Discussion ... ASHP(Air/Air) with Solar pv ....

mgbond

Question for Zeupater and others.

I don’t really need upstairs to be as warm as down stairs so what would you think about having the PAC system for upstairs and then add one of these toshiba units for down stairs?

Or would you suggest to bin the PAC system and just get good PV install and 2xtoshiba units and have one for both floors.

Martin

Coastalwatch

mgbond wrote: »

Question for Zeupater and others.
I don’t really need upstairs to be as warm as down stairs so what would you think about having the PAC system for upstairs and then add one of these toshiba units for down stairs?
Or would you suggest to bin the PAC system and just get good PV install and 2xtoshiba units and have one for both floors. Martin

Hi mg, afraid I've no experience of a pac system but, according to my installer, suspect the purchase and installation cost may be equal to two of the other units suggested and maybe not be quite as efficient. Either way I would suggest you fit as many solar panels as possible(even with the minor complication of DNO permission) as opposed to the std 16 offered by many installers.

Your rooms are large, do you know if the outer walls are solid or cavity wall and if so are they insulated?
From our experience(with insulated cavity walls) our lounge is approx 28 x 13ft which the one unit is heating adequately with some warming drifting into the hall. Our second unit is mounted in a lobby with doors to bathroom opposite, two bedrooms and the hall. For sure it is unlikely to heat them all at once but sufficient to keep the bathroom toastie and the bedroom comfortable. The second bedroom is spare so rarely needs heating, yet can be warmed if required.
If you've a landing or similar from which all/most doors open to then it might offer the best place to site a second unit. If you can place it directly opposite the bathroom then it maybe the best option for keeping it warmer than the other rooms without mounting it in the bathroom itself.
Not sure if you've an existing CH system you are planning to replace. If so, finding out the boiler output would give a useful guide as to the size/number of ASHP's required if you take that route!
Hope this helps.

Coastalwatch

Coastalwatch wrote: »

We've promptly come to the conclusion that life's too short to wait and decided to go ahead with a second unit just as soon as can be arranged.
Rather than siting it in our bedroom, as originally thought, our installer suggested the small lobby positioned centrally in the bungalow.
On reflection it's a much better option, not that we spend time in there, but the doors to four rooms open from it. In particular the north facing bathroom which the unit would point directly at and so make nice and toastie. To one side are the two bedrooms and opposite those is the hall door. So, as suggested by the initiator of this thread, it's then merely a case of opening or closing doors to supply heat, or not, to adjoining rooms as deemed necessary. Admittedly that leaves the kitchen and a small ensuite which are unlikely to benefit from heat of either ASHP unit but otherwise we should have the option of heating the entire property by renewable energy. I don't believe we shall do away entirely with burning gas, we also have a gas hob, but should be able to significantly reduce our dependence upon it.

Installation completed yesterday. Evening testing with three doors open saw the bathroom toastie in about ten minutes. Bedroom temp increased from 18 to 19 degrees in the one hour the unit was running. Admittedly outside air temps were 7 degrees, so not as cold as it will become. Encouraging all the same. I've set the timer for a weeks duration of one hour in the morning, 7 - 8am and one in the evening 9.30 - 10.30pm. We'll heat the lounge as and when required.

I've turned the GCH radiators off in the lounge, hall, lobby and bathroom. Also turned the thermostat down to 15 C intending that it cuts in only if/when temperatures reach that low in the otherwise unheated rooms, namely kitchen, 2nd bed & ensuite.

I wonder how long it will be before the GCH cuts in or I have to turn the thermostat up a notch or two!
For the time being we shall only be using gas for supplementary heating and hot water. So maybe a reduction of 75% or so!

We're by no means FF free but working towards it, as surely we must all do in the fullness of time. Finances permitting of course.

mgbond

Thanks Coastalwatch

I intend to check if the walls are cavity (built in 1980). Due to an extension, there are no outside wall to feed the upstairs hall. This is why I would like an outside unit that then pipes the heat to each room via the loft. If not then it would have to feed from the bathroom to the rest of upstairs. Can these heat pumps have more than one feed into the house. The extension sticks out 1.5m beyond main house so if Heatpump was mounted there then it would be good to have two feed, 1 to extention (kitchen) and 2. Lounge?

Exiled_Tyke

mgbond wrote: »

Thanks Coastalwatch

I intend to check if the walls are cavity (built in 1980). Due to an extension, there are no outside wall to feed the upstairs hall. This is why I would like an outside unit that then pipes the heat to each room via the loft. If not then it would have to feed from the bathroom to the rest of upstairs. Can these heat pumps have more than one feed into the house. The extension sticks out 1.5m beyond main house so if Heatpump was mounted there then it would be good to have two feed, 1 to extention (kitchen) and 2. Lounge?

Is this what you mean?

https://www.appliancesdirect.co.uk/p/eiq-3ms9k9k9k/electriq-eiq3ms9k9k9k-air-conditioner#/maindesc

Coastalwatch

mgbond wrote: »

Thanks Coastalwatch

I intend to check if the walls are cavity (built in 1980). Due to an extension, there are no outside wall to feed the upstairs hall. This is why I would like an outside unit that then pipes the heat to each room via the loft. If not then it would have to feed from the bathroom to the rest of upstairs. Can these heat pumps have more than one feed into the house. The extension sticks out 1.5m beyond main house so if Heatpump was mounted there then it would be good to have two feed, 1 to extention (kitchen) and 2. Lounge?

If built in 1980 then external walls should have a 50mm cavity, but may not be cavity filled. It's worth having done if not. To check have a look at the brickwork outside to see if injection holes have been made and then filled. They are usually about a metre apart and at joints of horizontal and vertical mortar.

It is possible to have more than one internal unit, or multi split system as indicated by Exiled Tyke. Our external units are mounted on the wall of the gable end, above the garage then fed straight into the loft and from there down into lounge and lobby. As a vertical drop is involved each required a pump to return condensation collected, during cooling ops, to the outside world. Normal practise but just needs costing in.
I've been advised that single units are more efficient than a multi split system but have not sort to do a cost comparison. The system indicated by ET seems a good price. No doubt others are available!

ukbfg

This is an interesting thread. We already have solar panels and are considering either ASHP/GSHP. Presumably it would also work as well with a GSHP?

I quite like the idea of the solar panels actually producing 3 or 4 time their output in heat. Sounds a very efficient way of going about things!

What's the factors that vary between Air or Ground source? We have a decent plot of land with plenty of space for burying stuff if needed.

I still have lots of reading up to do. Any general thoughts or advice please?

Coastalwatch

Hi ukbfg and welcome(others might say to the Madhouse). But it's very supportive and been a tremendous help to me.
Having installed two Air to Air SHP's the choice of these was based on my limited understanding of matters given that these are more efficient than GSHP's at a ratio of approx 2 to 1. Equally the costs to purchase and install are less, I've heard figures in the region of £15k for supply and installation of the latter. But don't let that put you off doing your own investigation upon it.

My experiences of the ASHP's are well documented earlier in the thread so reading it through in it's entirety will serve as a basis for you to make an informed decision.
I'm sure others will add their further thoughts and helpful advice.

ukbfg

Coastalwatch wrote: »

Hi ukbfg and welcome(others might say to the Madhouse). But it's very supportive and been a tremendous help to me.
Having installed two Air to Air SHP's the choice of these was based on my limited understanding of matters given that these are more efficient than GSHP's at a ratio of approx 2 to 1. Equally the costs to purchase and install are less, I've heard figures in the region of £15k for supply and installation of the latter. But don't let that put you off doing your own investigation upon it.

My experiences of the ASHP's are well documented earlier in the thread so reading it through in it's entirety will serve as a basis for you to make an informed decision.
I'm sure others will add their further thoughts and helpful advice.

Thanks. I will make my way through the whole thread then.

I think I read that GSHP also work better with underfloor heating and isn't a s straight swap for a standard boiler. A lot more reading required I think!

I guess the most obvious difference that didn't actually occur to me until now, is that one's air and one's water.

Coastalwatch

ukbfg wrote: »

I guess the most obvious difference that didn't actually occur to me until now, is that one's air and one's water.

I think that's correct although there shouldn't be a reason why it cannot replace the boiler in a conventional central heating arrangement. Other than it may cost rather a lot!