Background: We recently bought 9 acres in the Ozarks of Missouri (hilly, rocky, forested area as opposed to the flat far fields in the rest of the state), sold our house in SE Alaska, and are now mortgage-free and using the equity we got from selling to set up our homestead. We bought a "reclaimed house," meaning a contractor was paid to remove a house from the property and is dismantling it, we bought the materials, he will deliver them, and then we will reassemble them in a different layout on our own property. It is going to be a conventional building overall when it comes to construction and materials. We have 6 kids and one needs wheelchair accessibility so it's going to be quite the large house (lots of bedrooms, big hallways, big open living spaces, etc). We are going to double walls for double the insulation, and are planning to build a low-grade geothermal air system for cooling (and for the greenhouse year-round, but probably has to be a separate system - this style:
). The house comes with two furnaces (I think electric?) and two a/c units (it was nearly 5,000 sq ft and set up almost like two homes - not something we are repeating). We will be running a hybrid electric system with solar and wind, but also a decent enoughbattery bank to support the majority of our needs should power fail. We will be using the old windows from the house to build a large attached greenhouse (roughly 40 x 28), with a low-grade geothermal system to cool in summer heat and keep it from freezing in winter. I'm currently planning an aquaponics system for it. We are also planning a DIY in-ground pool of the natural-pool variety (plant filtration) within the greenhouse space for our year-round use, as a heat sink, and for at-home physical therapy for my disabled son. We have big plans...LOL!
Question 1: How can we get a RMH to work for our home, basically. Details: My husband wants to use the HVAC ducting that will come with our reclaimed materials, and pipe the a/c of the geothermal into that, then use one of the a/c units we have as a back-up (We have one in our current manufactured home, 2 come with the house). We also have two furnaces that come with the house materials. Anyway, I'm wondering HOW to use a rocket mass heater to heat a multitude of bedrooms in a large house? Is it possible to somehow link the RMH into the air system? Is there another way of heating many bedrooms with one rocket stove? Would we need multiple stoves?
Question 2: I would LOVE to use a RMH in my greenhouse as a backup or auxiliary heat source during cold snaps. I see there is a design plan for a RMH for greenhouse use. We in theory won't need one to keep the greenhouse from freezing, but I would LOVE to be able to use it to keep the pool water swim-able year round. (Plus, the pool could act as a massive heat sink for the large space.) Is there a way to use the mass or vent piping of the RMH to heat the in-ground pool, then have the pool heat the greenhouse? This may be a tall order...
Question 3: Which DVD sets, books or plans would you suggest we purchase RMH applications? We haven't purchased the BWH or WBS DVD sets yet but would like to very soon. I figure we'd need BWH for sure but I've been wrong before. ;) Would the WBS set be suggested specifically for either application I have discussed or is BWH likely sufficient? Would either or both sets be sufficient to figure out a greenhouse heater or is it needful to order those plans as well? Can I really not buy both from the same website in one order?
If you've read this far, thanks for sticking with me and thank you for your time!
My first advice would be to make the new floor plan compact so that radiant heat can reach most of the rooms, especially ones you want to keep warmer. My inclination for using an RMH in a new big house might be to run the duct in mass below the floor, say under all the bedrooms. Another possibility would be to have a large bell-style RMH to heat the central spaces, with the forced air supply duct running through the bell cavity to be heated before heading to remote rooms. This would want some electronic controls to mix RMH-heated with non-heated air so the final supply was consistent. Depending on the layout, you are likely to need more than one RMH to give relatively even heating to a really big house on one level. A really well-insulated envelope will make concentrated radiant heating more effective.
A rocket mass heater is primarily a space heater. Theory is a highly efficient burn chamber that uses a small load of wood to generate incredibly high burn temps for a short duration of not much more than an hour or so. Intense heat from this burn is then stored in a large dense mass, where it slowly releases heat into the adjacent space. It may take a day or so to cool off, and radiates heat into the space during that time. It is a batch process used to heat a limited surrounding space.
Heating and cooling a large structure with wood gets to be problematic in a hurry. For you to utilize such a process will mean you will need to graft the highly efficient burn chamber......the one that generates all that intense heat......into a distribution system that moves the heat throughout the house.
One system normally used to distribute heat from a central heat source is forced air........warm air is ducted throughout a house. But even that has size limitations. A big house will have multiple furnaces if you stick with forced air. When only one heating system is used in a large area, an old way of doing it was to use steam or hot water, which can utilize a single heater, and pump the hot fluid throughout the structure. The heat is released into the rooms using radiators, or fin tube or some such thing. The release of heat into the room is similar to a RHM in that is utilizes both radiant heat and heats the air so there is some convection as well. Hot water and steam heat is comfortable. Or, if a one story home you can do something similar by using cement floors as the mass and let your floors become your radiators. But if you did this, using a Rocket core would be a dicey thing to devise. You would need a lot of experience with water, steam and wood heat and burning wood to pull it off.
The other option for heating multiple rooms is something like that used in motel rooms. Each room has it's own heating and cooling. But those run on electricity......not wood.