ASHP - to buffer or not to buffer

[wiffola]

Hi Guys,

You all know me by now...I'm looking at an ASHP to replace my LPG boiler blah blah blah. Thought this warranted a new thread so others out there can easily get to the juice info.

Ok, again, I'm getting mixed thoughts on this one...

I'm only looking at inverter based air source heat pumps..do I need a buffer?

We haven't got any space in the house but we could put a loft hatch in and put the buffer in the loft above the airing cupboard where the thermal store will be. Budget is being stretched already.

DanFoss say it's recommended, 2 ecodan/danfoss installers say you dont need it, another installer says its essential, another says see how it performs then add it...my heads going to explode.

Please help.

 

[Corgigrouch]

Yes.

When it is cold and damp outside, ice will form on the heat exchanger and will clog it. The out door unit then needs to defrost itself. To defrost, the unit needs the heat from the water in the heating system, if you don't have a buffer tank then it will draw heat from your already tepid radiators and they will lose their temperature.... If you have a buffer tank then there will be a larger reserve for the unit to draw on and should defrost better..

Have you calculated the heat requirement of your house? will the unit be big enough, will it then be big enough when the temperature is minus five?

 

[Biggles..]

Fit the Sanyo, twin it with the ACV store,job done with one very good product.

If your still getting mixed messages and the people quoting can't help you out then there not the installers for you.

 

[DeltaT2]

Yes.

When it is cold and damp outside, ice will form on the heat exchanger and will clog it. The out door unit then needs to defrost itself. To defrost, the unit needs the heat from the water in the heating system, if you don't have a buffer tank then it will draw heat from your already tepid radiators and they will lose their temperature.... If you have a buffer tank then there will be a larger reserve for the unit to draw on and should defrost better..

Have you calculated the heat requirement of your house? will the unit be big enough, will it then be big enough when the temperature is minus five?

100% correct!!! Oh the smoke & mirrors that are used by the used car Greenwash salesmen!!
Don't fit a ASHP, fit a log boiler of some kind..........You have been warned!!

 

[wiffola]

Fit the Sanyo, twin it with the ACV store,job done with one very good product.

Thanks - when you say use AVC store...do you mean use the AVC as the thermal store and then no buffer? Does this product cover thermal store and buffer needs? i.e. tank within a tank

Sorry I'm confused. A link would be good to the actual product you are refering to.

Is this what you mean http://www.acv-uk.com/slme.htm

DeltaT2 - yep log boiler will be most effecient but the whole hassle is not for me. Not enough space and not enough time. However, I do still have some installers booked, they just keep failing to find our damn house!

 

[Biggles..]

He Sanyo is designed to be ideally twinned with its own thermal store(acts as a buffer), this is manufactured by ACV at sanyo's request.

You can use another buffer/thermal store but you'll need the ACC-connect

Check out sanyo's website as to what the product is and why it's better than a HFC gassed heat pump.