Marvin

Thank you @SteamyTea. I am sorry that I did not ask the right question but your answer has greatly helped me to understand the basics. (hopefully). So, I understand that when relating your information to my questions you are saying (as its easier than talking about Carnot engines) in a non pedantic sense, the heat (or cooling) produced by an ASHP depends on the existing air temperature, the air passing through the unit and the change of pressure in the compressed liquid. As such if you wish to keep the same output in heat if one of the 3 reduces the heat effect the others have to compensate: When air temperature goes down airflow and/or compressor pressure change would need to increase to produce the same output. When temperature rises airflow and/or compressor pressure change would need to decrease to produce the same output. If I have this right then it leads to what I meant to ask which was actually based on attempting to improve the COP. If we were to keep the same amount of heat production and the air temperature stayed static, which would improve the COP the most, increasing the fan speed and reducing the change of pressure by the compressor, or reducing the fan speed and increasing the change of pressure by the compressor. I assume that both processes use different amounts of energy. If there is no significant difference, what causes users to want to adjust the 2 parameters? Oh well I hope for a simple answer...

Can anyone explain in simple terms what effect adjusting the ASHP compressor and or fan settings will have on the output? Also is the ASHP pump that people have referred to mean the pump circulating the water? The ASHP involved is the Cool Energy inverTech Air Source Heat Pump CE-iVT9 4.3kW-9.5kW. Thanks for your help. M

Hi @F113tch Welcome. I believe that the best energy saving combo is: Insulation, insulation, insulation. Airtightness through design, and construction of build, along with MVHR which gives you fresh air and less loss of the building temperature. Heating with an ASHP, espically if you have PV. ( Here we have a cold bright day and 3kW power at present going towards heating and charging the electric car. We renovated our bungalow which has all the above: 100m2. Below zero last night: 8kWhs to keep the house above 19C. Good luck with your plans. M

There have been lots of discussions about the effectiveness and efficiency of an ASHP and so I am keeping basic records. I have my own electric meter on the supply to the ASHP so I know how much power has been used whether from the mains or the PV. The result so far using the ASHP installed is 123 kWhs have been supplied to the ASHP from Jan 1 to Jan the 21st to heat the building and hot water. As it is difficult to split the power used for hot water (and we have an immersion using the excess PV power on the hot water tank) from the power used for heating if we assume all of this power was used for heating that would equate to an average of roughly 2.6 Watts an hour per m2 of floor over the 20 days. Normal living with 2 people, showers, average 20C inside all day. Last night -2C outside some of the time. Used in the last 24 hours: 12kWh's. Whilst we are happy with the results now being obtained, I would like to point out that the results were completely different when we installed the ASHP, when the very thick lagging was missing and we were using it like a boiler! Good luck with your endeavours. M

Oh yes and covered it with 50 mm of celotex.

This was our bungalow before we renovated it!

A kit of Tracepipe 22mm 15m long is about £160 including fittings each end. certainly cheaper than altering the mains gas pipe, even with labour!

Hi @SuperPav Sadly +1 to temp's suggestions above. ASHP is good if you have great thermal resistance and airtightness because its strength is being able to keep the temperature stable. But if you have heavy thermal loss the ASHP has to work much harder (less efficiently) to raise the temperature. Put as much insulation in the loft as you can. We have about 100m2 bungalow with the combo of an ASHP, MVHR, PV and an EV. This works very well. But we have a timber framed 1970 renovated and greatly insulated building with about 200mm rigid insulation in the floor, 150mm insulation in the walls and 400mm fluffy in the loft, no trickle vents, no cat flap and reasonable airtightness. Good Luck M

Sorry @elrao you caught me when busy. I meant to say best to check all the document (which it looks like you may have already done) Good luck M

Actually, I'm not sure about the other rules...

Between a rock and a hard place....

In my humble opinion... Sometimes these walls are rendered over because of the effort involved in repositioning and pointing around each stone. Its unlikely that render will stop any serious structural problems already there, but it will stop the stones from loosening and falling out, causing a serious problem.

Hi and Welcome @elrao https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/830643/190910_Tech_Guide_for_publishing.pdf Long and boring but look at the pictures and page 10. Sorry to disappoint. Good luck. M

Surely @Adsibobyou will be the site 24 hour security? A sort of Grenfell fire watch team... Oh and plenty temporary battery ? smoke alarms....

+1. Is the screed on concrete or insulation? If on insulation then I wouldn't go near it for days. And how thick is it?

Primary pipework insulation with additional insulation Buffer tank on the right. Gaps for pump and port valves Hot water tank hiding

Hi @Wil Hmm... Leaky buildings are a big problem. Make the building as air tight as possible.... fill every gap, seal round every pipe on the inside and outside of the external wall. Are you fitting mechanical ventilation? How are you supplying air to the wood burner? Of course we had to have a new EPC certificate, as our one was older than 2 years, before we could apply for RHI.... This is a timber framed 1970's bungalow with a timber floor. We have roughly 400mm fluffy in the loft, 150mm Celotex in the walls and 200mm Celotex in the floor. We have a MVHR system for the fresh air. When renovating our bungalow we sealed every join between wall and wall, wall and floor, wall and ceiling and vapour barriered every wall and ceiling. We have no trickle vents in the windows, no cat flap, although we have a letterbox in the front door and only 18m2 of glazing. As the ASHP heating water temperature is already lower than that from a boiler every loss from the ASHP pipe work is a greater percentage. These are some of the other items we have worked on: Made the length of pipe work between the ASHP and hot water tank and buffer tank as short as possible: less than 5 meters in one direction. Insulated the ASHP to tanks pipework to within an inch of its life. 25 - 28 - 25mm walled Climaflex minimum with additional insulation where possible, especially the pipes from the ASHP which are outside the thermal envelope (an additional 100 to 150mm thick fluffy wrapped in EDPM and taped together.) Additionally insulated the buffer tank and hot water tank even though both are within the thermal envelope. Additional insulation to all heating pipework where possible. Finally completed my RHI application today. M

? Fook!

All interesting stuff. This bungalow's temperature rises and falls slowly so the difference between the day and night temperature ( set on a separate digital thermostat to turn the heating circulating pump on) is very little about 2 degrees. Hi @Wil the only thing I have altered is the Weather Compensation Ambient Temperature / System Water Temperature, and the temperature differential and stop, at present as I do not understand what effect changing the compressor frequency or pump speed will have. I believe that turning the settings to a small difference between the outside temperature and the temperature required to heat the building is important, however I have also witnessed the fact that during the early stages of the ASHP start up (cycle) a lot of energy is used to get going in the first few minutes with what seems to be little result. I think this is why it is suggested that the ASHP unit should come on for at least 10 minutes. I am presently fiddling with these parameters to find our best result. As a yard stick: From Sunday at 8 am to Monday at 8 am we used 7.25 kWh. About 5kWh on heating and 2.25 on hot water for 2 people. The average temperature over the whole day taken at 3 hour intervals was about 9C and the floor area is about 100m2, at an average internal temperature of about 20C during a dryish sunny day with about 14mph wind speed So we are achieved about 50Wh per day per m2 floor. However there was cooking being completed which adds to the warmth. M

How are you charging the batteries? Hi @ReedRichardsI think it will work in mode 2 if the CT clip is connected to the cable running to the mains.

This is all about the set up of the Weather Compensation option on my ASHP Yes. I have changed the hot water set point in the Weather Compensation to a constant temperature. Thanks @dpmiller.? Whilst working on this I will adjust the heating temperature and outside temperature set points because once the outside temperature is above about 8C our home requires very little heat (we have run the buffer at 35C when the outside temp is 5C with no problem.) **** For those thinking they can do the same***These changes are in response to the location, BUILDING orientation, construction and use of our property and I would doubt that yours would be exactly the same.

We are trying to achieve this: The minimum hot water tank temperature required to produce enough hot water to meet our daily needs. An increase in the hot water tank temperature as a result of excess PV energy which can reduce the necessity of the ASHP heating the hot water tank the next day. The heating of the hot water tank over 60C after the hot water tank being below this for a consecutive 10 days. To achieve 2. we have installed a SOLiC 200 Model AF2.1 To achieve 3. we have a 10 day delayed relay, which is wired to reset if the hot water tank reaches over 60C, and heats the tank if this is not achieved.( and then resets) To take advantage of cold bright days where excess PV is generated which can heat the hot water tank, we are aiming to keep the tank to our minimum hot water temperature requirement. Also the ASHP is less efficient at producing hot water in the colder weather.

I'm confused with this. I assume your saying build up is joist, flat PIR, firings, boarding and final top coat? If that is correct, it doesn't sound right to me. I'm with @Radian M

Depends also on what is at the top level.... I thought geotextile and planting was about defence against erosion not the possibility of land slip.