SteamyTea

It is an acrylic. PLASTIC & RESIN ASSOCIATIONS WPC EPDA MAPP ARPM BACK PLASTIC INDEX Polymethacrylates Methacrylic Adhesives Methacrylate Monomers COMPANIES ACRYLIC PRODUCTS ENGINEERING RESINS RESIN DISTRIBUTORS ADHESIVES & TAPES PAINTS & COATINGS POLYMETHACRYLATES (PMMA, PLEXIGLAS) PROPERTIES AND APPLICATIONS Polymethyl methacrylate (PMMA), also known as acrylic or plexiglas, is a high volume amorphous, transparent and colorless commodity thermoplastic that can be easily processed and converted into many finished and semi-finished products. Most commercial grades of PMMA are polymerized by free radical polymerization, yielding atactic polymers whereas anionic polymerization yields syndiotactic or isotactic polymers. Most commercial grades of PMMA, however, are atactic with a glass transition temperature of 398 K (125 °C). Commercial PMMA is often copolymerized with comonomers other than methyl methacrylate. The Tg of these products can vary, ranging broadly from approximately 360 K to 430 K (87 to 157 °C). PMMA is known for its stiffness, hardness and excellent weatherability. Unmodified PMMA, however, is rather brittle and has low impact strength and fatigue resistance. To increase its toughness, it is often modified with core-shell rubber or other impact modifers. These resins offer seven to 10 times the impact resistance of standard PMMA while maintaining high transparency.1 Because of its high transparency (92% transmission) PMMA can be used as a lightweight and shatter-resistant replacement for regular glass. It has sufficient impact resistance to be machined and is often an economical alternative to polycarbonate (PC) when very high toughness and impact strength is not required. It comes in a variety of forms such as sheets, rods, and tubes, and is used for signs, optical fibers, architectural structures, tail lights for cars, bathtubs and sanitary fixtures, to name only a few applications. Many other methacrylic monomers are commercially available. They are either copolymerized with methyl methacrylate to improve its properties or are added to many other resin systems to make a wide range of polymer-based products like binders in paints, coatings, toners, inks, and water-soluble polymers.

That is quite a bit of power to pump the water around with. Does it cycle a lot? One would not fit a 3kW water pump.

What sort of power heater is used in this sort of installation. I would have thought 3 kW would be too large.

I would be worried using polymethyl methacrylate if there is steel work in contact with it. We used to cast stuff in it, we avoided anything metal. Though having said that, printed beer bottle tops did not give a problem. Easy way is to test a small sample first, then rapid age it by thermally cycling in an oven.

@Radian Did I read earlier that you have a vented system, the same as I do? I have noticed that in the summer my DHW energy usage drops considerably, my F&E tank is in the loft, so not surprising. Now I know this may not be approved of, but if that tank was warmed to say 25-30°C (an insulated metal one is probably best) with a relatively low power heater (fish tank one maybe) run off the PV, then imported energy may be reduced. I don't think there is a huge health risk as there will be a few billion water tanks in the world that a constantly at that sort of temperature and we don't hear much about it.

Do a sight search as there is quite a long thread on it. Can't remember who started it. Google site search is usually better than the forum search facility.

Welcome. Not living in the real Cornwall then. You got mining ancestry?

Muck, not rug.

So MrTWales, like SteamyTea is all wrong. Set up autocorrect/autocomplete.

Really

Wind chill, in part, is caused by evaporation taking a disproportionate amount of energy from a material. Why a wet bulb is used. I would have thought that as long as the concrete is covered over to stop excessive evapotranspiration, it would not make much difference. Covering over may help trap solar radiation, which may help or hinder. As I am sure @saveasteading has mentioned in the past, the concrete people generally know their business, the builders often don't know concrete. In the aviation composite industry it is normal to embed thermocouples into the moulding during manufacturing. These are then monitored to make sure correct curing happens. I know a foundation is not quite as safety critical, but I am surprised this is not done on large pours. Or maybe it is.

If you are worried about it, so will the person you try to sell it to. Maybe best to walk away now.

'.lb2.mph2 is energy in imperial.

Was it Charles Bukowski's quip that got rewritten to; "Every family needs a lawyer, a doctor and a plumber in it"

I found that was the worse. You know it is coming and there is sweet FA you can do to stop it.

Could have been worse, or better. Operation Plumbbob, at least it has a plumbing term in it. In 1956, Dr Robert Brownlee, from Los Alamos National Laboratory in New Mexico, was asked to examine whether nuclear detonations could be conducted underground. The first subterranean test was the nuclear device known as Pascal A, which was lowered down a 500 ft (150 m) borehole. However, the detonated yield turned out to be 50,000 times greater than anticipated, creating a jet of fire that shot hundreds of feet into the sky.[8] During the Pascal-B nuclear test,[8] of August 1957,[9][8] a 900-kilogram (2,000 lb) steel plate cap (a piece of armor plate) was welded over the borehole to contain the nuclear blast even though Brownlee predicted it would not work.[8] When Pascal-B was detonated, the blast went straight up the test shaft, launching the cap into the atmosphere at a speed of more than 66 km/s (41 mi/s; 240,000 km/h; 150,000 mph). The plate was never found.[10] Scientists believe compression heating caused the cap to vaporize as it sped through the atmosphere.[8] A high-speed camera, which took one frame per millisecond, was focused on the borehole because studying the velocity of the plate was deemed scientifically interesting.[8] After the detonation, the plate appeared in only one frame, but this was enough to make an estimation of its speed. Dr. Brownlee joked the best estimate of the cover's speed from the photographic evidence was it was "going like a bat!".[10] Brownlee estimated that the explosion, combined with the specific design of the shaft, could accelerate the plate to approximately six times Earth's escape velocity.[10] In 2015 Dr. Brownlee said, "I have no idea what happened to the cap, but I always assumed that it was probably vaporized before it went into space."[9][failed verification] Later calculations made during 2019 (although the result cannot be confirmed) are strongly in favor of vaporization

Are you back to normal now? Well as normal as any self builder.

It is what I have done. It made a huge difference.

Ask @craig I quite fancy marketing double glazing and replacement windows. I have some bricks, can easily glue some business cards to them.

I shall get the teapot ready.

Welcome. Design the roof to give you the best PV production in winter. Then lots of insulation and airtightness tapes.

Rubber should be alright, does depend on what adhesive is used. A styrene molecule (C8H8) is around 160 nm, so can easily pass though most timber boards. My polycarbonate lenses in my glasses disintegrated after a few days in my factory. Had to go back to glass lenses.

Not if the area is being coated with glass mat and polyester resin. Just the styrene fumes can cause a significant problem.