All Activity

You are correct but if you read the post carefully you'll see I said half hour block (the standard time slice for the grid). If your export limit is 3.6kwh and you export any more than 1.8kwh (eg 2.5kwh) in a half hour block you have breached your export limit. The half hour time slice means it is much harder to hide any over export with any inevitable lower export periods eg clouds going over sun for 10 minutes and the system is already working at that resolution. If you do this for every half hour slice you can discourage over exporting because there will be no financial benefit and you might get a visit from the DNO.

Have a look at Requirement G3 - they've even got you needing to provide hot water despite always washing in cold! G3. (1) There must be a suitable installation for the provision of heated wholesome water or heated softened wholesome water to: (a) any washbasin or bidet provided in or adjacent to a room containing a sanitary convenience; (b) any washbasin, bidet, fixed bath and shower in a bathroom; and (c) any sink provided in any area where food is prepared. Whatever next!

Isn't the key problem for any "combi" heat pump going to be defrost and oversizing? For a combi type water flow you need 25kw or so output. With a gas boiler, that's trivial and can be modulated down to 3 or 4kw for heating. Getting a continuous 25kw from a HP means you need more than 25kw to allow for defrost. Such a HP would be large, expensive and struggle to modulated down. Anyrhing else is just a variant of a thermal store or unvented cylinder.

Adding a cold mains accumulator will make a huge difference, for stabilising what you have. Or…. …this. Having small bore pipework between the stopcock and the UVC control group is very impactful on performance, but so many plumbers ignore this; probably some just don't realise it is of such importance. Adding an accumulator can be quick and simple, if you have space for one, and guarantees results. I’ve fitted loads over the last 20+ years and always had great results. Beefing up the control group from 22 - 28mm won’t do much tbh, and I've had lots of UVC’s on 22mm that will do 2 showers simultaneously, where the property has a very good incoming cold mains, so I also doubt that is worth the investment. As always these things are hard to comment on without being able to see the system and survey it properly.

Midsummer, the PV people, have put £250k into the company. I worked for a small wind turbine manufacturer a long time ago. Part of the investor conditions was that they had a patent on their design. Gave the investor something to sell when it all folded, which it did.

... thanks, this matches the builders preference to spray then touch up. 👍

Yes, but the combination needs to be inventive. Adding, say, a lock to an enclosure isn't ever likely to be inventive given how ubiquitous the principle is.

Yep, spot on. Thanks for the link. I completed an installation last Autumn where the old house had 600mm walls completely uninsulated but had been extended with some new walls insulated. This property is heated absolutely fine and the owner says they've never been as warm and comfortable in the house. There's has a 9kW heat pump with calculated heat loss of 6.9kW and I took out a 32kW combi. Interestingly it did take 2.5months for the fabric to warm up - the weather comp curve was a bit all over the place and then suddenly it just settled down to run smoothly. I have used heat loss data derived from studies by some different organisations like Society for the Protection of Ancient Building etc. and recently BRE published updated tables for the calculation of stone walls etc. which bring down the u-values quite significantly. At the end of the day it is simply about the balance between heat in - heat out and the correct means of distributing it around the building, and if you get that right any old building can have a heat pump and benefit from it.

I thought that the idea of any patent followed the basic creative principle that novelty flows from the particular combination of non novel (existing) ideas. It's the way human creativity works - by combining things we already know in novel ways. All patents are just novel combinations of old ideas.

Once its mist coated it will show the imperfections and cracks easier. I'd do all the filling or caulking after that. I wouldn't be dremelling any cracks to make wider. A wet easi fill mix is pretty fine seems to get in cracks ok.

We were told by a neighbour with some glee during our house-warming party (previous house) that the occupant had died in the main bedroom. Luckily there was no smell by the time we moved in!

This is probably a stupid question, but that doesn't normally stop me so here goes... Plastering is done and it seems pretty good I think, but there are the dings and cracks in the usual places. We will be getting the place spray painted as soon as SWMBO can decide a colour. Would it be sensible to fill in some cracks now before painting, or (as builder suggests) do this after the place is sprayed. Is the raw plaster too absorbant to repair before painting? Most of the cracks are only hairline, this one about 1 mm is the widest. A few dings where trades (and myself) have bashed into the walls. I read somewhere that cracks should be dremmeled wider and then flexible filler used, is that a good idea to treat the few bigger cracks?

I see them and fix them all the time. Like I said above, it's unlikely your multi-bloc, but the supply pipework to the uvc that's the problem.

I am talking total combined output there - that is Hot Flow + Cold Flow. If it is Christmas and I have family staying - say every year for the next 15 years. Then you have 6 adults in the house, maybe 2 or 3 grandchildren. You want to run 2 showers at the same time. Someone is running taps in the kitchen making breakfast, someone just put the washer on, and someone flushes the loo. So if the system can't handle it, someone is getting a bad shower, and you are into shouting round the house about who can use a bathroom or ensuite. At present the highest simultaneous output I am getting is 34 l/m combined hot and cold downstairs - that is 17 l/m each for hot and cold. Hot flow and cold flow are not separate, they all come through one input pipe and combination valve. I am only getting more like 20-24 l/m simultaneous combined on other outlets. I don't think this is unusual, part of the selling point of UVC vs gravity fed is the ability to run two bathrooms etc. My mains supply should be capable of 40 l/m+. Are we really saying there is no-one here that has ever seen flow problems with a domestic system regardless of how it is plumbed.

Sorry, the current distance is 475mm, not 350.

I used this mob.

9 a locking mechanism - not really novel. 10 mesh grilles, been used in industry for years to prevent small fingers and animals away from things they should not touch 29 plenty of people have installed a DHW cylinder in a shed outside 30 a modular enclosure novel - no 34 - 36 Here something someone invented about 11-12 years ago - Unical Gas boiler version ASHP version

The EV pre pressure should really be set up by measuring the dynamic pressure with a good flow through the cold taps, (to give say 15/20LPM) after the PRV valve or attached to a (cold) tap fed from the balanced cold on the valve set, which yours are, the prepressure should then be set to say 0.2bar below this, this keeps the diaphragm from bottoming out in any circumstances and also positions it better inside in the EV, IMO. This is probably what happened when the pressure was reduced. It can result in a slightly higher final pressure after a full reheat but this should not be a problem especially since you have a 22L EV on a 252L UVC, If the precharge pressure was 3bar then, after a full cylinder reheat to 60C, the final pressure will be 3.93bar, if the dynamic pressure is 2bar and the EV prepressure is set to 1.8bar then the final pressure will be 4.48bar, a little higher, but not a problem and just may cure noisy operation. I advice(d) the few people I know with UVCs to size the EV to 10% of the UVC capacity and set the prepressure to 2bar anyway even if the dynamic pressure is 3bar.

I think there are 2 angles as to why patents a generally a joke. 1st is if you're a small player and someone doesn't care about infringement and in particular they're in a different jurisdiction there's very little you can do without a very big legal purse, if that's even enough. 2nd which is more to do with innovations is that they're increasingly being granted for stuff that really doesn't actually fit the proper definition for something worthy of a patent and unfortunately the tech industry seems to be one of the worst sectors for this - especially in the US of A. About 18 years ago I developed a new product and the bar for granting a patent was pretty high - i.e. it had to demonstrate that it was an innovation and that the improvement was not something obvious to others skilled in the same technical field, and of course that it hadn't been previously shared. Now for my part, putting a cylinder in a box together with a heat pump to sit outside is hardly earth shattering in terms of an improvement nobody in the industry could think about. Maybe they've drafted it well enough to obscure this? But, at the end of the day, the commercial reality may be the biggest challenge. They are going to need a serious amount of money. As a comparison, Ideal Heating received 5.2 million from the government plus the company itself invested 6.8 million to upgrade its manufacturing plant for heat pumps in Hull. They've already got the manufacturing resources and know-how and someone I knew years ago who owned a company that designed and installed manufacturing production lines in the automotive sector developed a new product - in his situation volume wasn't high enough for the Chinese to be interested so he had to struggle to find the resources in the UK, again even with his knowledge of the industry - this was back in the 2000s. It's not my intention to come across as negative, but it is a mountain they're climbing. This is the reality that killed my product - the testing and production resources, even though a UK manufacturer had agree to help me with all the prototyping support and sucking up some risk their end.

The international search report says that only claims 9, 10, 29, 31, 34-36 are novel, and concludes that none of those involves an inventive step. From a quick look, I don't even think all of the supposedly novel claims are actually novel. For example, "novel" claim 29 merely defines the step of removing an existing hot water cylinder from a domestic building. That doesn't sound very novel to me.

Maybe you missed reading the patent? 😉

Hi all, I am planning a small DIY infill extension/lean-to style structure at the rear/side of my house and would appreciate advice before I go too far with the design. The area is shown in the attached photos. The proposed build would fill in the existing paved area between the house/kitchen door side and the existing garage/outbuilding area, which is about 2400mm x 2700mm. My current idea is: Concrete foundation/base. 3 courses of engineering brick above ground level with proper DPC. Timber-frame insulated structure or brick qall above. Suspended timber floor with insulation and proper ventilation. The existing kitchen external door would remain in place. The existing garage/outbuilding door would also remain in place and stay lockable. The new area would not be heated. I am not planning to open it into the house or remove the existing external doors. It would be used as a separate unheated utility/storage type space, not habitable accommodation. The neighbour’s wall/structure is currently approximately 350 mm from the garage/outbuilding, and the new structure would keep the same gap. I do not intend to build onto the neighbour’s wall or rely on it structurally. My main question is about the legal/compliance route for mainly the foundation and if that is confirmed, then the structure. Because the proposed foundation would be very close to the neighbour’s wall/structure, I assume the Party Wall Act may be relevant, especially if any excavation goes deeper than the neighbour’s foundations. I want to do this properly and avoid undermining or affecting their wall. Questions: Would this likely be treated as a normal house extension for Building Regulations, even though it is unheated and separated from the house by the existing external door? Is there any realistic way this type of build could be treated as exempt from Building Regulations, or is that unlikely because it is insulated timber-frame rather than a conservatory/porch? For the foundation, what would be the safest and most compliant DIY-friendly approach this close to a neighbouring wall: shallow raft/slab, trench fill, pad foundations, ground screws, or something else? If I use a shallow foundation solution that does not go below the neighbour’s foundation level, would that usually avoid triggering Party Wall excavation notice requirements, or is notice still likely because of the distance? Would Building Control normally want to inspect this type of foundation even if the existing house and garage doors remain in place? Are there any key details I should design in from the beginning: DPC height, DPM connection, suspended floor ventilation, fire resistance near the boundary, drainage, guttering/overhangs, or access gap to the neighbour’s wall? I am happy to keep everything within my boundary and do it properly. I am mainly trying to understand whether this can be designed lawfully under permitted development / exemption rules, or whether I should assume Building Control approval and possibly Party Wall notice will be needed. Any advice from people who have dealt with similar narrow side/rear infill extensions would be much appreciated.

(Not the Russell you asked but…) Find your nearest metal fabricator (most towns have a couple or more). Have an idea of what you want and get them to make exactly what you want, to the colour you want. Two ‘L’ section pieces may work, or one ‘U’ section and one ‘I’ section. The metal fabricator will most likely have some bright ideas as well.

Sound like the patent basically covers having a dwh cylinder of any description in box or shed (enclosure) with gshp would be a contravention of the patent. Which is nonsense. Or containing a buffer vessel in the heat pump enclosure and they exist already, would contravene the patent. Good luck to the company, but the patent is a little limited.

Our last house was 1830 build, solid stone, very similar to the the linked house, we were NE Scottish town not rural, ours 3 storey build similar size, a lot of big single glazed windows, if I lived there now, knowing what I know now, would have zero issues installing a heat pump. Would get a better CoP there, than I do here, as we used to heat nearly all year, if fact the heating was never actually switched off (available 365 days a year). We had a similar sized boiler and it was run at a reasonably low temp and on 24/7 with very little setbacks, the boiler just ticked on and off as needed.