Combining Seperate ASHP and Oil Boiler

[ChrisDL]

Evening all,

 

A few weeks ago with the help of this forum I managed to get my head around my UFH requirements, link here, Thanks to @JohnMo @Adsibob @jack . Now I am looking for help regarding combining a ASHP with a backup oil boiler.

 

Should state, we are off grid, and although we are installing a very large PV array - electricity will be our limitation in winter and hence the need for the back up oil. If anyone wants to see my heat calculations/energy requirements click here. 

 

So my first question is does anyone know of a way to control a ASHP by way of battery level or PV generation or a ASHP with the ability built in? All the ASHP I have looked at advertise a back up facility based on outside temperature. My first thoughts were I could completely switch off the the ASHP by automation when the batteries are depleted past a certain level... but I am wondering whether ASHP would suffer from being turned off/on like this?

 

Second question, assuming I can make a ASHP work, is regarding the rest of the components. I should trust my plumber... but I would like a understanding. 

 

After much deliberation and reading on this forum I have decided on installing a UVC rather than a thermal store but I am a unsure on the buffer requirements. Below is my bare bones understanding. Do I need a buffer between the boiler/ASHP and UVC as well?

 

Also out of interest if I decided to add a biomass boiler to the design instead/with would I need a buffer then before the UVC or before everything else?

 

 

[JohnMo]

You could manage the ASHP, with something that could make or break a relay from the battery based on available power, and have the relay within a thermostat loop back to the heat pump.  So a good signal from battery would initiate the relay and if there is a thermostat call for heat, the heat pump would be allowed to start.  Conversely, if the relay is not made, due to battery not being available the thermostat call for heat doesn't make it to the heat pump.

 

[ChrisDL]

9 hours ago, JohnMo said:

You could manage the ASHP, with something that could make or break a relay from the battery based on available power, and have the relay within a thermostat loop back to the heat pump.  So a good signal from battery would initiate the relay and if there is a thermostat call for heat, the heat pump would be allowed to start.  Conversely, if the relay is not made, due to battery not being available the thermostat call for heat doesn't make it to the heat pump.

 

This sounds simple and effective. Ideal. 👍

[ChrisDL]

With respects to Zoning UFH, would people recommend minimum as possible? I was thinking of running the entire downstairs as one zone. But upstairs individual thermostats for each bedroom. Depending on preference I guess.