Hi.
(sorry for my ignorance of terminology)
Requesting Help:
Before I go ahead and fit an internal ASHP (air to water) to my own home I wanted to know if its possible to purchase an internal ASHP unit separately form the hot water tank usually supplied to fit below. If so where from.
Just to confirm:
I am not interested in obtaining grants - just installing the system I want. I am looking for a small unit of about 4kW input, with some hot water capability and if possible some cool air possibility in the summer, however I am open to alternative suggestions (I have a plan B to use excessive PV to cool the the bungalow in the summer)
The boring technical information for guidance is below. Any further info you need please let me know.
Thanks
Marvin
Existing energy considerations:
Our bungalow has mains electricity.
No mains gas.
Bottled LPG for the gas boiler.
Very small amount of PV (to be increased...)
Whole house MVHR
Good insulation
Good air tightness.
Design considerations that effect the choice of ASHP :
We have a 3 year old existing central heating system run on LPG. The radiators are oversized.(about 50%)
We have a 205 litre hot water tank and the recent addition of my own design solar hot water (still tinkering around the edges but plenty of hot water unsupported for the last 10 days).
We are mildly effected by solar gain (even yesterday) although our windows and glazed doors only total about 18m2 but because of the thermal resistance of the building the heat gets trapped a bit. We want to get rid of the gas boiler and replace with a ASHP and stay warm.
Positioning considerations an external ASHP
After reading manufacturers installation instructions on various models we find there is no where externally that we are prepared to install an external unit for one of the following reasons:
We live nearish to the sea (can hear it if the wind is in the right direction)
The wind can be quite strong and would effect the inlet outlet on a large fan however we can place the tubes from an internal ASHP elsewhere.
Too near the neighbours bedrooms for us to be satisfied that we may cause a noise nuisance.
Too far from the hot water tank to position outside because of the heat loss along the pipes.
Flat roof too exposed to wind and rain.
Heat requirement:
Our results show that the present total LPG energy used to heat our bungalow (100m2 bungalow) and water, is approximately 5800kW per year.
The results, when extrapolated from the temperatures down to -4C (degrees centigrade), also suggest a heating peak of 4kW (before any COP calculations are taken into affect) required for an internal temperature of 23C against an external temperature of -8C.
The calculated energy used to heat the building does not take into account the following: The added solar heat gain through windows, 3382kW per year used for all household electrical equipment most of which generates some heat (not including any EV charging), the now redundant (for a lot of the year) hot water requirement covered by the Solar water panels, and about 200 watts of heat per hour produced by us sitting in the building or about 280 watts per hour if were arguing.
