Review: Bosch 26 Eco+ vs Bosch highflow 26e
Recently, my friend was asking me about which model of hot water system he should purchase. He’s renovating a house and tossing between the Bosch 26 eco+ vs Bosch highflow 26e. This initial cost difference is $700.
Just in case not everyone is aware of what I’m referring to, Bosch manufacture continuous flow hot water systems. Therefore, you don’t need a water tank to store hot water.
Here are the quick specs about both units.
Bosch 26 eco+
- Water flow: 26 L/min (25°C rise)
- Star Rating: 6.9
- Mj/Hr: 178
- Gas Type: NG/LPG
- Carton Weight: 32 kg
- Heat Exchange Warranty: 10 years
Bosch highflow 26e
- Water flow: 26 L/min (25°C rise)
- Star Rating: 5.53
- Mj/Hr: 200
- Gas Type: NG/LPG
- Carton Weight: 22kg
- Heat Exchange Warranty: 10 years
As you can see, we are comparing apple to apple. They both have the ability to heat water up to 26 L/min at 25°C. Using the same gas, the 26 eco+ unit is 10kg because it has the ‘extra’ in it to make it run more effectively. So, how can we work out is it worth the extra initial cost in exchange for the long term saving?
I gave my friend a quick answer as well as a long one. The quick answer is if the purpose of the renovation is for resell, then it is not worth the additional cost. However, if it is for a long term, there may be a case for it.
Case study – Resell
When you renovate a house, the goal is to profit as much as you can, therefore, you save the $ without compromising the outcome. This is one of example that a more expensive and environmentally friendly hot water system may sound good but it does not bring in the additional dough. You may say I’m being cheap but the truth is, you don’t know what the next owner wants? He/she may want a solar powered hot water system because the gas unit is not 100% green.
Case study – Long term use
If you’re planning on getting the unit because you’re going to use it for for the long term, you may need to crunch the numbers. Here is my analysis, you need to know, numbers are there for playing, so you may need to do your own numbers.
26e use 200 Mj/Hr and 26eco+ use 178 Mj//Hr, therefore, 22 Mj/Hr difference and this is the only difference between the two units. The newer unit saves 22 Mj/Hr but how does that translate into $$.
Here is the maths I put together, feel free to comment at the bottom of this post.
Cost of gas: $0.017 / Mj
Price different between units: $700
$700 ÷ $0.017 = 41176 Mj (This is how much gas you can buy with $700.)
Eco+ model saves: 22 Mj/Hr
41176 Mj ÷ 22 Mj = 1871.6 Hours (Hours gain by using the new unit)
Now, with this figure, you need to find out how many hours your house hold uses hot water a day. Say you have 10 minutes showers, for a household of 4, so 40 mins per day.
Washing machine takes 5 minutes to fill 3 times a week, dishwasher takes 10 minutes to fill and rinse 3 times a week.
Therefore, here are the weekly minutes added up
(40 x 7)+(5 x 3)+(10 x 3) = 325 mins
1871 x 60 mins ÷ 325 mins = 345 weeks
And, finally, 52 weeks a year
345 ÷ 52 = 6.6 year
In this example, it will take you 6.6 years to recoup the initial cost. Of course, the numbers will change massively if you use have a longer shower everyday. This calculation is not taking inflation into account. Otherwise, I can write a book on it.
Do you agree with my calculation?
Do you pay 1.7c ($0.017) per MJ?? I would have thought that 17c/MJ would be a more realistic number. In which case the difference is 4,117.6MJ or 187.16Hrs or 35.5Weeks.
I’d say it’s a good deal. (it is 12.4% more efficient, so that gives an indication of the payback too.)
Cheers
Tyson
Tyson, I have just checked my old gas bill dated Jan-2011.
Gas Consumption 2496MJ @ $0.01796 = $44.83
So it is 1.796 cent per MJ.
Hi Eric
Formula seems ok, though the numbers would be interesting should the price of gas start going up.
Cheers.
The gas price need to goes up a long way before it is worthwhile to consider. At the same time, the gas unit may cost more too.
You are assuming your shower uses 26L per minute. It would probably use closer to 10L per minute. Therefore a 10 minute shower would use roughly 11 MJ of gas for the eco+.