Hi Everyone, I have begun a new home project and decided that I want Hydronic radiant heat in all floors. This would be a 865 sqft basement, 860 sqft Main floor and 347 sqft Upper floor. I'm located in Montana and the only contractor I could locate here specified in his proposal a WF NSW060 water-to-water system with 4 vertical bores for the closed loop. I wasn't told the depth of each bore. Although I sent him my build plans and specified direction the house faces and type of insulation which would be used throughout, I was not exposed to his Manual J calculations. I told him at the time that I would like the unit to also provide cooling but that is one of the problems. He says that the most cost effective solution to cooling would be to install a ductless Mitsubishi A/C system with one outdoor unit and several indoor units. The contractor didn't say he couldn't do cooling with the Geo system, only that it would require a lot of extra work and cost. As it is, the system with heating only is priced at above $40k but includes all well/ground loop work and hot water assist. Does this make sense? It is more cost effective to just have a separate Air A/C system?? Thanks for any advice.
One can cool with radiant floors removing the sensible heat. The latent load will require a system with the ability to remove moisture. I like teaming my water to water systems with Unico equipment. Mark
Not really. The NSW can be ordered reversible, and then you can provide chilled water to an air handler. Plus, once you have a heatpump making hot water, why don't you have all your domestic hot water made by that heatpump, not just hot water assist, which I assume is a desuperheater. Plus you get the tax credits for the A/C part of the geosystem, but not for an ductless mini split. here is an example. http://welserver.com/WEL0664/
It depends on how you wand to cool with your WTW. Your choices for geo cooling would be a complete duct system and hydronic air handler or multiple hydronic consoles which are less attractive than the split air source heads. James Schneck is a very progressive geo builder in Montana. jamesatenergy-dynamicsdotcom
Hi Kenny, Where in Montana are you located? I am in Bozeman and I am the territory manager for the state for Energy Dynamics which is the distributer of Enertech mfg. products. (Hydron Module & GeoComfort). I would be happy to see if I have a dealer in your area that can provide you a system quote. A water to water system can be easily applied in a cooling application. It can have radiant cooling aspects and/or can have forced air distribution elements. The radiant cooling will need to be controlled so that the supply water temp stays above the dew point. The fan coil(s) will receive chilled water below the dew point. I would be interested in learning more details of your project and seeing if there are some approaches that may be being overlooked.
Thanks for your responses people. As I said, I know cooling could be done with Geo but am concerned with the cost vs a simple ductless A/C solution. The ductless system was quoted at about $6.5k so how much would a ballpark figure for chilled water system run me? James, I'll contact you privately if that's okay. Kenny
Doc, I told the contractor that I want DHW - I didn't say an assist. He said the system doesn't provide hot water and can only assist. He says a separate water boiler is required. Yes, his quote include a desuperheater.
Hey Mark, I looked at the Unico systems you refer to and must say I really like it. All I need to do is find someone out here in Montana who can pair it up with my Geo system, and get an estimate on costs. Kenny
Kenny as I'm sure you are noticing there are many ways to accomplish what you want. 6.5 K for the multi head unit is likely not inclusive of all facets of the installation (i.e. electrical) and Doc makes a good point about the tax credit.
You are usually looking at 2-3K for the air handler, plus the ductwork and a few added valves and controls. You probably looking at the same 6.5K all together, but you have now an all house central A/C and can apply the tax credits. I don't know Montana prices. In regards to full hot water (not just assist), you need (must!) get another contractor if he does not know on how to generate full time hot water with a heatpump designed to make hot water. This is just silly!
Thanks Doc, just curious - How does the system generate hot water in the summer when it is removing heat from the house?
System prioritize on hot water, reversing valve switches unit from cooling into heating mode, heats up the DHW tank while buffer tank acts as a cooling reservoir, after 10-20 min DHW tank is heated up again, unit switches back to cooling
