Marvin

Not impressed with all the fixings through the roofing felt either. ☹️

If this was my work I would be fixing metal plates on each one. The ones I would personally use:

is the gable end of the building the footpath boundary?

The viewpoint used to decide items is a balance between the outlay cost and the running costs. This system will not be the cheapest way to produce heating and hot water nor the most expensive installation system but a balance related to the existing equipment and personal requirements. BEST ADVICE: Read the manual of the product you are proposing to use BEFORE you buy, especially regarding the installation and check that it will work for you. Choosing the ASHP: The size of the ASHP was determined by the heat loss calculated and the peak heat demand when the outside temperature is -8C. This resulted in the requirement of a small ASHP. We did not want an all singing all dancing system, but one that would combine with the existing central heating radiators/hot water tank and MVHR. An air to water ASHP was chosen to be able to use the existing central heating radiators already installed. The radiators are too small to produce enough heat at the lower running temperature of an ASHP so water coils are being installed in the MVHR system. The other alternative would have been to replace the radiators with larger ones as the existing ones are almost all single panel which could be replaced with double panel to increase the heat output. This option is going to be held in reserve depending on the effectiveness of the water coils in the MVHR ducts. The ASHP was chosen for it minimum working temperature of -20C and the fact that it had an inverter. An inverter heat pump uses a variable speed compressor which modulates its output increasing or decreasing its speed to match exactly the heat demand requirements of the building as the outdoor air temperature changes. This makes for a more efficient output. Because the bungalow is on the edge of an estate we wanted have a low noise unit. The unit installed is listed as 46 and 60db. I think that means 46db when running at lowest and 60db when flat out. (I'm sure someone will tell me). With the distance from walls and other properties this is well within MCS requirements. Because the bungalow suffered from strong solar gain in the summer the choice was made to install an ASHP with cooling. ASHP - planning, MCS: In order to avoid requiring planning permission the decision was taken to install the ASHP under the permitted development rules. The only position where the ASHP unit could be situated within the rules was on the flat roof. Because the flat roof has 200mm of PIR and the ASHP unit is about 88kgs concern has been raised that the vibrating motion may erode the PIR over time. The decision was taken to install and monitor the out come. The positioning gives an open run of air to the unit, but far enough from neighbours to hopefully avoid problems. Its. not perfect because during the summer it is exposed to the full sun. We hope to mitigate this when cooling the building by using the PV energy to run the ASHP. The theory being: Summer=hotter sun=more electricity produced= more power to produce cooling using the ASHP. ASHP pipework: The shorter the pipework between the ASHP and the thermal envelope of the building the more efficient. The greater the pipe insulation the more efficient. The shorter the pipework between the ASHP and the hot water tank/ heating system the more efficient, especially to/from the hot water tank as the water temperature is usually higher. ASHP connections: The pipework required is 28mm for this ASHP all the way round through the hot water tank, through the buffer tank and back to the ASHP. We used 25mm thick insulation. Two flexi hoses were used at the ASHP end with two 28mm isolating valves. The power cable used was 6mm twin and earth. The cable size is related to the possible voltage loss not just the power required! Apparently the ASHP is sensitive to voltage loss. To be honest I think 4mm could have been used but there was a roll of 6mm purchased for the PV with enough excess, so this was used. A suitable fuse was required which needed to be a MCB or RCBO Type C 20amp with this ASHP. A RCBO was installed. The control of the ASHP is via a Carel LCD "user-friendly" interface Controller and various electrical links. (More later as this develops...) The 3 port valve is a 3 Port Diverter Valve not a 3 port mid-position valve. The mid-position would allow water from the ASHP to go both to hot water and heating at the same time. However the temperature of the water flowing to heat the hot water tank is expected to be different to the temperature of the water flowing to the heating/cooling. The water side of the system will require antifreeze. so the volume of the water will need to be calculated... Please let me know what else I have forgotten...

Installing coil in ducting Note that the condensation pipe still to be connected.

The coils being prepared for the MVHR ducting

An Excel spread sheet has been used to calculate the heating and cooling. One thing also calculated is that at peak energy the bungalow requires as much for the heating in the winter as for the cooling in the summer! So the hottest part of the hottest day and the coldest part of the coldest night need about the same amount of power! This is mainly because of the solar gain through the windows. The calculations were compared with what has been used for heating and it is reasonable good. The calculated heat requirement is down to -8C although I cannot find records here of colder than -5C. It is assumed that the ASHP will supply all heating and hot water when required. (hopefully mainly hot water heating from excess PV power) There is a back up immersion in the buffer tank but I hope to never use it. The cooling is another thing all together. The ASHP manufacturer informed us that if you run the cooling through the radiators below about 19C this will cause condensation - They were right. When running the ASHP in the summer in cooling mode at 18C the radiators began to get wet because the warm air was being cooled and the cooler air could not hold as much moisture.( the buffer tank also started to do the same and this has to be sorted as well) This is what is know as the dew point! Water coils are now designed to be added to the MVHR ducts to overcome this problem by cooling the air entering the building. The MVHR will be boosted with cooling to the east end of the building, or the west end of the building ( no south windows) when there is strong solar gain. As a trial the ASHP will be left on 24 hrs to see the effects. The temperature of the heating water produced by the ASHP will be turned down to the lowest setting which keeps the desired room temperature. Anything else let me know

Following 1 I try to detail the info so people can check... The bungalow ran on LPG bottled gas for 3 years heating and hot water so I know what was used: I have used the worst 2 years: I am using the conversion rate of one kg of LPG gas giving about 14.091kW hours In 2 years we used about 13277kW of LPG energy for heating and hot water. ( about 10 bottles of 47kg ) If we deduct a modest 2kW for hot water each day ( total 1460kW) that leaves about 11,817 for the 2 years. In summary about 6000kW per year so 60kW per year per square metre of floor was what we were achieving. The target temperature in the house is 21 degrees C generally with 10m2 of rooms at 23C. The MVHR runs at about 6watts an hour or 52kW a year. I have a plug in meter on it. so lets say £20 a year power. It saves masses of heat.

The holistic set I am installing is: ASHP main parts: : Air to water Cool Energy inverTech Air Source Heat Pump CE-iVT9 4.3kW-9.5kW Cool Energy 60L Stainless Buffer Tank CE-B60 MVHR main parts: Domus HRX2-D Heat recovery System with "summer bypass" 125mm and 150mm rigid circular ducting and Domus duct insulation. Electricity Generation main parts: PV Sofar Solar Grid Tied Inverter 6KTLM-G2 16 Longi 320W Mono Solar Panels CT clamp to limit power generation into grid. HOT Water system: 206 litre indirect hot water cylinder. 1kW by 27 inch 240 volt immersion heater Pump to showers Heating system: Panel radiators and two CWH 160-3 VentMatika Circular duct water heaters in the MVHR ducting. Cooling system: Two CWH 160-3 VentMatika Circular duct water heaters in the MVHR ducting. EV charging point: 13 amp plug-in point direct to ring main 13amp plug-in point controlled by PV production via CT clamp. Controls: Dampers to the MVHR. water flow sensors CT clamps

I try to detail the info so people can check... The bungalow ran on LPG bottled gas for 3 years heating and hot water so I know what was used: I have used the worst 2 years: I am using the conversion rate of one kg of LPG gas giving about 14.091kW hours In 2 years we used about 13277kW of LPG energy for heating and hot water. ( about 10 bottles of 47kg ) If we deduct a modest 2kW for hot water each day ( total 1460kW) that leaves about 11,817 for the 2 years. In summary about 6000kW per year so 60kW per year per square metre of floor was what we were achieving. The target temperature in the house is 21 degrees C generally with 10m2 of rooms at 23C. The MVHR runs at about 6watts an hour or 52kW a year. I have a plug in meter on it. so lets say £20 a year power. It saves masses of heat.

Air tightness was followed to a reasonable standard: All external walls sealed with plastic before the electric first fix Plasterboard ceiling to almost floor and then siliconed / masticed to floor. No open fireplaces, cat flaps or tricklevent.

The bungalow has an average of 180mm of PIR under the suspended floor. The cavity walls have an average of 140mm PIR in the walls The loft has an average of 300mm of fluffy. Theflat roof has 200mm PIR. The doors and windows are the latest double glazing.

The bungalow was built in the 1970's and extensively renovated in the last 4 years. It has external block walls and timber suspended floor, timber frame including all internal walls and concrete tiled roof running east/west at a rise of 23 degrees. Having never heard of, or gained knowledge from, buildhub I renovated and extended the bungalow as best as I knew. The garage was converted and has a flat roof. Fortunately the work included insulation, air tightness and a MVHR unit. We ended up with about a 100m2 bungalow.

Confused between zoning and zones, so sorry @Olf I can think of no further reasoning, and you will have to wait for an expert. Perhaps just needing 3 separate runs to rads, ufh and uvc.

Another choice perhaps.. https://coolenergyshop.com/products/cool-energy-60l-stainless-buffer-tank-ce-b60

Is this a help for you: https://www.hse.gov.uk/pubns/indg411.pdf You seem to have responsibilities if this information is correct north of the border. Good luck.

I too have looked at this and we don't have anything like enough land, or money to buy batteries, to make this work. Interestingly our system, over a year, will produce enough power for all our demands, just not at the time when we need it....

I’m starting to think that’s the way forward… can you expand on the suggestion of a more efficient system? As @TonyT suggested any opinion would be related to the thermal resistance and airtightness of the house so details of that a must really.... We live in bungalow with no mains gas, which had night storage heaters, but renovated with better airtightness, insulation, MVHR and an LPG boiler but have recently removed the boiler and have recently installed an air to water ASHP, PV on the way, and an electric car charging point. We have kept the indirect cylinder and are looking to use the hot water immersion when we have excessive PV power, or into the EV.

I don't know lots about UFH, however different areas of a house require different amounts of heat to reach the same temperature so zoning sounds sensible. Extension and original house may have different thermal resistance so different amount of heat required to reach the same temperature. Definetly upstairs will be warmer because the upstairs floor is warm.

+1 This the route I'm taking

Well, the limit to the expansion vessel pressure drop is the volume of the red expansion tank. Another possibility is the pressure relief valve is letting some water out. Good luck.

Definetly before changing anything, now is the time to consider the options. As a guess, a direct hot water tank or a sunamp, is not really that much more spread over a few years. How was the old HW tank heated? Electric?

+1 Concentric if possible seems the best to me....

It's very difficult to jump in when you don't know all the history ... In my humble opinion.... Item 0: if radiators cold at top and hot at bottom means top full of air if radiators cold at bottom and hot at top heat coming out of radiator quicker than the hot water is replacing the cold water. Possibly a pump issue but water flow not travelling fast enough. Item 1: don't know about Zilmets but all in loft? I would insulate the pipes as thick as possible and all other items I could. Item 2: our 215 litre indirect tank can loose the same amount of temp in a day, but we are working on insulating it more. We have it in our bungalow in the utility room. Item 3: the expansion vessel is not leaking otherwise there would be a puddle on the floor. You have a leak or the air in the system is still draining out. Last item: Sorry to hear of the positioning. The further away the better. Good luck Marvin

Surely the three pin round socket for the museum?