Alternative to AC - Might be useful going forwards

waqasahmed

QrizB said:

70sbudgie said:

What sort of efficiency does a MVHR run at? Would the two in combination reduce the energy required for heating / cooling?  Over the last couple days, the thing I have really noticed is the apparent lack of air! Opening windows that normally create a breeze was a mistake.

Here's a blog post from a major manufacturer (so they have a vested interest) that discusses some of this:
https://www.xpelair.co.uk/what-is-mvhr

Is that basically free heating / cooling? Or more so, a much more efficient use of existing heat / cooling?

If so that'd be good. Also, tbh even if it merely reduces the need for AC, that's still a win because the longer we can comfortably go without AC, the better 

QrizB

waqasahmed said:

QrizB said:

70sbudgie said:

What sort of efficiency does a MVHR run at? Would the two in combination reduce the energy required for heating / cooling?  Over the last couple days, the thing I have really noticed is the apparent lack of air! Opening windows that normally create a breeze was a mistake.

Here's a blog post from a major manufacturer (so they have a vested interest) that discusses some of this:
https://www.xpelair.co.uk/what-is-mvhr

Is that basically free heating / cooling? Or more so, a much more efficient use of existing heat / cooling?

It's part of an engineered ventilation system.

In most houses, you open a window to improve indoor air quality. Or you might have an extractor fan from your bathroom or kitchen, to help control humidity. The problem is that for a good part of the year, the temperature inside the house is significantly different to the temperature outside; when you vent air and replace it from outdoors, you're also losing heat (or, in the heights of summer, gaining it).

MVHR uses a heat exchanger to reduce these losses. In winter your exhaust air us used to pre-heat the make-up air, and in summer you can use your exhaust to cool the make-up. It's not 100% efficient but it's a lot better than not having it.

ComicGeek

You can also install cooling modules onto MVHR units, which actively cools down the supply air. Needs insulation on the supply air ducting to prevent condensation. 

The waste heat is then discharged through the MVHR exhaust system.

waqasahmed

ComicGeek said:

You can also install cooling modules onto MVHR units, which actively cools down the supply air. Needs insulation on the supply air ducting to prevent condensation. 

The waste heat is then discharged through the MVHR exhaust system.

Ooh. Both these seem quite decent