SteamyTea

Usually the system has a built in display that can show it. They are sometimes a bit misleading though. You can calculate it yourself, but you really need some monitoring equipment. This would usually be data loggers on the flow and return pipes to log the temperature, a flow sensor to measure the mass of fluid pumped around and an electrical logger to measure the energy input. Then the arithmetic starts. Calculate the output. Specific heat capacity [SHC] of fluid, 4 is close enough for this [kJ.kg-1.K-1] Flow rate [kg.h-1] Temperature Delta between flow and return in kelvin [ΔT] This will give you the kilojoules over the time period measured [kJ]. You can convert kilojoules to kilowatt.hour by multiplying by 0.0002778. It is usual to place a subscript to distinguish the type of energy delivered, in this case a t for thermal is used. kJ.kg-1.K-1 x kg.h-1 x ΔT x 0.0002778 = kWht Electrical logging is usually calculated in mean power [W] or total energy [Wh]. Care must be taken here as they are not the same thing. Energy is power multiplied by time. Energy is usually purchased by the kilowatt.hour so divide by 1000. Again a subscript e is used to show that it is electrical energy. (W x h) / 1000 = kWhe The coefficient of performance [CoP] is the ratio of the output to the input energies. CoP = kWht / kWhe

https://www.amazon.co.uk/Crunch-Ode-Crisps-Natalie-Whittle/dp/0571384102

Yes it does. If you were loosing nearly 24 kWh a day, the heating bill would be horrible. Half time on the play ATM.

Well I made it. Parked about 200m from the Newlyn tide height gauge. So nearly all of you are higher than me at the moment.

I am going to see a play, can't even remember what it is called. Been a very busy week at work with Christmas parties (85 people today, plus the walk ins), so unless I can park within 100m if the place, I will not bother to go, the local Am Dram gave my tenner anyway.

CO2 has a density of 1.98 kg.m3, nitrogen 1.25 kg.m3, oxygen 1.33 kg.m3, so while it is more dense, normal air movement will stop it settling. This is not the same as changing the concentration from 420 ppm to say 30,000 ppm, which will cause problems after 10 minutes. Assuming no fault with the wood burner, the diesel motor and any combusted gas from cooking, CO2 in a narrow boat should not be an issue, they don't have bilges like an ocean liner or a sail boat. They are more like a floating cake tin. But all wood burners are killers, so some precaution needs to be added in.

I am not sure if that is right. See my comment above. I think the problem is that the air test, is a pressure test, so not the same as an ambient pressure test, but if, unpressured, a house replaced half the air every hour, then MVHR adds to the losses. There are probably many old houses that loose that much air to 'natural' ventilation.

There is the PSI number for linear metre of exposed wall, plus the air film numbers for the wall area. Off the top of my head I don't know them, but think there is something in the Building Regs about it. MVHR is additional loss to normal ventilation losses. Think of it as a bathroom with the window open (normal ventilation losses) then turn on the extractor fan, it does not make the window close. So even with heat recovery, it still increases the overall losses. Why it is vitally important to get the airtightness detail right. I am out now, but to calculate the air losses at 0.5 ACH, you multiply the volume by the air density, 1.25 kg.m-3, then multiply by the ACH, that will give you about 115 kg of air, then multiply by the specific heat capacity if air, 1 kJ.kg-1.K-1 and finally by the ∆T, should bring you to about 3 MJ.h-1. That is around 850 W, which seems high, so I may have made a mistake somewhere (no pencil and paper to write the numbers down).

I didn't look at the walls this morning, so here is my take on it. Total wall area is 20.5 [m] x 2.3 [m] = 47.15 m2 Minus the window area of 32.9 [m2] gives 14.25 [m2] Wall U-Value is 0.15 [W.m-2.K-1] Power loss though wall is 99W 0.15 [W.m-2.K-1] x 14.25 [m2] = 2.1 [W.K-1] 99 [W] / 2.1 [W.K-1] = 47 [ΔT] Something is wrong. Is it really only 14.25 m2 of wall?

I would like to, but for a change, I am going out tonight, very rare occurrence for me that is. A quick look at them and the seems to be MCBs (mini circuit breakers which are simple over current devices, or modern fuse wire), with RCDs (residual current devices) on the incoming supply. @ProDave may be better placed to identify the components. It is always possible that the MCB has gone faulty.

You do understand it. It is the U-Value [W.m-2.K-1 or W/m2.K (not W/m2/K as above)] multiples by the surface area [m2] multiplied by the temperature difference [ΔK]. So with a U-Value of 1 [W.m-2.K-1], a surface area of 32.9 [m2], the unknown ΔK, but a solution of 881 W. 881 [W] / 1 [W.m-2.K-1] x 32.9 [m2] = 26.8 [ΔK] To work out the assumed outside air temperature [OAT] you just subtract the external temperature from the internal temperature [IAT] i.e. 20°C. 20 [°C] - 26.8 [°C] = -6.8 [°C or K]. Now that is the power (the W) not the energy [Wh] losses over a set time period when the OAT is -6.8°C i.e. a cold winter day. To calculate the energy lost, you have to multiply by the time in hours [h] to get to Wh, which is how we purchase energy (we purchase in kWh, so need to divide by 1000). Now we do not have fixed temperature differences, they vary over the year i.e. large in winter, small in spring and autumn, irrelevant in summer (they they can be positive as well, we call that solar gain). Temperature probabilities, based on a typical metrological year [TMY] are used to calculate the amount of time spent at different OATs. Now you may have noticed that I have mixed descriptors for temperature, sometimes I have used celsius [°C] and other time kelvin [K]. This is considered very bad practice but is often used to make it easier to read. There is a reason that it is bad practice and that is if you are adding or subtraction temperatures then the scale name makes no difference as the size of the graduation is the same. But if you are multiplying or dividing, then you must use the kelvin scale or you get odd results. This is very important when working out radiative losses and the efficiency of CoP of heat pumps. To convert celsius to kelvin, you add 273.15. So -6.8°C is 266.35 [K]. (We should really use the joule [J] for energy and not the Wh, but that is another lecture)

I think I have a copy of that somewhere, may be a decade old.

Welcome. I have a bit of experience with boats, my first paying job was at a boat builders, my sister ran a narrow boat scenic trip business for a few years. I have often thought that UFH on a narrow boat is a good idea, but as already mentioned, the temperature difference between the canal water and the floor temperature can be a problem. In reality, there is not much free floor area in a narrow boat, the name is a giveaway. They are really corridors. You could fit an air to air heat pump as that could be easily incorporated with some forced ventilation. The volume is not great. Around 50m3, or 62 kg of air to heat and change every hour or so. A couple of years ago, I made up some internal secondary glazing to cover my double glazing. This has made a huge difference, mainly because I have a lot of glazing compared to wall area (a problem with small buildings). If you can retrofit something, it will help. Acrylic fitted on the outside also stops fishermen breaking your windows. You say you have fitted a thermal store. What sort, size, temperatures and why. Do you use a log burner? What do you do for electrical power? There was a project boat at Birmingham University that was all electric, cheaper BW licences as well. Could have a 'secret' generator on board for when the boat is moored under trees. Where in the country are you based? The canal network is large, even Cornwall has 1.5 miles of canal.

That was being spoken about on the radio this evening. @Pocster is going to be in big trouble.

They can be a bit confusing because of the terminology. There are 'circuit breakers' that are just modern fuses i.e. they disconnect when the current goes to high for the circuit. Then there are RCDs, residual current devices, theses are for safety and disconnect the supply, very quickly, if they sense an imbalance between the current going into a load, and the current coming out. Then there are RCBOs, residual current circuit breakers, which combine the two above. Now we also have AFCIs, arc fault circuit interrupters, these sense any sparking in a circuit i.e. a live wire that has been nibbled by a mouse, touch a neutral wire that has also been nibbled. To makes it more confusing, the above can have different disconnect speeds, usually in milliseconds. This it to allow for high inrush loads (usually an inductive load like a highly loaded motor starting up). Old fashioned wire fuses are a bit more sophisticated than just a thin bit of wire. They are designed, chemically, to allow a bit of over current for a short period of time. But even if the load is below the designed capacity i.e. 5 amps, they will still blow given enough time. The reason I am still on the original fuses is because my loads are very small. Take my lighting circuit, this has gone from a total of 5 amps down to 0.1 amps, if I put all my lights on at once. The most likely fuses to go are my cooker/oven and DHW circuit. The DHW amperage has not changed i.e a nominal 3 kW. I do limit the time it runs though, so rather than possibly on for 7 hours, it is on for 1.5 hours a day. So it is not really a case that mechanical fuses are more robust/forgiving, really a case that if designed correctly and used sensibly, they can last decades.

Temperature is not energy, or power. Imagine that you had an equivalent surface area of radiators as an UFH system. Now while that is often not practical, once you account for floor area that is covered in furniture and rugs, which reduce the power the UFH can deliver, you may find that the areas are not so different. We should really be calling radiators, UFH and fan assisted, heat or thermal emitters, they all do the same job.

I still have them, and not blown one in the 2 decades I have been in the house. They are probably in the original 1987 bits of fuse wire.

Can you, safely, rewire at the ceiling rose to bypass the switch, then see if it trips? When electrical testing it is not unusual to disconnect circuits and then bridge (twist the wires together) the circuit so that both sides (+&-) can be tested together, from one place.

We have 'partial differential equations' that have to be solved. Partial solutions to equations is easier. That is internal, or intrinsic energy, it is based on Newtonian Mechanics though.

I worked for a company that made performance air filters for cars. The engineers (they were real ones, not pretend ones) spent months making a new induction system for a Subaru, the day came to test it on the dyno, and it made 1 BHP difference. It looked really neat though. Did the Audi ones for the touring cars, that was fun, carbon fibre retainers and a large surface area, and still fitted under the bonnet.

Don't matter on them, they all have flat batteries, so never start.

I would have thought a technician would be good enough. What’s the difference and how do I tell A MCB is a modern fuse, a RCD is a safety device to stop electucution. Sometimes they are combined. Take a picture and post it up, someone is bound to know.

Stick a 47k one in, always makes me raspberry pi circuits work. May be worth doing an Google image search on the components.

Generally you don't need fine filter material to get most suspended solids out if the air. The filters we used to make worked by slowing the airspeed until the particles literally dropped out due to gravity. There is a method that works the opposite way, speeding up the airflow and allowing 'lighter' air to be diverted, with the particles carrying on in a straight line into a catchment container. How some vacuum cleaners work and how military aviation air filters keep the sand and salt out of the reciprocating engines.

Have you got a picture of it, from the inside. It may be a cheap, off the shelf, temperature sensor.