My husband and I have just begun our DIY build and we are having some heating/cooling dilemmas. We are building with a concrete slab that will be insulated with rigid foam insulation underneath. We had initially planned for doing radiant floor heat. We will also have a woodstove. In terms of cooling the house, we normally would need AC maybe one week out of the summer but with the record heat temps we had this summer and with concerns about climate change we'd like to have an energy efficient cooling solution. So we are considering whether we do radiant floor heat + a woodstove + a minisplit? Is that over kill? Or do we lose the radiant floor heat and just do the minisplit + woodstove? Some considerations- -Winter average temps where we are low 20s, but there have definitely been below zero days as well. -We will have some element of passive solar heat with our concrete slab and a wall of windows and plenty of solar gain on our south wall. -I read elsewhere someone else had elected to do minisplit and no radiant floor heat with their concrete floors and their floors were comfortable in the winter due to the underfloor insulation. Has this been other people's experience? -Lastly, the radiant heat would need to electric powered, we are unable to do natural gas where we are. Wondering if that makes the radiant heat too cost prohibitive? Thanks in advance for any input.

If you want or need AC, then you want a mini split. The mini split can accomplish all your heating needs too.

If you want maximum heating comfort, HR floor heating is the way to go and it integrates well with a mini split too. In an energy efficient home, the floors will not feel very warm...but they will never feel cold either. So maybe something to consider. I would still recommend putting the PEX in the slab so it is future heating option. This is a very cheap provision if you are pouring an insulated slab anyhow. Just make sure it is properly designed and installed. You should look at the NextGen electric boiler if you decide to do electric HR. It is designed just for this purpose and will save you much money as you won't need an expensive HR panel. An air to water heat pump system would have much lower operating cost but for a much higher acquisition cost. So you would need to run the ROI numbers.

Wood stoves (including rocket stoves) don't work well in energy efficient homes. Same for fireplaces. You have to throttle them down so much to avoid severely over heating the living space which then results in high pollution and creosote. If you want to burn wood in an energy efficient home, look at masonry heaters which store and release the required building heat gain very slowly over a day or two with only one 1-2 hour 2000F degree clean/efficient wood firing. So you have the easiest and most efficient way to burn wood that is compatible with an energy efficient home. However, masonry heaters can be crazy expensive depending on the specific and how much of it you hire out to be constructed. Masonry heaters can be DIY constructed for lower cost.

We have info on all this stuff along with construction photos of our place on our website if interested. Our energy efficient and fire resistant single level home and detached garage/shop/guest quarters located in Southern Oregon is ICF, metal standing seam roof, passive solar cooled/heated, HR floor heating from NextGen boiler via stamped concrete slab HR emitters, and has a masonry heater. Free DIY design calculators for all this stuff can be found on our website too.

Thank you sailawayrb for all your input and advice, much appreciated! I will definitely be interested to check out your house. What do you do for cooling yours, the passive solar is enough to keep things cool in the summer? We are thinking we will likely go with exactly what you suggested which is to leave out the radiant heat for now, but to also go ahead and plumb for it. I would love to do a masonry heater but I'm not sure we can pull that off. In the meantime, though it may not be the most energy efficient solution, we'd still like to do a woodstove for the feel/ambiance of it. We haven't had one in years and I really miss it. We were thinking of installing a small, efficient one that is designed specifically for tiny houses. Thanks again for all the insight!

Glad I could help! Yes, our climate, our open floor plan in southern area of house, zero windows on west wall of house, the passive solar design, the interior thermal mass, and the well-insulated/sealed building envelope keeps the house cool in Summer and we don't need or have any AC. Our house never exceeds 68F (it is typically 65-68F in Summer) and we found this to be true even during the 25 continuous days of triple digit temps that we had this Summer (some 110F).

The passive solar design keeps the walls/windows from experiencing any solar heating. We open some windows before going to bed and our whole house attic fan comes on at 1 AM and turns off at 6 AM to cool the attic and to cool the house interior thermal mass which is typically 60-63F in Summer...we have thermal mass temp sensors as well room air temp sensors to monitor these temps. Our interior thermal mass consists of stamped concrete floor slabs, a 2' thick stone/brick masonry wall that runs the width of the house, the masonry heater and lots of granite kitchen counter tops and window sills. We close the windows shortly after waking up.

Please keep in mind that our approach only works when you have a low humidity, diurnal temp climate like we have. Even when our daytime Summer high temp is 110F, our nighttime Summer low temp is in the 60/50s. If you live in a climate that has high humidity and the nighttime temp never get significantly below 65F, you will likely need AC. Here are the direct links to our construction photos:

https://www.borstengineeringconstruction.com/Borst_Residence_Construction_Photos.pdf

https://www.borstengineeringconstruction.com/Borst_Shop_Construction_Photos.pdf

Gayle