Ashp, ufh and fancoils. Help!

[lizzieuk1]

So, I'm going round in circles trying to sort this out. It is seriously stressing my nerves! 

 

Plan was to have an ashp with ufh on gf then use fancoils on ff&sf so we can have top up heating & some Cooling if needed in warm summers.  Sounds simple but, No!

I'm still not sure we will need any extra heating upstairs (ICF build, aiming for very good air tightness etc etc) but too unsure to not put any in and would also like the option to cool if needed. 

 

The installer we've been working with is very comfortable with ashp and ufh, he is keen on the Panasonic aquarea as is a registered Panasonic supplier and thinks they will fit our scenario well.

Fair enough, I know they are more expensive than some but also reputed to be a good ashp and, Panasonic do make multi room fancoils which would go well with our design for ff&sf. 

 

However, he seems to be struggling to get a design solution for the fancoil units. I'm not sure why! 

His latest email has said that, having spoken to Oceanair (i contacted them to see if they could help and pointed him to them to see if he could get a design sorted as Panasonic werent being very helpful!) the response he's had is that they're not ideal for heat/cool as require a much larger power input for cooling, I've not got the detail on why yet but will once I speak to him.

 

Surely that's what fancoils do well??

Or, maybe its the ashp supply to them for cooling that's the issue as we have a heat loss of around 4kw for heating requirement 🤔

 

Can anyone please help me find someone who can offer a solution? I'm going round in circles here!

None of the options are cheap but if we're spending large amounts we want a really good system that does everything we need! 

 

Maybe we should get a separate A2A system for ff&sf to run aircon but seems nuts if we can use the ashp.

🤯😩

 

 

[SteamyTea]

Have you had room by room heat loss calculations done yet. That is the key part.

The reason that you may need a bigger cooling load is because of outside air temperatures.

In winter, most of the time, you will need a temperature difference of about 12°C (8°C outside, 20°C inside).

Summer it may be 15°C delta (30°C outside, 20°C inside, or lower the n bedrooms). You then have to add on the solar gain, which when the sun is lower in the sky, can still be 600W/m² through the windows.

 

It is possible to set up a UFH/FC system to run as one zone, with just the airflow through the fancoil units being modulated, though this may get noisy in the bedrooms.

 

The heat loss calculation is the important thing to get to grips with first, that will tell you what is needed.

[JohnMo]

Others will be along soon and tell you I don't know what I'm talking about. But having had UFH cooling for a few years plus a fan coil. I do have some actual experience.

 

I would look for simple install, fan coils will compensate for over sizing by varying it's fan speed down (good, less drafts, less noise etc). 

 

So size fan coils for heating and then actually install one size bigger ones to allow for cooling. Then operate the system as a single zone on a single flow temp in cooling (16-17 degs) and WC for heating. 

 

This may not be perfect, but will give you a comfortable house year round and good performance (CoP and EER).

[SimonD]

4 hours ago, lizzieuk1 said:

His latest email has said that, having spoken to Oceanair (i contacted them to see if they could help and pointed him to them to see if he could get a design sorted as Panasonic werent being very helpful!) the response he's had is that they're not ideal for heat/cool as require a much larger power input for cooling, I've not got the detail on why yet but will once I speak to him.

 

Surely that's what fancoils do well??

Or, maybe its the ashp supply to them for cooling that's the issue as we have a heat loss of around 4kw for heating requirement 🤔

 

Is it that Panasonic are not being helpful for him or for you? So far my experience of Panasonic tech (I'm a Panasonic pro installer too) has been very good, and when I needed an extra push for some assistance, my rep was amazing and followed through on all promises. So I'm a bit surprised to hear this. 

The problem is that we really need to know more details about the design issues and what they're referring to as much more power, which will depend on the design parameters too.