EcoRenovator - View Single Post - standby losses from the hotwater tank add up

strider3700 · 10-22-12, 01:59 PM

I was playing with my IR thermometer this morning, and since the hot water hadn't been used in awhile I decided to check the line temps in my heat trap. Checking the TED the heater hasn't run in 4 hours and the last measurable hotwater usage was 14 hours ago so it's likely that line temps have returned to there standard no hotwater usage state.

Here you can see the trap on the wall, it's just a down over then up.
https://lh4.googleusercontent.com/-T...3/IMG_6038.JPG

The top of the trap right before the down is currently reading 30.3 C behind the insulation. The bottom of the trap is reading 22.6 C

The foam insulation read's 23.4C at the top and 22.1C at the bottom.

The tank insulation reads 21.6 at the top of the tank and 20.9 C at the bottom of the tank. the wall behind the tank reads 21.5C at the top of tank height and 19.8 at the floor height.

So the loop is really helping reduce the amount of pipe that is heating up due to rising hotwater from the tank. The insulation on the pipes is also making a big difference compared to bare copper that I originally had. All of the hot parts are still reading higher then ambient temperature but only by a little bit. If I find some insulation that fits I may wrap the 15" or so of pipe going into the top of the tank a bit more but beyond that I'm pretty happy with this.
The tank could also use more insulation. The TED says it kicked on for 4 minutes at 10:14, 12:36, 3:55, and 7:29 The last hotwater usage was at roughly 8:00. so that's 16 minutes of standby overnight or 1.2 kwh costing me 8 or 12.5 cents depending on which tier my electric bill is in. assuming things were to stay like it was last night and we go worst case highest cost tier that's $45/year or 438 kwh in standby losses. That's a crap load but nowhere near enough to justify the cost an on demand would have cost me. That amount could easily justify a 220V timer however. I'll see what I can find

I'm currently thinking in the long run the tank and the solar hotwater storage tank will have a closet built around them and that will be insulated as well. I'm not convinced that wrapping another insulation blanket around the tank will make much of a difference but if I see something that will work I'll buy it and give it a try. I wish they made 4" foil backed fiberglass or rock wool and it was available around here.

10-22-12, 01:59 PM	#24
strider3700 Master EcoRenovator Join Date: Dec 2008 Location: Vancouver Island BC Posts: 745 Thanks: 23 Thanked 37 Times in 30 Posts	I was playing with my IR thermometer this morning, and since the hot water hadn't been used in awhile I decided to check the line temps in my heat trap. Checking the TED the heater hasn't run in 4 hours and the last measurable hotwater usage was 14 hours ago so it's likely that line temps have returned to there standard no hotwater usage state. Here you can see the trap on the wall, it's just a down over then up. https://lh4.googleusercontent.com/-T...3/IMG_6038.JPG The top of the trap right before the down is currently reading 30.3 C behind the insulation. The bottom of the trap is reading 22.6 C The foam insulation read's 23.4C at the top and 22.1C at the bottom. The tank insulation reads 21.6 at the top of the tank and 20.9 C at the bottom of the tank. the wall behind the tank reads 21.5C at the top of tank height and 19.8 at the floor height. So the loop is really helping reduce the amount of pipe that is heating up due to rising hotwater from the tank. The insulation on the pipes is also making a big difference compared to bare copper that I originally had. All of the hot parts are still reading higher then ambient temperature but only by a little bit. If I find some insulation that fits I may wrap the 15" or so of pipe going into the top of the tank a bit more but beyond that I'm pretty happy with this. The tank could also use more insulation. The TED says it kicked on for 4 minutes at 10:14, 12:36, 3:55, and 7:29 The last hotwater usage was at roughly 8:00. so that's 16 minutes of standby overnight or 1.2 kwh costing me 8 or 12.5 cents depending on which tier my electric bill is in. assuming things were to stay like it was last night and we go worst case highest cost tier that's $45/year or 438 kwh in standby losses. That's a crap load but nowhere near enough to justify the cost an on demand would have cost me. That amount could easily justify a 220V timer however. I'll see what I can find I'm currently thinking in the long run the tank and the solar hotwater storage tank will have a closet built around them and that will be insulated as well. I'm not convinced that wrapping another insulation blanket around the tank will make much of a difference but if I see something that will work I'll buy it and give it a try. I wish they made 4" foil backed fiberglass or rock wool and it was available around here. Last edited by strider3700; 10-22-12 at 02:03 PM..