Hi All,
So for anyone who isn't familiar with the concept of a tempering tank, there is plenty of information online, but basically one uses an already present source of heat (such as the sun or a wood stove) to warm water in a small tank. Then, when you draw water from your hot water heater (for a shower etc), it is replaced by already warmed water - thereby reducing the amount of electricity needed to heat water again. I had only recently heard of it and was very interested in the concept, and so have started to try it out.
This summer I took my first delve into the realm of the solar hot water tank and failed miserably . I constructed a large (40 gallon) batch tank to use as a tempering tank. Not sure if my positioning was off, or the tank was too large, or if the weather was just too crummy (we basically had a three week summer this year), but I did not get the kind of results I was hoping for. Oh well, moving on, right?
I've decided that for my next project I will take the solar water tank idea and instead construct a tempering tank to place behind my wood stove for the winter months. This is what I am going to do.
1) I have cut a large portion out of the original 40 gallon hot water tank (my solar heater), and welded the top and bottom together. The tank now holds around 10 gallons. Using a hot water tank in this manner allows me to retain use of the various fittings (cold water supply, relief valve, drain valve, and sacrificial anode).
Unfortuantely, I'm just learning to weld, so my welds were NOT water tight. After a lot of head scratching and cursing, I finally managed to stop the holes using a tube of silicon that is rated for >200 degrees fahrenheit (I purchased it in the wood stove section of a local hardware store)
2)Next I will place the tempering tank on a small rack directly behind the wood stove. I will not have them touching as I have a few concerns regarding this:
a) contact may cause water to get too hot, either causing the releif valve to set off frequently, or scalding someone in the shower,
b) the silicone sealant I had to use is rated for 200 degrees, which I think would be exceeded if contact were made. I'm hoping that a small distance will decrease this.
3) I plan to use copper piping to run from the tempering tank to my hot water tank. Although at some point I would like it to join into PEX piping (cheaper). However this will be something I'll evaluate as I go.
Please feel free to add any suggestions/questions/comments/experiences. I have never done this before, so I'd love to get input.
I'd like you to remember however that I am not setting this up as a primary water heater. We only burn wood as a supplementary heat source (i.e. evenings and weekends) so anything geared towards making that sort of system would probably be a great idea for another thread.
Thanks in advance
So for anyone who isn't familiar with the concept of a tempering tank, there is plenty of information online, but basically one uses an already present source of heat (such as the sun or a wood stove) to warm water in a small tank. Then, when you draw water from your hot water heater (for a shower etc), it is replaced by already warmed water - thereby reducing the amount of electricity needed to heat water again. I had only recently heard of it and was very interested in the concept, and so have started to try it out.
This summer I took my first delve into the realm of the solar hot water tank and failed miserably . I constructed a large (40 gallon) batch tank to use as a tempering tank. Not sure if my positioning was off, or the tank was too large, or if the weather was just too crummy (we basically had a three week summer this year), but I did not get the kind of results I was hoping for. Oh well, moving on, right?
I've decided that for my next project I will take the solar water tank idea and instead construct a tempering tank to place behind my wood stove for the winter months. This is what I am going to do.
1) I have cut a large portion out of the original 40 gallon hot water tank (my solar heater), and welded the top and bottom together. The tank now holds around 10 gallons. Using a hot water tank in this manner allows me to retain use of the various fittings (cold water supply, relief valve, drain valve, and sacrificial anode).
Unfortuantely, I'm just learning to weld, so my welds were NOT water tight. After a lot of head scratching and cursing, I finally managed to stop the holes using a tube of silicon that is rated for >200 degrees fahrenheit (I purchased it in the wood stove section of a local hardware store)
2)Next I will place the tempering tank on a small rack directly behind the wood stove. I will not have them touching as I have a few concerns regarding this:
a) contact may cause water to get too hot, either causing the releif valve to set off frequently, or scalding someone in the shower,
b) the silicone sealant I had to use is rated for 200 degrees, which I think would be exceeded if contact were made. I'm hoping that a small distance will decrease this.
3) I plan to use copper piping to run from the tempering tank to my hot water tank. Although at some point I would like it to join into PEX piping (cheaper). However this will be something I'll evaluate as I go.
Please feel free to add any suggestions/questions/comments/experiences. I have never done this before, so I'd love to get input.
I'd like you to remember however that I am not setting this up as a primary water heater. We only burn wood as a supplementary heat source (i.e. evenings and weekends) so anything geared towards making that sort of system would probably be a great idea for another thread.
Thanks in advance