Little update on fancoils.

[Beelbeebub]

So I fitted a reverso fan coil back last spring. Obviously it didn't get much use until recently. 

 

It's fed by a 40C underfloor circuit. The whole house is on underfloor so there is a single blending valve for the heating circuit. 

 

The fan coil was plumbed in tk replace the dud UFH circuit. The room was controlled by a thermostat (ancient danfoss unit) opening a 2 port valve. The warm water then flows and the unit's fan is switched by a slightly bodged setup triggered when the flow into the coil rises above 37C.

 

Anyway, I have a few days of data to see how the system is handling temperatures. 

 

Prior to Wednesday the hearing didn't kick in as the room never dropped below the 20C setpoint 

 

The 18C drop on Friday night was due to me setting the setpoint to setback to 18C from 10pm to 6am. This also gives an idea of the unheated performance of the room. 

 

Overall I'm pretty pleased. The unit is not running continuously, which means i could have lower flow temps. It is near silent. The biggest clue to it kicking in is the ping from the thermostat relay. 

[Beelbeebub]

Little zoom in on the 18C setback. 

[Andehh]

Interesting! What caused the dud UFH?

[Beelbeebub]

2 hours ago, Andehh said:

Interesting! What caused the dud UFH?

Long story.

 

It was a weird system from the late 90's. Basically these little rubber tubes.  The material was "santoprene" I believe. Very flexible and the company had a 50y guarentee. They went on about how it was used by NASA and in medical etc. 

 

The problem was the material became brittle when exposed to warm water with dissolved copper or iron in it (can't remember which). Space rockets and medical devices don't encounter this often!  But central heating systems...... 

 

Anyway the first pipe went after a few years, which is when my parents found all this out.  They also found the company had folded due to all the warranty claims. 

 

Anyway, the system has limped on for anther 20 years by being run at a low pressure and temperature (sub 1bar and sub 40c) but has finally given up the ghost when my father, who has dementia, decided the central heating needed topping up and forgot to turn off the filling loop. System went up to 2 bar before the pressure valve went, but not before it split multiple pipes. 

 

I took up one room and the pipes were like old plastic. You could split them.with your fingernail in places. 

 

I replaced that room with a DIY speedit pipe system. But it was a faff, so I tried another route in another room - fancoils. 

 

TLDR: don't use experimental UFH systems, stick with PEX pipe 

[G and J]

4 hours ago, Beelbeebub said:

It is near silent.

We’re looking favourably at a Reverso unit, so v pleased to hear you say it’s quiet.    Which variant did you use?