ASHP v Gas boiler

[epsilonGreedy]

45 minutes ago, K78 said:

Yet you never see any of this on the news. Just the rising sea levels and melting glaciers. 

 

 

That is because the era of Western culture with its free speech and free thought is over, we now live in a modern tyranny regulated by tribal belief mechanisms and a fear that "hate speech" heretics lurk around every corner. We had a good 250 year sprint of achievement since the Edinburgh Enlightenment, China and India are now in charge of humanity's destiny. We pontificate for decades over a 3rd runway for Heathrow, whereas in 24 hours China can place a city the size of London in isolated medical quarantine.

Edited January 23, 2020 by epsilonGreedy

[K78]

32 minutes ago, epsilonGreedy said:

 

That is because the era of Western culture with its free speech and free thought is over, we now live in a modern tyranny regulated by tribal belief mechanisms and a fear that "hate speech" heretics lurk around every corner. We had a good 250 year sprint of achievement since the Edinburgh Enlightenment, China and India are now in charge of humanity's destiny. We pontificate for decades over a 3rd runway for Heathrow, whereas in 24 hours China can place a city the size of London in isolated medical quarantine.

I honestly believe most of these idiots only exist on twitter and in organised mobs.

 

My ex girlfriend is 23. None of her friends were “woke”. They all think it is ridiculous as the rest of us. 
 

When you look at what China and India are pumping into the atmosphere. All of our best efforts to be green make no difference. We make less difference than one arrogant, pig faced child. Who has not worked a day in her life. 
 

The world has changed massively in the last 5 years. Recent signs of improvement though. Everyone has had enough of media driven dross. 

[Jeremy Harris]

3 hours ago, epsilonGreedy said:

 

Worth noting that even the leading eco self builders on this forum concede they do not achieve 100% heating off night time tariffs. Best assume 70/30 split (night/day) in your ££ calcs or worse if your build fall well short of passiv house standards.

 

 

I'm most definitely not an "eco self-builder",  by any stretch of anyone's imagination, but our heating is so far running 100% from night time E7, using an ASHP.  We've not had to turn the heating on during the day yet, even during the recent fairly cold spell here, where the night  time temperature was fairly consistently well below zero for a few days.   It's possible we may need to run the heating during the day before the winter is out, but frankly I doubt it, given that the house seems to stay warm (between 21.5°C and 22.5°C) just fine with the heating only running during the midnight to 7 am period.

 

If I was willing to give up the simple thermostat control, and opt for something predictive, like the system @TerryE uses, then I could almost certainly guarantee that the heating would never, ever, need to use peak rate electricity.  The only flaw with having a simple room thermostat is that it doesn't know what's going to happen in a few hours time.  Knowing that outside temperature is likely to increase the following day would allow the overnight heat input to be turned down, and similarly, knowing the temperature was likely to decrease the following day would allow the heat input to be increased.  Not really sure it would be worth the effort, though, as the house seems comfortable enough with just the simple thermostat control and time switch.

[SteamyTea]

48 minutes ago, K78 said:

When you look at what China and India are pumping into the atmosphere

They are making a lot of goods for 'us' though.

And rather than look at national boundaries, we need to look at per capita and population density.

But even that is tricky as it makes Australia, with relatively little population for the country size look good, but they supply a lot of coal and iron ore for India and China.

[TerryE]

At  the moment we are running at about 70:30 E7 to peak rate, but that 30 % has little to do with direct space heating. It's all the other energy use: cooking, lighting, appliances etc., though except for HW going down the plug hole, this generates waste heat that does eventually heat the environment.  Because we are currently limited to 2.88 kW input to our UFH, when the average outside temp falls below about 4°C my heating control will top up using peak rate electricity, but this is a tiny % of our total charges. We run our ground floor at ~22.7 ± ½°C ripple.  The upstairs floors are a degree or so cooler.

[Ferdinand]

On 23/01/2020 at 13:37, epsilonGreedy said:

 

That is because the era of Western culture with its free speech and free thought is over, we now live in a modern tyranny regulated by tribal belief mechanisms and a fear that "hate speech" heretics lurk around every corner. We had a good 250 year sprint of achievement since the Edinburgh Enlightenment, China and India are now in charge of humanity's destiny. We pontificate for decades over a 3rd runway for Heathrow, whereas in 24 hours China can place a city the size of London in isolated medical quarantine.

 

Equally in a totaltitarian state eg china one central poor decision can kill 10 million people Just Like That, with no checks and balances.

 

See eg iron Rice Bowl or what happens when district heating schemes in Moscow break down.

 

Personally I think China will end up with some structures analagous to democratic checks and balances.

[SteamyTea]

On 23/01/2020 at 13:37, epsilonGreedy said:

We pontificate for decades over a 3rd runway for Heathrow, whereas in 24 hours China can place a city the size of London in isolated medical quarantine.

Not really comparing similar things, but I was on one of the last flights out of Toronto when the SARS outbreak happened in 2003.  Air travel was shut down after that.

 

I am happy to stick to Hanlon's razor.

[davejura]

We wanted to put a gas system in our new build, but was told if we did we would then need solar PV panels to pass the SAP calcs. So ASHP it is as the gas / PV combo would be more expensive.

[Simplysimon]

one other thing we had against a gas combi boiler was the hot water runs, turn on the hot tap, wait, use, turn off tap. turn on hot tap, may get warm water then cold, finally hot.

[epsilonGreedy]

43 minutes ago, Simplysimon said:

one other thing we had against a gas combi boiler was the hot water runs, turn on the hot tap, wait, use, turn off tap. turn on hot tap, may get warm water then cold, finally hot.

 

 

The present static caravan for our self build has been my first experience of a combi boiler for hotwater.  The initial wait for the first delivery of hotwater does not bother me and that is from a 21Kw model with very high water pressure. However when showering the option of leaving the water running feels wasteful at near a powershower flow rate due to our good mains pressure but the alternative yo-yo temperature cycle of hot/lukewarm/cold/hot-again is a problem.

 

The hybrid Vaillant combi boiler mentioned by @Nickfromwalessounds like a solution. I would not need such a hybrid "storage" boiler to maintain its small internal tank at a hot temp over 24 hours, however I wonder if it could be reprogrammed to maintain the tank at a hot temperature for 15 minutes then if there is no further demand let the tank cool down.

[K78]

On 26/01/2020 at 14:19, davejura said:

We wanted to put a gas system in our new build, but was told if we did we would then need solar PV panels to pass the SAP calcs. So ASHP it is as the gas / PV combo would be more expensive.

Is it a large house? The new builds I’m seeing don’t have ASHP or PV?
 

I think I would prefer a combi for reliability and repair costs. I also know a few people who can fit them and sign them off. 

[epsilonGreedy]

5 hours ago, K78 said:

I think I would prefer a combi for reliability and repair costs. I also know a few people who can fit them and sign them off. 

 

 

One thing that shifted me towards considering ASHP is gas boiler servicing contracts. Over 15 years of ownership you can use typical boiler home care contract monthly rates to get an idea of cumulative costs plus if you eliminate a gas connection by all electric cooking then a gas daily standing connection charge goes as well.

[K78]

1 minute ago, epsilonGreedy said:

 

One thing that shifted me towards considering ASHP is gas boiler servicing contracts. Over 15 years of ownership you can use typical boiler home care contract monthly rates to get an idea of cumulative costs plus if you eliminate a gas connection by all electric cooking then a gas daily standing connection charge goes as well.

I have definitely not ruled a ASHP out. 
 

Ive never bothered with monthly care plans. I have always bought Worcester (last one 7 years ago), although I believe they are no longer the best option. Started dripping a few weeks back. I feared the worst but it was only a £150 fix including a service. 
 

What is the average install cost of a ASHP?

 

These eBay packages seem expensive?  https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F113774677085

[epsilonGreedy]

4 minutes ago, K78 said:

Ive never bothered with monthly care plans.

 

 

Neither did I and had 7 years trouble free usage without even an annual service.

 

The next 7 years cost about £500 in adhoc repairs.

 

My current plan is to plumb for either ASHP or LPG, but experience two winters using just those inline electric heaters and get to know the thermal performance of my new build before deciding. One downside of that plan is missing out on reclaiming the VAT.

[TerryE]

I've just done a review of our heating costs over the last calendar year.   We only use electricity and have SunAmp PVs heated only by E7 for DHW, and a Willis for UFH heating the slab of our 5 bedroom 3 storey house.  Based on my Home Automation logs, our annual (Willis) space heating costs for this last year work out at ~£380 p.a.  This would fall to around £115 p.a. if we had used an ASHP so maybe an annual saving of around £265.  We use an induction hob and 2 × electric oven/microwave for cooking (with a 2 ring Propane for backup and which we've never used in anger) so we have no other need for gas connection.

 

So there would be maybe a 10-year payback for installing an ASHP if I did this myself, plus some extra benefit if we used one with a cooling mode option for the Jul / Aug temperature peaks. 

 

We also saved a lot of money avoiding gas installation, and the annual standing charge for gas connection (~£75 p.a. in our area), and the cost of annual maintenance for a gas appliance (something that is mandatory IMO).  And note that if we did have an ASHP, then the avoidance of the gas standing charge represents an offset of some 65% of the ASHP running cost.  So in our case the gas vs ASHP argument is a no-brainer.

Edited February 3, 2020 by TerryE