cafoose 3,456 #1 Posted July 24 I'm in northeastern Tennessee in the mountains where sometimes in the winter months it gets below freezing for several days. My place has a heat pump which works very well above 35 degrees or so. When it gets below that, the furnace blows cold air. I'd like to do something soon because my electric bill goes way up in the coldest months and I want to get it done before I don't have time before the cold. I have access to free firewood but nowhere inside to put a wood stove. I was thinking of an outside wood stove piped to my existing duct work. I found the most popular are the outdoor wood boilers but they are more expensive and difficult to build. Another less expensive and easier way is to build is an outdoor(water less as it's commonly called) forced air furnace. The boiler is supposed to be much more efficient. I thought of solar panels but the days aren't long enough to effectively charge a normal sized battery bank. Enough batteries to handle the load at night would be way too costly. No gas pipelines in my area. Propane tanks and filling them is very expensive. Any thoughts, suggestions? @Pullstart @ebinmaine @Ed Kennell or anyone else? Share this post Link to post Share on other sites
ebinmaine 72,987 #2 Posted July 24 Given your circumstances it seems like the outdoor forced air furnace may be a decent option. We've looked at heat pumps here and of course.. didn't use one. The new workshop space has an AC/Heat combination unit, a heat only unit, and a large wood stove. Up here electricity is on the pricey side but we just consider it a way of life. Ya gotta be comfortable - or at least above to use a space. 2 1 Share this post Link to post Share on other sites
Handy Don 14,129 #3 Posted July 24 The newer technology in heat pumps can operate efficiently to supply heat down well below freezing (without using electric resistance supplemental heat). They are also more efficient overall. Depending on the age of your unit, the total cost of replacing it may be less (in materials plus labor), than buying and “splicing in” a new external heat supply. Keep the same simple thermostat control, add no new fuel requirements, and possibly gain lower operating costs during the spring/summer/fall seasons. 3 1 Share this post Link to post Share on other sites
oldlineman 1,541 #4 Posted July 25 My son had a mini split system installed last summer and it heated his house last winter on days that were down to zero, kept the house at 70 to 75 with no problem a large one story brick three bedroom house. They have come a long way with these units. It will heat in winter and cool in the summer,very efficient units.He actually saved on his electric bill from a natural gas hot air furnace and some electric baseboard units. Bob 2 1 Share this post Link to post Share on other sites
ebinmaine 72,987 #5 Posted July 25 Up here we seem to see a usable lower range done to 18⁰ to 25⁰ depending on the unit. Below that the electric heat portion kicks in. 1 Share this post Link to post Share on other sites
lynnmor 7,858 #6 Posted July 25 You might want to call propane suppliers that will fill your bulk tank. Small portable bottles can be very expensive. Propane has been economical in recent years and you should investigate it thoroughly before tossing out that option. I have an indoor wood/coal furnace tied to the ductwork, an outdoor unit would be a pain to feed in brutal weather. My heat pump runs when the wood heat is down and an oil furnace takes over below 35 degrees. I have another house that I recently installed a very high efficiency heat pump with resistance heat for those few time that the temperature is below 11 degrees. Wood heat is available for special occasions and emergency heat. 1 1 Share this post Link to post Share on other sites
Pullstart 67,042 #7 Posted July 25 I haven’t worked on this, it’s challenging to do R&D when you don’t want the heat. I have plenty of ideas to improve upon. 1 1 Share this post Link to post Share on other sites
Skwerl58 766 #8 Posted July 25 We live in SWVA and use wood to supplement the heat pump. Our heater is built in the duct system and water system and has been going for 40 years. We had to replace our heat pump last year and it is superior to our 24 year old unit. I have wood cut for 3 seasons and may start cutting back because of the savings the new HVAC system has created for us. If building new I would definitely look at a new outdoor wood system but with the new HVAC units and efficient homes cost savings is not as great. Like stated propane is a good option if you have a good company or gas line close by. 1 1 Share this post Link to post Share on other sites
WHX?? 51,909 #9 Posted July 25 4 hours ago, cafoose said: sometimes in the winter months it gets below freezing for several days Say what??? Try this for a week straight... Heat pumps & mini splits are great but are very complicated. Loaded with high tech circuit boards and expensive when they break. You won't fix it yourself and finding a decent service tech is ??? 1 1 Share this post Link to post Share on other sites
ebinmaine 72,987 #10 Posted July 25 7 hours ago, WHX?? said: decent service EXCELLENT POINT !! There's a serious consideration. It doesn't matter if the system you choose is the finest in the universe if it isn't maintainable. Share this post Link to post Share on other sites
oldlineman 1,541 #11 Posted July 25 (edited) The unit is a mini split, his can handle 5 air handlers ,advertise to produce heat down to - 20 deg. granted not a lot of heat, most likely at that temp.It has no electric backup for colder weather, just able to recover less heat from the outside temps. Was installed buy a very good German Baptist gentleman with a great knowledge and work ethic, does beautiful work and very dependable. Those are people we look for where I live, great workers to do all kind of work very fair priced also. Bob Edited July 25 by oldlineman 1 Share this post Link to post Share on other sites
