Unipipe v Danfoss UFH

L.Demps

Hi all,
Our plumber has recommended Danfoss UFH pipes to go with our Danfoss geothermal heat pump. Apparently they are made of the same material as unipipe but it's half the price of unipipe. There will be 4 stats with this system as the heat pump is "intelligent" and knows when and where the heat is needed.
Has anyone experience of using Danfoss UFH pipes? I read lots about unipipe but am finding it difficult to research Danfoss.
Thanks,
Lisa

jj58

L.Demps wrote: »

Hi all,
Our plumber has recommended Danfoss UFH pipes to go with our Danfoss geothermal heat pump. Apparently they are made of the same material as unipipe but it's half the price of unipipe. There will be 4 stats with this system as the heat pump is "intelligent" and knows when and where the heat is needed.
Has anyone experience of using Danfoss UFH pipes? I read lots about unipipe but am finding it difficult to research Danfoss.
Thanks,
Lisa

As long as pipe is DGVW certified its perfect

L.Demps

Thanks for that I'll check it out.

Tommyboy08

L.Demps wrote: »

Hi all,
Our plumber has recommended Danfoss UFH pipes to go with our Danfoss geothermal heat pump. Apparently they are made of the same material as unipipe but it's half the price of unipipe. There will be 4 stats with this system as the heat pump is "intelligent" and knows when and where the heat is needed.
Has anyone experience of using Danfoss UFH pipes? I read lots about unipipe but am finding it difficult to research Danfoss.
Thanks,
Lisa

If the heat pump is intelligent, then why is their four stats, the heat pump intelligence is its weather compensation controller, in order for this to work correctly there should not be any stats inside your house,
Also if he has to use stats, then make sure he's fitting a correctly sized buffer tank or your going to have higher running costs than you should have,

Outkast_IRE

Tommyboy08 wrote: »

If the heat pump is intelligent, then why is their four stats, the heat pump intelligence is its weather compensation controller, in order for this to work correctly there should not be any stats inside your house,

Don't think your correct on this point, the danfoss system he is referring to is the "Danfoss Link" system. To the best of my knowledge its this control system that is "intelligent" and it is basically a fancy controller linked to the various stats throughout the house, and if using all danfoss gear it can be linked back to the heat pump too.

Curious Geroge

I've been talking to the Danfoss guys re an Air 2 Water unit and danfoss underfloor has never come up, just multi core as standard from all the suppliers. Can anyone tell me the difference ?

Condenser

Outkast_IRE wrote: »

Don't think your correct on this point, the danfoss system he is referring to is the "Danfoss Link" system. To the best of my knowledge its this control system that is "intelligent" and it is basically a fancy controller linked to the various stats throughout the house, and if using all danfoss gear it can be linked back to the heat pump too.

You shouldn't have stats on any heat pump system unless theres a buffer which would make their use in the system above the opposite of intelligent.

Condenser

Curious Geroge wrote: »

I've been talking to the Danfoss guys re an Air 2 Water unit and danfoss underfloor has never come up, just multi core as standard from all the suppliers. Can anyone tell me the difference ?

Theres very little difference between any of the ufh pipes available besides the chinese stuff. The main things about ufh is the system design (loop length and spacing) and emissivity of the pipe.
PE-RT and PEX-c and PB all would have higher output per metre than the alu pex that many recommend in pipes of the same dimensions.

fclauson

Condenser wrote: »

You shouldn't have stats on any heat pump system unless theres a buffer which would make their use in the system above the opposite of intelligent.

totally agree - we have none across the whole hose

we do have one challenge - which I am still thinking about

Take the scenario warm day,cold night.
Night time set point say (and I am guessing a bit here) - out side temp 4C - set point 27C
Day time set point (calculated by compensator) - out side temp 14C - set point 21C

How do I stop the HP running over night (when I want to use cheap electric) because tomorrow will be warm and not need the heat which gets pushed in over night (due to solar gain in the house)

There is a need for an intelligent "planning" system for the HP to forward look say two days given the lambda delay (heat loss) of a well insulated/passive house & the forecast of the upcoming weather

ideas welcome

Outkast_IRE

Condenser wrote: »

You shouldn't have stats on any heat pump system unless theres a buffer which would make their use in the system above the opposite of intelligent.

They seem to be pushing this "link" intelligent control system with their heat pumps.

Here is their own literature http://heating.danfoss.com/PCMPDF/Danfoss_Link_HeatPumps_EndUser_v4.pdf

I assume it must be thermostat control linked to motorised valve as the literature says Individual control in each room.

Wonder why they are pushing a system that will bring down the efficiency of the heat pump /

Outkast_IRE

Condenser wrote: »

You shouldn't have stats on any heat pump system unless theres a buffer which would make their use in the system above the opposite of intelligent.

I was under the impression that they were using the thermostats in the room to control the temps the heat pump was operating at but from reading their own literature, I have since seen this isn't the case, and they are simply thermostats with a fancy controller.

Condenser

fclauson wrote: »

totally agree - we have none across the whole hose

we do have one challenge - which I am still thinking about

Take the scenario warm day,cold night.
Night time set point say (and I am guessing a bit here) - out side temp 4C - set point 27C
Day time set point (calculated by compensator) - out side temp 14C - set point 21C

How do I stop the HP running over night (when I want to use cheap electric) because tomorrow will be warm and not need the heat which gets pushed in over night (due to solar gain in the house)

There is a need for an intelligent "planning" system for the HP to forward look say two days given the lambda delay (heat loss) of a well insulated/passive house & the forecast of the upcoming weather

ideas welcome

Use the night set back, you don't require heat at night as you're under a duvet and warming a house at night only increases heat loss as the differential between inside and out is at its max so using night rate is a bit of a fallacy and only required if your heat pump is hard on electricity.

fclauson

Condenser wrote: »

Use the night set back, you don't require heat at night as you're under a duvet and warming a house at night only increases heat loss as the differential between inside and out is at its max so using night rate is a bit of a fallacy and only required if your heat pump is hard on electricity.

ok - but if you want to benefit from 9c per unit vs 18c then night rate makes sense

If one is trying to keep the superstructure at a constant (ish) temp then topping it up during cheap rate makes sense. As an example post storm Darwin the house dropped 1+ degrees over 2 days - I was tempted to leave it off for a few days to see how far it dropped but did not want the grief from my better half.

its just a very fine balance over adding heat vs solar gain

Condenser

fclauson wrote: »

ok - but if you want to benefit from 9c per unit vs 18c then night rate makes sense

If one is trying to keep the superstructure at a constant (ish) temp then topping it up during cheap rate makes sense. As an example post storm Darwin the house dropped 1+ degrees over 2 days - I was tempted to leave it off for a few days to see how far it dropped but did not want the grief from my better half.

its just a very fine balance over adding heat vs solar gain

Your day rate is more expensive if you avail of night rate so couple that to the additional heat loss and the gain is next to nothing if anything at all. If there is a significant difference in a house as well insulated as yours then the heat pump isn't up to much.
You also need to consider that you have an Air to water and the cooler temps of night also decrease your COP so you really shouldn't be running at night at all if possible.

Curious Geroge

Having installed a Danfoss AQ, would you do it again or is there better available ?

fclauson

Curious Geroge wrote: »

Having installed a Danfoss AQ, would you do it again or is there better available ?

The HP side is fine - I think in a Passive House there is much more work needed on the control side to better match demand vs the was a Passive House needs heat

but at a heating bill of a couple of hundred euro per year then I am V happy compared to my last house at 2 to 3 fills @ €700 per time

Curious Geroge

fclauson wrote: »

The HP side is fine - I think in a Passive House there is much more work needed on the control side to better match demand vs the was a Passive House needs heat

but at a heating bill of a couple of hundred euro per year then I am V happy compared to my last house at 2 to 3 fills @ €700 per time

There is the Danfoss Link that may be more control but not yet available in Ireland and the UK I'm told.