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View Full Version : ashp as primary heating source ?







Essex1968
04-11-2008, 10:49 PM
Hi.

I'm hoping someone here may be able to give me a little advice.

I am looking to install an air source heat pump system to directly heat my house with the warm air.
(and also benefit from cooling in the summertime )
Is this a feasible option ?
I have been quoted on some Daikin units as follows

FDXS35E to be located in the 4 rooms upstairs
FDXS50C to be located in the 4 rooms downstairs
3MXS68G X2 and 4MXS80E x2to be located outside

The total floor space of these rooms is approx 200m2

My main question is will I need to provide additional heating in the winter. It is in a property that will comply with all building regs ( regarding insulation )

Any advice would be appreciated.

Karl Hofmann
04-11-2008, 10:57 PM
Provided that you size your units carefully, a little larger than required then I see few problems using air source as your primary source of heating.

Any thoughts on heating your water? there are some pretty good air to water units around these days too

S_Line
11-11-2008, 11:48 AM
spec list looks pretty good, with a total of 4 outside units.

I have big concerns with relying solely on Heat Pumps for Heating, as we all know they freeze up, just when you need the heating the most.

This is why its best to Oversize / Use more than one outside unit.

I have heatpumps in my house ( Daikin cassette, a MHI mult with 4 wall units, and two MHI single splits. I do also have Gas underfloor heating, so not a real test of the heatpumps.

I know many plumbers that are cautious about Air Source heatpumps and the claims they make with regards to Heating the house and hot water.

The MG Pony
12-11-2008, 07:10 PM
As others said, never put all your eggs in one basket.

Electric/wood/gas back up should be equiped, you may never need it but good to have it there! Or at the very least use a ground coupled HP

brunstar
23-11-2008, 09:42 PM
if you are using a few multi systems depending on the kw required and how you run the systems as to how much capacity you will get out of them.
i would, in domestic always overlap the units, so have a bed or two on a unit and living on the same one if you have more than one multi, then you can install more kw than the outdoor unit is specified to do as you may only use one area at any one time, then you can proiritise one indoor unit to work as full capacity in the unlikely event you have them all on.
up to you.

HVAC Master
24-11-2008, 02:02 PM
Hi.

I'm hoping someone here may be able to give me a little advice.

I am looking to install an air source heat pump system to directly heat my house with the warm air.
(and also benefit from cooling in the summertime )
Is this a feasible option ?
I have been quoted on some Daikin units as follows

FDXS35E to be located in the 4 rooms upstairs
FDXS50C to be located in the 4 rooms downstairs
3MXS68G X2 and 4MXS80E x2to be located outside

The total floor space of these rooms is approx 200m2

My main question is will I need to provide additional heating in the winter. It is in a property that will comply with all building regs ( regarding insulation )

Any advice would be appreciated.
Hi,
You are advised correctly. Heat pump can provide you heating as well as cooling in the summer. This is not necessarily Daikin unit but other manufacturers also provide this type of air-conditioning units. It is just a matter of estimating what capacity shall be needed although the heating is more than cooling which s provided by this type of units which are also called reversible units.

daddymac
24-11-2008, 03:44 PM
I have 3 seperate ASHP's in the 3 bedrooms of my house. This is in addition to gas central heating. The original reason for the install was to be cool in the summer, but the heating function is fantastic once it's running. If you think about it, it is a safe form of heating as nothing gets particularly hot... unlike an electric or gas heater, this there is much reduced fire risk! Reassuring when you're falling asleep feeding the baby at 4am!!
The only thing I'd say is that the sizing is very much dependant on how well insulated your house is! If its a solid walled detached house, then going up a size is a good idea. The manufatureres claim you get around 3kw of heat out for every 1kw in! This is only in certain conditions... when it's really cold, they aren't quite as effective, but still impressive enough!

HTH! DM

back2space
25-11-2008, 09:18 AM
My lg multi split heat pump is in operation all the time. We have central heating in our house that is converted into flats but we have no control over the times of the central heating so i program the heat pump to come on after the central heating to keep the place warm, it copes better than the central heating which are massive double radiators because i slightly oversized the units.

mwbostock
02-08-2010, 05:32 PM
Hi i have installed a daikin multi room unit 3mxs68g into a 3 bedroom house with 2x ftxs20g's and 1x ftxs25g. the 2 ftxs20g's work fine on there own but when i have the ftxs25g on as well it will only work if one of the ftxs20g are on the lowest settings 18cent. if i turn the ftxs20g up 20 cent then the ftxs25g gets warmer. and if i try to run the ftxs25g on its own then it will only blow out warm air. can any one help me please.
Thanks