I am looking for advice from similar-minded people, you guys on this forum, on an effective and appropriate backup system for domestic hot water production.
Some background information first. I built a timber-framed home, completed and moved in in December 2007. It has around 4300 square feet of finished space, including a basement with radiant in-slab tubing, and two floors above with staple-up tubing. I have three bathrooms with showers, plus two half baths and the usual complement of appliances that use hot water. Currently I use a Central Boiler CL5648 classic outdoor wood furnace that was bought new when I started the house. It is a Dual-Fuel model with a Wayne gas burner installed. This is the only heating system I have. There are no other wood stoves, fireplaces, backup systems, anything at all that would allow me to produce sufficient heat or hot water if the OWB failed for any reason. For that reason, the CB unit has been running continuously since approximately October of 2006. I've had it offline for short periods (4-12 hours) for maintenance or repairs occasionally.
I am now in the process of building a detached 900 sf garage, which will also have radiant in-slab tubing heated by the same OWB. The garage only needs to remain above 62 degrees, and will have no separate hot water demands. I am planning (but not 100% definite) to put a large solar array on the roof of the garage which will be a grid-tied PV system. I also have an above-ground pool that I am working on a heat exchanger system for boosting the pool water temperature just a little bit with the OWB.
What I am looking for, is advice on some kind of backup or secondary heating system that will cover domestic hot water in July and August, and any other time a backup is needed (i.e. winter vacations) Not more than three months out of the year. I want to be able to take my wood boiler offline for greater periods of time than just one day, for extended maintenance, cleaning, or simply to take a break. It is somewhat annoying to feed a fire when it's 90 degrees outside.
I am looking for something very small, that can be installed on a wall in the basement, and can tie into my existing system. I'd like to be able to flip a switch and have the unit start producing hot water that would then supply my existing 40-gallon passive hot water tank. Either gas or electric would work, and I am not leaning specifically one way or the other. Electric I think would be "easier" but I worry a bit about the cost - although a solar array would certainly offset the electrical costs.
What success have you guys had with the available technology? I will answer any questions about the sizing or layout - I'm not really looking for professional advice but more of an educated opinion on what works for you and why. Looking for pros and cons, what you're happy with, brands and models if you want, etc. Thanks.
EDIT: I probably should add that I am really unhappy with the efficiency of the gas portion of my OWB, and it doesn't really allow me to totally shut the system down. If I develop a leak, for example, and have to re-weld my firebox - I have no heat or hot water at all.
Some background information first. I built a timber-framed home, completed and moved in in December 2007. It has around 4300 square feet of finished space, including a basement with radiant in-slab tubing, and two floors above with staple-up tubing. I have three bathrooms with showers, plus two half baths and the usual complement of appliances that use hot water. Currently I use a Central Boiler CL5648 classic outdoor wood furnace that was bought new when I started the house. It is a Dual-Fuel model with a Wayne gas burner installed. This is the only heating system I have. There are no other wood stoves, fireplaces, backup systems, anything at all that would allow me to produce sufficient heat or hot water if the OWB failed for any reason. For that reason, the CB unit has been running continuously since approximately October of 2006. I've had it offline for short periods (4-12 hours) for maintenance or repairs occasionally.
I am now in the process of building a detached 900 sf garage, which will also have radiant in-slab tubing heated by the same OWB. The garage only needs to remain above 62 degrees, and will have no separate hot water demands. I am planning (but not 100% definite) to put a large solar array on the roof of the garage which will be a grid-tied PV system. I also have an above-ground pool that I am working on a heat exchanger system for boosting the pool water temperature just a little bit with the OWB.
What I am looking for, is advice on some kind of backup or secondary heating system that will cover domestic hot water in July and August, and any other time a backup is needed (i.e. winter vacations) Not more than three months out of the year. I want to be able to take my wood boiler offline for greater periods of time than just one day, for extended maintenance, cleaning, or simply to take a break. It is somewhat annoying to feed a fire when it's 90 degrees outside.
I am looking for something very small, that can be installed on a wall in the basement, and can tie into my existing system. I'd like to be able to flip a switch and have the unit start producing hot water that would then supply my existing 40-gallon passive hot water tank. Either gas or electric would work, and I am not leaning specifically one way or the other. Electric I think would be "easier" but I worry a bit about the cost - although a solar array would certainly offset the electrical costs.
What success have you guys had with the available technology? I will answer any questions about the sizing or layout - I'm not really looking for professional advice but more of an educated opinion on what works for you and why. Looking for pros and cons, what you're happy with, brands and models if you want, etc. Thanks.
EDIT: I probably should add that I am really unhappy with the efficiency of the gas portion of my OWB, and it doesn't really allow me to totally shut the system down. If I develop a leak, for example, and have to re-weld my firebox - I have no heat or hot water at all.
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