ASHP. We've only gone and done it again!

Cardew

The oil suppliers up that way are currently wanting 66p/litre.

54p/litre is today's price for the north of Scotland from these people.

https://www.cheapoilprices.co.uk/index.php

https://www.cheapoilprices.co.uk/heating_oil_prices.php

or try these:

http://www.highlandfuels.co.uk/heating-oil

Cold goes hand in hand with damp in an old stone house which then causes deterioration of furnishings and things like the kitchen cupboards and wood worktop. A bit of warmth, 10', isn't all that much but it is enough to prevent the worst of the damp and damage whilst, hopefully, not costing too much. Pay now for heating or later for repairs....

If you have ingress of moisture, 10C or 20C room temperature IMO in an empty house is not going to prevent dampness.

Heating rooms enables the air to hold more moisture, which then condenses on cold surfaces like windows. In fact dampness is far more of a problem in tropical climates where rooms can be at 30C.

I have a single cavity detached building here that is not used much. I let the temperature drop in winter to 3C before heating comes on. If it wasn't for the bother of draining down CH boiler etc, it wouldn't matter to me it it was left completely unheated.

Nobody heats their lofts, but because they are well ventilated it is safe to store all kinds of items without them getting damaged.

If I had a dampness problem, I would use dehumidifiers when the property was empty.

TiredGeek

I've passed the oil details to our friends, thank you
They're a bit miffed at paying over the odds, maybe next time they'll do a google.

The damp issues, we found the house smelling damp over the winter months until we had the heating fitted first time. While it worked the damp smell wasn't there, when it stopped, the smell came back. No other factors were altered, no extra ventilation or anything else that could effect it, just a bit of warmth.
There's no actual moisture on the walls and no condensation on the windows so it's not "running wet" but there's a moist smell when it's been sat over winter....
Maybe it's just the warm air finding a way out and taking the smell with it

This winter will tell us more as we're fully confident that this time it'll make it through the cold spell without failing

grahamc2003

TiredGeek, well done for getting the system sorted. I'm sure any running costs will soon fade into insignificance once the rhi payments start - I expect they'll exceed your running costs by a fair margin.

Your system is really the ideal test for these things, being monitored as they are by Mitsui - hopefully you'll sail through next winter with no probs, but if you do have any, then it won't do their reputation much good (since you'd expect non-monitored systems to perform sub-optimally).

Last year (or was it two or three years ago), someone posted horrific pictures of frozen up heatpumps - I think they were in Scotland, and in a damp area with mist usually in the air in winter. Was that your old system, or someone else's?

In a way, that environment sounds like a great test for ashps - if they perform well in a cold winter when the air is full of mist, then they can perform well anywhere I expect.

Does the system interface to your pc, and collect all sorts of data? Be great to see how often the defrost kicks in. As Cardew implied, the defrosting is really a bit of a fiddle when it comes to the quoted cops - to measure those, defrosting (which I expect uses a lot of energy) is simply ignored altogether!

Anyhow, your heatpump story is compelling reading, so keep posting all the good and bad bits which unfold.

[Deleted User]

Monitoring our EcoDan (same model as tiredgeek) defrosting has not been an issue.

If the ASHP is correctly setup i.e. heat emmitters matched to heatloss with appropriate heat curve the ASHP is just ticking over even in sub zero temps i.e. the two big fans are running fairly slowly so not a large amount of air passing over the fins so minimal icing if any.

However when heating DHW to 50c [or beyond] the ASHP fans run fast increasing the risk of icing. This was when we noticed a defrost, not icing as such more like a dusting on the fins so hard to even notice. Anyway the defrost was over in mins as a result.

Experts have suggested heating DHW to 45c then boost to 50c or beyond with the imersion. This may work out cheaper in winter with longer compressor life.

I suspect old tech non inverter fixed speed ASHPs would be much more susceptible to icing...

Tiredgeek's old EcoDans were probably running flat out hence the icing and silly bills as result of incorrect install.

Just chatting in simple terms so don't flame me

TiredGeek

grahamc2003 wrote: »

Last year (or was it two or three years ago), someone posted horrific pictures of frozen up heatpumps - I think they were in Scotland, and in a damp area with mist usually in the air in winter. Was that your old system, or someone else's?

I'm sure that will have been mine
Took from first failure in November 2009 to Feb 2012 to get a resolution - removal & refund.

That's history now, looking forward to the good times

The monitoring equipment sends data back to Mitsubishi, quite a lot of parameters I believe, most of which I wouldn't understand

richardc1983

Just had a read of this very good that you managed to get things sorted out? Now the weather has turned cooler howa re things?

TiredGeek

Well, at the moment the heating hasn't done anything
Since fitting it's basically been set to frost 'stat so it's sitting there waiting 'till the interior of the house drops below 10'c then it'll turn on.
We've had a couple of nights where the outdoor has dropped down to around 1'c but so far the house hasn't dropped below 12' so nothing has happened.
Pretty soon that'll change though, I reckon it'll be coming on mid next month for short periods then by November it'll be humming away everyday maintaining the 10' we're wanting.

It's brilliant being able to log into Mitsubishi and have a look at what's happening with the heating, gives a real sense of security unlike the first system where we were just guessing if it was working or not...

We're hoping for a 2010 November again, something to properly test it

richardc1983

Forgive me for forgetting do you not actually live here?