Boiler-Heat Pump Hybrids

[JohnMo]

https://en.econostrum.info/uk-homes-could-adopt-boiler-heat-pump-hybrids/

 

So at last the UK can use hybrid systems, hopefully with a proper grant. Easy to get the rubbish housing stock to reduce the CO2 emissions by a big margin. No internal heating system changes needed, 80 to 90% of the heating is done by heat pump the cold period by gas etc. No defrosting required on the heat pump killing efficiency and making it more expensive to run.

 

Discuss

[SteamyTea]

1 hour ago, JohnMo said:

Discuss

An environmental disaster, only marginally better than doing nothing.

Not going to be cheap either, and will be abused by many sales orientated installers.

If some are really 'hydrogen ready' then that is environmentally worse than burning natural gas.

 

The only real solutions are to raise the price of energy though carbon taxes and put a supplementary tax on house sales based on kWh.m^-2.year^-1 usage (that data is easy enough to come by).

There is more than enough free equity in the property market to either thermally upgrade or take a hit on the selling price.

[JohnMo]

15 minutes ago, SteamyTea said:

supplementary tax on house sales

That would work for me I'm on about my 10th house. But many just don't move from one decade to the next. So they would just stay as they are, no incentive for the many.

 

15 minutes ago, SteamyTea said:

An environmental disaster, only marginally better than doing nothing.

What makes you say that? Zero need to switch to boiler until it hits about 3 degs. How many days a year do you get below that?

 

15 minutes ago, SteamyTea said:

Not going to be cheap either,

daikin hydro split pump tee'ed to the existing system. Parts just over £2k. No need for a cylinder either.

 

 

[ReedRichards]

1 hour ago, JohnMo said:

What makes you say that? Zero need to switch to boiler until it hits about 3 degs.

 But if you get a hybrid system are you going to bother to change your radiators?  It will seem like too much trouble and expense for many people so that 3 degs might be 10 degs.

[JohnMo]

4 minutes ago, ReedRichards said:

hybrid system are you going to bother to change your radiators

No need, so why would you. You just need a small 4kW heat pump and it tees into existing system.

[JamesPa]

3 hours ago, JohnMo said:

3 hours ago, SteamyTea said:

An environmental disaster, only marginally better than doing nothing.

What makes you say that? Zero need to switch to boiler until it hits about 3 degs. How many days a year do you get below that?

Depends on how it is set up!

 

Since the introduction of condensing boilers the industry has ignored the fact that, to work as designed, they need to be set up with a sufficiently low return temperature that they actually condense.  Why?  Because its easy for the installer to whack it up to max and leave TRVs to sort the mess out.  

 

Any guess what will happen with hybrid systems?  My bet is on installing the cheapest possible heat pump with the most rubbish possible controls, a buffer tank to provide hydronic separation/poor performance, and setting it up so the boiler does most of the work then pocketing any grant available.  Furthermore those of us who have gone for a heat pump risk losing out because the political incentive to fax the electricity/gas price ratio will be reduced.

 

From a purely technical point of view in some circumstances I tend to think its not a wholly bad idea, my concern is the practice.  

 

 

Edited 3 hours ago by JamesPa