Mechanical Ventilation w/Heat Recovery

Squall Leonhart

Hi,

I am looking at an MVHR system for a new build house, and I have been in touch with a supplier, who have quoted €4381.00 for supply/installation/commissioning.

The system they have recommended for the house based on drawings they received has a power consumption of 45-90W.

Can somebody please try and explain to me a little about power consumption? As it's supplying air to the house, I assume it's a 24/7 operation time. But how do I work out what it will cost in electricity to run, say, based on the ESB prices of 14.1c per unit?

I'm just looking at the total cost of this, initial costs are one thing, but running costs are important.

Thanks for all help

Squall Leonhart

Would I be right in the following calculation;

1 watt/second = 1 Joule
1 kilowatt hour = 3,600,000 Joules

Taking the upper limit of the 45-90 watt, i.e., 90w;

90 x 60 x 60 x 24 x 365
____________________
3,600,000

To give me 788.40 kW/h, @14.1c per unit (kwh),

788.4 x 0.141 (converting the cent to euro)

To give me a running cost per year, @24hr per day usage

.... €111.16??

Or, at a standard bill, every two months, €18.53 per bill?

dos29

I'd say your calculations are fairly spot on. Any units I've researched have stated running costs of approx €30-€50 a year. Your costings there are for the upper limit like you say, which would be if the unit was in boost mode for an entire year. I would reckon approx €50 p/a would be reasonably accurate, almost regardless of unit.

Squall Leonhart

Cheers for the reply dos29, glad to see that my calculations aren't totally off the wall! Like you said, that would be assuming it'd be in boost mode for a year, which naturally enough it wouldn't be!

darrenss

quick question if you dont mind what heating system will you be using
with the mhrv,starting new build soon just not sure what heating ,
thinking air to source with underfloor and maybe mhrv,cheers

Squall Leonhart

Hi darrenss,

Mains gas with a combi boiler will be the heating system

AMG86

Heating is of course important. There are 3 things to be considered simultaneously when building. They are insulation, air tightness and ventilation. Failure to address any one of them will result in problems. The better insulated and more airtight the house the less primary energy will be required. Your HRV system will help to reduce this demand further and give you fresh air 24/7.