Help! We are at a decision point here and do not know which way to jump.
We are reto-fitting and older home in the (SW coast of Oregon) 3 story 4000'sq ft' with an existing wood stove (works great).
The underground portion of the geothermal system is in.
Problem - 5T geothermal heat pump with ducting or a geothermal water to water heat exchanger with PEX and registers? The house has open beam throughout and 2-3" thick floors... radiant flooring does not seem to be an option...
I was considering a combination:of ducting the basement and main floor , with radiant registers on the top floor.
Should we buy the water to water and go 100% registers; the heat pump and go ducted?
Which is more efficient? More comfortable?
Thank you for any ideas and or opinions... Cherie

By "registers", do you really mean "panel radiators"?



Panel radiators will be more comfortable than forced air, but may take temps higher than the geo can efficiently produce unless you have a LOT of panel area.

A lower-temp option more appropriate to geo output temps would be to go with radiant ceilings, which uses the same tubing & heat spreaders etc as floors but mounted behind the ceiling gypsum rather than the under the floor:



Be sure to insulate above the radiant (no insulation shown here) or you'll end up heating the room/roof above as well as the intended room. 

This approach can be applied to walls as well, if you need more surface area to get the water temps down.

S-OR coastal design day heat loads are comparatively low- I'm pretty sure a radiant ceiling approach would work well with geo in your location, and would be more comfortable than low-temp geo air.

I would be glad to make a proposal on your job!  [email protected]

http://www.hendricksonhvac.com/site/

No thank you, we already have a contractor lined up for the heat exchanger equipment. They may run the PEX lines also; but we have fmily members experienced at installing multiple types of systems. That is where my dilema came in... too many cooks...

Thank you for the response tho., Cherie

Thank you for your reply! I have never used one of these forums B4.

I probably do mean panel radiators, seems everyone (including internet searchs) ID's the products differently.

I had origanlly assumed (not a good word) that my brothers were wanting radiant floors but then I was informed that they had been reinforced when the house was restored.

Turns out our neighbors had the panel radiators and dad wanted those so he started to set the lowest floor of the house up for them before he died ('91). The house never got beyond wood heat. Mom is in her 80's now; I am insisting we install something that will keep her warm without high fuel bills.
I like the idea of the radiant ceiling - one question. Heat rises, does this really heat down to the floor? Or is the upper part of the room warm and the floors a lot cooler?
Carrier carries a water to water exchanger that puts out 145 degrees hot water; is that enough for the panel radiators?

Thanks agin for the advice, Cherie

Hot air rises. Heat goes from hotter region to cooler region, regardless of direction. In ceiling radiant the heat radiates from the ceiling to everything below it. The floor, furniture, people, etc., all absorb the radiant heat and feel warm. The air in the room is warmed by all the floors, walls, furniture, etc., warming the air that contacts them. The only downside I've ever really heard about ceiling radiant is a person's legs may feel cool when they are underneath a table or desk. That's because the table blocks the radiation from the ceiling to the legs. If the system is not designed correctly, and the ceiling is allowed to be too hot, you can have a situation of "hot heads."

Radiant ceiling is a great way to go, but it must be designed properly. I was going to do that in the house I recently finished but opted for a lower cost, high efficiency, air-to-air heat pump system.

145F is hot enough to work with panel radiators but it's a lot LESS efficient for the heat pump to make 145F water than is is to make 100-110F water, which is where you'd likely be with radiant (TBD by the designer.)

In a 68F room environment with an 80F ceiling or floor a bit more than half of the heat transfer is from direct radiation (ever stuck your hand UNDER a heat lamp? Did it feel different from your hand being OVER a heat lamp?)  It'll feel quite comfortable, even cozy at 68F since your being heated directly.  Yes, the warmer air will stratify somewhat toward the top of the room (a very slight effect except in very tall rooms) but everything in the room, including the occupants is being heated by the radiation, not contact with the air.  The stratification is much lower than you might think.  If you went with geo-air you'd have to keep the place 70-ish or more to get the same comfort level, and if the outlet registers are placed such that you get the direct breeze of that fairly tepid air, you'll get a wind-chill effect.