Bit off topic. Sorry
Heat pump grants worth £5,000 to kickstart low carbon heating
Heat pump grants worth £5,000 to kickstart low carbon heating
Don’t you need a big garden for these to be effective ?
@AirCon.
"In moving water" sourced heat pumps are the best near constant on temperature to the collector (evaporator) with only a tiny reduction in water off temperature. So for those of you with a river... yer laughing. .. however Environment Agency approval is required.
Next is ground sourced heat pumps.
These require several 100's of feet of slinky to be buried at a grave depth in a sunny garden ... a couple of tennis courts should do for say 25kW.
Next you need a spare garage space for the equipment. Saline is pumped around the slinky to collect heat, this is then cascaded to heating temperatures using refrigeration. A further heat exchange process warms the sanitary and heating water. Projects start at £25k upwards. Recent 5 bed new barn conversion, no change from £50k.
Air sourced heat pumps is what 99.9% of us will get.
Visually these look like the outdoor Box of an air conditioning system.
Typically double vertical fan producing around 10-14kW of hot water at 35°C.
Water in and water out on 1" 1/4 pipes, flow controlled by the box and ambient conditions.
These cost around £5-7k plus installation.
98% of households will require major reworks of the plumbing and heating systems to make them work comfortably.
Even those who currently have underfloor heating by water should have them replaced.
The most efficient temperature for a condensing gas boiler is 55°C water flow out... heating calculations based on loads and losses means the pipes are widely spaced.
Air sourced heated water is most efficient at 35°C.... hence the pipes need to be closer together to produce the same temperature rise in the room.
Immersion heaters are used to bring the water temperature up for sanitary use (55°C).
IMHO the most cost effective solution is to fit bog standard AC (air to air)... good multiple head system 5 rooms installed, say £8k.
Heats (and cools) a three bed semi. For the 6 weeks of the year when the efficiency drops use your gas heating.
Use gas to heat water all the year.
Most important is to have good insulation, floors, walls, doors, windows (shut) and roof/loft spaces.
For example my wife cranks the kItchen radiators to 25°C, last week we externally insulated 90% of the kitchen walls with 2"jablite.
The apex ceiling has space blanket stapled to the rafters... it now looks like a spaceship.
Result is she has turned off all the radiators and the only heat is from cooking and losses from the circulating hot water... a toasty 22°C...
It looks shit, but the building is coming down in the spring.
CO2 refigerant based air to water is the way to go.
Widely used in Nordic countries and new commercial projects here.... equipment is currently 5x the cost.
However, 4x heat extraction at -20°C and nearly 8x at 8°C ambient outside temperatures, with flow temperatures up to 80°C with no direct electric heating.
This is what the government should focus on.
Also district heating projects and local electric generation...... more to follow,