Bornagain

As you have experienced, if the radiators are large enough that 38C water can heat the house then a HP is fine, not as good as UFH which in our case is fed with water in the mid twenties. There are many factors that influence the cost of heating, but insulation and air tightness are king.

This story is on the one hand completely true, whilst at the same time pretty misleading. It is cheap to operate a heat pump driving underfloor heating in a well insulated shell and slab, or an air2air pump in a well insulated shell. However, using a heat pump to heat water to 60C for radiators in a poorly insulated or draughty house is a licence to spend a lot of money both on the installation and energy bills. The Guardian either does not understand the difference, or is perhaps just keen to support the current Government drive.

We knocked down and rebuilt an old house in a village, the house was supplied from the water main with a 25mm meter and we ran the pipe from the meter to the house in 32mm. All our neighbours complain of low water pressure and low flow. Our water pressure and flow is fine, easily enough for two showers to run at the same time. We attribute our lack of problems to the 32mm supply pipe.

No, when running serial strings the Voltage goes up as you assume, the current is the same, and hence the total power goes up, so for example the shed system will have 490V and 5500 Watts, hence a current of about 11 Amps. 11 Amps over 95 meters will require a cable much bigger than 0.8917 mm2. Remember that the cable will go there and back.

We got a guy who knocked down our old house by hand as he wanted the bricks. He did it for nowt, and was easily the mosy dangerous contractor that I have ever seen or heard of. He started the work until a few days before Christmas and was finished very early in the new year - he did it then because in his words " the council and the HSE will be on holiday" The knackered bricks (of which there were many) went on the back of a farm trailer to a farmer for his tracks The timber was burned on site. Metal went to the scrapyard. Everything else went to the tip. Cost = £0. Took a couple of weeks.

Hi, We built a 190m2 ICF house with triple glazing, 300mm eps underfloor, 600+mm insulation in loft, MVHR Our house is all electric but we do have a wood burning stove. Our heating and hotwater come from E7, heating by direct imersion a 500L thermal store, wet underfloor heating downstairs. No heating upstairs. Total electricity demand in the last 12 months has been 7200 kWHr. E7 overnight useage = 3800 kWHr, if you assume that the background load for all the usual bits and bobs is 250w, then the energy to provide heating and hot water is around 3100kWHr/year. 1 kWHr of E7 electricity costs around 7.2p, therefore we provide heating and hot water for about £230/yr. If we did it all with an ASHP @ a COP of 4, then this bill would drop to around £60/yr. This means an ASHP would save about £170/yr - and that assumes no breakdowns or maintenance. By the time an ASHP has paid itself back, it is in the scrap bin and you need to buy a new one. Stick to an imersion heater, much cheaper in the short term, long term, and less to go wrong.

c'mon guys, it's not as complicated as you are thinking......

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