fan coil but there are some of the simple convection systems as well.