Real world feel of MVHR +heat system

[Iceverge]

1 hour ago, saveasteading said:

In a domestic situation I have no experience of barefoot winter use on an unheated  tiled and well  insulated floor.

But the principle is simple enough. If the floor is 25°C or so from absorbing space heating then it won't suck heat from your feet, but that won't be an efficient process.

That's the main issue I think. Ufh is inherently warm and gives you cosy feet then spreads to the air which can be cooler.

 

Floor covering makes a lot of difference. Carpet and LVT throughout here. 

 

Efficient UFH with a floor at 25 deg won't feel much different on your toes from a well insulated slab at 20deg. Not chilly, not hot. UFH in a high flow temp situation is very nice on your feet but it's expensive to run. 

1 hour ago, saveasteading said:

I don't see any reason against having both, it's just heat transfer through pipes to the floor or to a fan.

 

Cost and complexity? 

 

[saveasteading]

15 minutes ago, Iceverge said:

expensive to run. 

I don't agree.

 

15 minutes ago, Iceverge said:

Cost and complexity? 

Air to water I think we all know about. Some of that is taken to a plenum to heat air which is pumped into the room and a duct returns it from the other end. Simple but prob not for the typical installer who buys a kit.

[Andehh]

The shoulder months are also problematic for us (!) we are in a well Insulated house (miles off passive though... 2.7 airtight, 0.11 floor, 0.22 walls, p. 14 roof).

 

We also have a huge amount of glass & very high ceilings of 3.2 to 4.2m, and regularly during shoulder months the house isn't cool enough to trigger the heating (21 - 22 degrees) , but the tiles feel cold under foot and you can actually feel quite chilly... Maybe due to the large glass?

 

As a result we actually need to force the heating to come in (set thermostats to 24 degrees) for a couple of hours to warm the tiles up.

 

We are also heavily zoned, which works well for us, as we have a very complicated design, so can fine tune the boost to rooms that need it, and leave the bedrooms etc 

[JohnMo]

1 hour ago, Andehh said:

huge amount of glass & very high ceilings of 3.2 to 4.2m, and regularly during shoulder months

We are similar, but one room is 6m high and all glass bay window 6m tall also. We started zoned to death and it just didn't work for us, at the time the boiler just suffered from short cycling. We went fully open, single zone after a lot of iterations, and full weather compensation. Halved the gas usage at the same time. Now with ASHP we operate just the same.

 

1 hour ago, Andehh said:

but the tiles feel cold under foot and you can actually feel quite chilly..

Now never feel this, full time heating also allows you to run the house way cooler, with no ill effects. In summer we just switch the heat pump to cooling to make the most of cold tiles and manage house temps.

 

1 hour ago, Andehh said:

we have a very complicated design, so can fine tune the boost to rooms that need it

The mother of poor efficiency.