View Full Version : Air to air pump or infrared panels in domestic property?

15-10-2013, 02:16 PM
Hi All,

as winter is coming in rapidly and we are beginning to freeze at a cold house with no heating, final decision needs to be made asap - which system to go for.

Our house is approx. 200sqm and is getting insulated as much as possible but will never be airtight.

We have 2 options:

1. x2 Air to air heat pumps with ducted system - for ground floor and 1st floor.
Looks good and cheap to run but concerns are over noise level, disruptive installation of the ducts, maintenance of ducts and filters, low performance at low temperatures, dry air.

2. Infrared panels.

Also look good and no maintenance and easy to install but main concerns are running costs - currently calculated to be just over 1K for 6 winter months if operating 5h per day, at highest rate of 15p/klw. However, because of the way they work, company selling them says we would actually pay 40% less. I don't count that and only consider worst case scenario because I want warmth in the house 24/7 year round, not only when I am in particular room. I believe it's better for the building also.

Really confused as to which one to go for. Because I haven't yet worked out how much running costs for heat pump would be. But overall, we don't mind paying a bit more for less hassle and overall comfort system. We are waiting for one quote and calculations by a guy who installs ducted systems commercially, but would also like others view on that.

Could anyone advice what running costs for heat pump would be and advice on concerns we have? We had an estimate of 25klw boiler if we went for biomass.

Many thanks!

15-10-2013, 02:32 PM
BTW installer of pumps told me that he recommends Mitsubishi FDUM71VF/FDC71VNX for first floor
and FDUM125VF/FDC125VNX for the ground floor.

16-10-2013, 02:18 AM
Coming from a country where air distribution is king, DON"T use a ducted system. Lowest common denominator heating.

With an ASHP stick with floor heat or rads, oversized and with a buffer tank

16-10-2013, 04:17 AM
What about a single unit with zoning dampers? For the cost of two ordinary units, you might be able to get a really good unit large enough for both floors.

You might also want to look into storage heaters if you have a variable rate.

16-10-2013, 10:59 PM
Coming from a country where air distribution is king, DON"T use a ducted system. Lowest common denominator heating.

With an ASHP stick with floor heat or rads, oversized and with a buffer tank

hi, I have read about these systems in US and Canada but so far I got impression that it is not working well because usually it is badly installed and old. Do you think new properly installed system would still end up being inefficient..? I imagine it to work just like air conditioning does and my installed says it can reach up to 50C heat..

20-10-2013, 02:37 AM
I think you will be fine with a ducted system personally. Mitsubishi are very good units and work well at very low outdoor temps. My advice to you if you are using it for heating is buy the largest units you can afford (capacity) then you can run them in low fan speed which makes it quieter. Air Con units outputs are sized for capacity with the fan running in full speed. When you run it at lower speeds you get less output and less duty. So buying a larger capacity unit than you need means at the lower fan speeds you are probably close to the heating requirements of the house and then when its really cold you can use the higher fan speeds and capacity to boost the system.

Hope that helps :)

20-10-2013, 07:36 AM
Infrared panels are heating you by direct irradiation. Same as sun on chilly day in mountains. Surrounding walls, and even air, is not much heated. That is OK for some other usage than living quarters. Like church or big store.

If your house is going to be properly insulated, by todays standards, heat loss should not exceed 50W per square meter of house living area.
Therefore, in that case you will need 10kW of heat power to heat your house. Considering that, best comfort and lowest running cost you will get with hydronic floor heating.

If you wish also to cool that house, than it is better to use fan-coil system or ducted system.
Duct system, if properly designed, and regularly maintained, is comfortable, quiet and without draft.
Duct system air off temperature should be above 45C to avoid cold breeze sensation and speed of air in any point in contact with human below 0,5m/s.
Also, it preferable, to avoid excessive air speeds and uniform hot air distribution to design ducts that supply air in heating operation comes from near floor location. That is design goal of good duct system.