Shown below is the datasheet for my MHVR (which I'm in the middle of balancing). 

 

I'm trying to work out very simply electricity costs to run it..

 

If we go on max power (100% speed) it can consume 360W, which is 8.64kWh per day, 3153 kWh/annum.

 

At say 35p/kWh thats £3.02 /day. 

 

However mine will run at roughly 30% speed on trickle (thats as low as it goes I believe on trickle). Arbritraly thats £1 per day, . Thats seems quite a lot? 

 

Now the AEC (Annual electricity consumption) on the datasheet says 2.65kWh/100m2. We are 265m2, hence 2.65x2.65 = 7.02kWh/ annum. 

 

1051kWh (30% of 3153) vs 7.02kWh is a massive difference? Where am I interpreting it wrong as the AEC surely can't be that low.

 

Also it does say the fan speed is variable, but if its running at 30% it's running at 30% regardless of velocity at each inlet/outlet? 

 

 

 

 

 

Edited September 10, 20233 yr by SuperJohnG

You really need to use the SPI W/(m3h) figure for calculating the energy use, as long as you are not using inappropriate duct lengths or duct type, that will give the most representative energy use figure.

 

Calculate the flow rate you are likely in m3/h m, then select based on that figure. Once you are in the house the flow rates are generally to high, I halved mine, as the house most likely a couple of people rattling around a biggish house. 

Edited September 10, 20233 yr by JohnMo

We are in the house, and operating fine and inaubidle (even at night) - even though the flow rates are high (more than required at boost) at trickle.

 

Going on using the SPI. If we use 30% of the total figure of 660m3/h.

 

198 m3/h that's works out to be just around 2kW/h per day. 70p/day at 35p/kWh.

If you have a multimeter, you can check the amps pretty easily.