UFH: Omit beneath Island\Cupboard or not?

sas

Hi,

I'm told that it is preferable to not put UFH pipes beneath anything that will be used to store food\garbage.

In my case we've a big island so we'd be omitting that.

My problem is that these areas aren't thermally broken from the rest of the screed so surely the heat will conduct anyway?

I'd prefer to put it everywhere but don't want to be chucking food out more regularly.

Thoughts please?

SAS

Mike2006

Correct. Leave it out where you have kitchen units, island and most importantly, your fridge freezer. You dont want to be heating the floor under your fridge freezer just for the freezer/fridge to have to work harder to keep the temp inside the fridge at its ambient.

You will obviously get some cross over of temp but it will be minimal so not an issue.

Mike.

Yes, omit from under units and other static objects.

creedp

sas wrote: »

Hi,

I'm told that it is preferable to not put UFH pipes beneath anything that will be used to store food\garbage.

In my case we've a big island so we'd be omitting that.

My problem is that these areas aren't thermally broken from the rest of the screed so surely the heat will conduct anyway?

I'd prefer to put it everywhere but don't want to be chucking food out more regularly.

Thoughts please?

SAS

Given my contributions to date its clear I would be the last person to advise anyone but anyway!! I would agree preferably not to put pipes under kitchen units but in some cases with large islands/L shaped kitchens its difficult to avoid completely. I know in my case the pipes did go under the island and kitchen units in places to facilitate an orderly flow and return of pipes but I would agree with you point re conduction and also to the fact that the air in the room is going to be 20c or more in any case and therefore the differential from the heat emitted from the floor under the units will not be so great. Also the units are raised off the floor and therefore with convection this additional heat will be dissapated. By the way did anyone ever put their hand to the back of a fridge and find that the heat from the fridge was far in excess on the heat in the room so Im not sure how much of an additional impact will UFH have. What's really NB is to have a A rated fridge which operates efficiently irrespective of the temp of the room, otherwise even during the non heating season it will have to work a lot harder to maintain the differential between the ambient airtemp and that required inside the fridge.

A thought also might be to place a sheet of foil insulation over UFH pipes under kitchen units to inhibit the heating on the screed in this area. May not be worth a damm .....

BryanF

Mike2006 wrote: »

Correct. Leave it out where you have kitchen units, island and most importantly, your fridge freezer. You dont want to be heating the floor under your fridge freezer just for the freezer/fridge to have to work harder to keep the temp inside the fridge at its ambient.

You will obviously get some cross over of temp but it will be minimal so not an issue.

Mike.

i've seen a home where a separate flue has been taken out from the rear of the fridge/freezer and the unit sealed air-tight, so that the units cooling pump is not working at room temp all the time

BigGeorge

If you are integrating the fridge or freezer, make sure that there are vents in the kickboard under the unit to allow air in /out

Do-more

I've seen a number of passive house designs which include a naturally cooled pantry, too late for that?

sas

BigGeorge wrote: »

If you are integrating the fridge or freezer, make sure that there are vents in the kickboard under the unit to allow air in /out

Funnily enough I only became aware of these last week. It comes as standard with the snazzy german kitchen herself got to pick.

sas

Do-more wrote: »

I've seen a number of passive house designs which include a naturally cooled pantry, too late for that?

Not sure, I've no idea what you are talking about

Mellor

If it was abig island with food storage i'f omit the heating.
It is was a narrow island, that was open or semi-open below, i'd include it.

Do-more

sas wrote: »

Not sure, I've no idea what you are talking about

A small room or a large cupboard which is well insulated with it's own air supply to outdoors and with an air-tight door, so that it is effectively outside the building envelope.

Best located on a north facing wall and with no window.

It helps to have the shelves in a cold material such as slate.

The temperature in this storage area will sit a little above ambient outdoor temp. so except in a heat wave it will be much better for storing food in than your standard kitchen cupboards.

Google for design tips.

Poor Uncle Tom

Do-more wrote: »

A small room or a large cupboard which is well insulated with it's own air supply to outdoors and with an air-tight door, so that it is effectively outside the building envelope.

Best located on a north facing wall and with no window.

It helps to have the shelves in a cold material such as slate.

The temperature in this storage area will sit a little above ambient outdoor temp. so except in a heat wave it will be much better for storing food in than your standard kitchen cupboards.

Google for design tips.

I've provided one in the last few houses I've designed as well.

Do-more

Do-more wrote: »

A small room or a large cupboard which is well insulated with it's own air supply to outdoors and with an air-tight door, so that it is effectively outside the building envelope.

Best located on a north facing wall and with no window.

It helps to have the shelves in a cold material such as slate.

The temperature in this storage area will sit a little above ambient outdoor temp. so except in a heat wave it will be much better for storing food in than your standard kitchen cupboards.

Google for design tips.

I had intended to build in one of those, but it got "forgotten" later on during the build. Wish I'd put it in now!

sas

Do-more wrote: »

A small room or a large cupboard which is well insulated with it's own air supply to outdoors and with an air-tight door, so that it is effectively outside the building envelope.

Best located on a north facing wall and with no window.

It helps to have the shelves in a cold material such as slate.

The temperature in this storage area will sit a little above ambient outdoor temp. so except in a heat wave it will be much better for storing food in than your standard kitchen cupboards.

Google for design tips.

I'm open to correction here but this sounds equivalent (from a PHPP view point) to a cold lobby inside the body of the house. This is consider bad in the PHPP manual.

As I'm aiming for certified passive, I couldn't have accomadated this I believe.

Do-more

sas wrote: »

I'm open to correction here but this sounds equivalent (from a PHPP view point) to a cold lobby inside the body of the house. This is consider bad in the PHPP manual.

As I'm aiming for certified passive, I couldn't have accomadated this I believe.

Possibly so, I can't remember if the ones I have come across are in certified houses or not, best to consult with your PHPP designer about the implications.

sas

Do-more wrote: »

Possibly so, I can't remember if the ones I have come across are in certified houses or not, best to consult with your PHPP designer about the implications.

Too late in the game for me either way I'm afraid.

NIce idea though.

creedp

Deleted User wrote: »

I had intended to build in one of those, but it got "forgotten" later on during the build. Wish I'd put it in now!

Sounds like a snazzy idea and another one I hadn't heard of before today. In terms of priorities though I would have thought that its not something to get unduly hot and bothered about unless maybe other peoples dining habbits are different to mine but I wouldn't have a whole lot of food in the house that would require such careful storage before it was consumed. The weekly shop is just that the food for the week and it it very easy to maintain that in good quality in std units.

creedp

creedp wrote: »

Sounds like a snazzy idea and another one I hadn't heard of before today. In terms of priorities though I would have thought that its not something to get unduly hot and bothered about unless maybe other peoples dining habbits are different to mine but I wouldn't have a whole lot of food in the house that would require such careful storage before it was consumed. The weekly shop is just that the food for the week and it it very easy to maintain that in good quality in std units.

We've recently started growing our own, such a storage are would have been good.
As it is no real issue as the garage is just as good.

Do-more

It's really an old idea that has been brought back to life. A cold pantry was a common idea before refrigeration became common place.

I'm debating whether it's worth the effort myself, but I find vegetables these days particularly hard to store in a warm house, carrots seem to go to mush in no length and there just isn't room in my fridge for a 4 stone sack of spuds!

sas

Do-more wrote: »

It's really an old idea that has been brought back to life. A cold pantry was a common idea before refrigeration became common place.

I'm debating whether it's worth the effort myself, but I find vegetables these days particularly hard to store in a warm house, carrots seem to go to mush in no length and there just isn't room in my fridge for a 4 stone sack of spuds!

I'm with DolanBaker on this one. I've a big garage that I planned on storing my aspirational home grown veg in.

Bruthal

creedp wrote: »

By the way did anyone ever put their hand to the back of a fridge and find that the heat from the fridge was far in excess on the heat in the room so Im not sure how much of an additional impact will UFH have. What's really NB is to have a A rated fridge which operates efficiently irrespective of the temp of the room, otherwise even during the non heating season it will have to work a lot harder to maintain the differential between the ambient airtemp and that required inside the fridge.

Thats the condensor of the fridge, where the refrigerant is compressed into a liquid, so releasing its heat absorbed when it evaporated in the evaporator. The lower the air temp of the ambient air around the condensor, the easier the heat is to release from the condensor. So the warmer the air around the fridge, the more work it has to do, irrespective of it being A rated. A rated will just be more efficient than non a A rated unit. It will still have to do more work in warmer air.

A thought also might be to place a sheet of foil insulation over UFH pipes under kitchen units to inhibit the heating on the screed in this area. May not be worth a damm .....

This would probably work well if they are properly insulated in areas not requiring heat alright, if going under a large area was hard to avoid.

sydthebeat

creedp wrote: »

A thought also might be to place a sheet of foil insulation over UFH pipes under kitchen units to inhibit the heating on the screed in this area. May not be worth a damm .....

nah, the concrete would react with and break down the aluminium foil... waste of time IMHO

Mellor

Plus UFH pipes heat by conduction, not radiation which is what reflective foils reduce

creedp

Mellor wrote: »

Plus UFH pipes heat by conduction, not radiation which is what reflective foils reduce

As suspected .. the simple ones are just that ...simple! Given that conduction rather than radiation is the issue with UFH I presume in any case the way to reduce the effect of UFH under units is to store perishable foods in the uppermost parts of units as these will be cooler that those parts nearest to the floor. Put the old saucepans on the lower levels as it will not be of any harm to them. Also I agree with comments earlier re storage of fresh veg etc .. it will be the garage for me. Must make use of it somehow.

Re: the A-rated issue, everything else being equal, its preferable to purchase an A-rated appliance than not. Point taken that the higher the ambient temp the harder the fridge will have to work but an a-rated fridge will work more efficiently in any given environment. Of course the alternative is to turn down the termostat a couple of degrees. Unfortunately a bit counter intitutive given the amount of money spent on keeping the temp high. Also you may well find yourself outside the door double quick enjoying the real cold!!

Bruthal

Not too many cylinders or HW pipes are inslated with tin foil though.