System boiler & Air Source heat pump

[MOSSEP]

Hi,

Has anyone got a simple schematic for a system that uses a system boiler & Air source heat pump? It early morning and I cant get my head around it at the moment. The client will want the system boiler to cut in if the air source pump cant meet the demand in winter months.

Cheers!

Martin

 

[oz-plumber]

What sort of heating is in the property - ufh or panels, or a combination of both.?

You may need a buffer tank with an outdoor sensor connected.
When the ambient temp is high enough the ASHP may be able to cope with the heating, but getting the boiler to fire up when a greater heatload is required will probably require a tank stat set at say 50C.
When the boiler is required to heat the water, the ASHP become almost redundant.

 

[MOSSEP]

They are having UFH & radiator panels.

I'm unsure what ASHP system he is getting, but the last one I did had a buffet tank. I can't remember though whether they have additional coils in them that the system boiler could heat it via, or of the system boiler will need adding to the system in another way?

Martin

 

[oz-plumber]

Get the info and post it.

Depending on the system that is being sourced is dependent on the design of the boiler installation.

There are always options - but we need to design the system around what equipment is being supplied / recommended.

The tricky part will be hoe to control the boiler, so as not to override the ASHP and make it redundant or obsolete in the installation

 

[MOSSEP]

Thats what I was scratching my head with. I think the client is under the impression that he will just have the boiler on when its needed, not quite a simple as that though.

 

[quality]

If I were to spec the system I would go for a mitsubishi ecodan and control the whole lot from the ftc5 controller

 

[MOSSEP]

Im not sure what ASHP he is getting yet, hopefully he has discussed operation of it with the companies he is getting prices from.

Would the FTC5 controller be able to bring in the system boiler automatically then if the ASHP fails to achieve the required temperature, or heat the house within a reasonable time?

 

[macackau]

I've only ever installed Mitsubishi units, have done a few with boiler back ups. When you say radiator panels, You need to take in to account that an ASHP runs only at 55 degrees or so, not normally the heat output you would expect from a traditional boiler running rads

 

[macackau]

The ASHP should be capable of running the heating, the FTC5 will also take care of the legionella cycle on the unvented cylinder as the water will be stored at a lower temp as well

 

[MOSSEP]

I did tell him that, he needs to consider oversizing them.

 

[oz-plumber]

Im not sure what ASHP he is getting yet, hopefully he has discussed operation of it with the companies he is getting prices from.

If I was you I would start getting involved asap.
Your neck will be on the chopping block if it goes downhill after the installation.

Set up a meeting with the ASHP company rep, the owners and you and make sure everyone is on the same level with how the system is to operate and perform.

Ask the ASHP company to provide you schematics and instructions how to install their system and ask them to provide a guarantee on the performance of the system that they have specified.