AC on old warm air ducts?

[Phil473]

This is more of an idea at this point.

I had a warm air system in this house when I bought it, complete with air ducts. I've since replaced the system with a boiler/rads, and kept the air ducts for a little bit of ventilation.

Would be it be possible to simply fit an AC unit onto these ducts? The old warm air system was in a cupboard under the stairs, there's ample room in the cupboard for an AC unit, and the external wall is not too far off from there.

Also, would solar panels help with running costs?

I'm happy to plod on with an air cooler and fans for now, and due to shade from trees and concrete floors its actually quite bearable downstairs. But as one gets older these comforts would be pleasant and it would be fair to assume that the cost of AC will go up in years. So may be worth doing now.

 

[jj4091]

Don't think the cost of installing solar panels would be justifiable for that application. But you shouldn't have any problem with the ducting

 

[Madrab]

Guess it would all be down to capacity, volumes and fan output I would guess and whether the output of the AC unit could deliver through ducting like that over distance to numerous places. Some of those whole house HVAC units are pretty big.

 

[Razor900]

I would imagine that you will get condensation on the ductwork that will cause damp issues and rot the ducting out.

It might be insulated but it definitely won't have a vapour barrier

 

[Phil473]

I would imagine that you will get condensation on the ductwork that will cause damp issues and rot the ducting out.

It might be insulated but it definitely won't have a vapour barrier

That's a valid point. Definitely wouldn't want the condensation. So perhaps the existing ductwork, would have to be accessed under the floorboards to have some sort of barrier installed.

Not necessarily going to be much cheaper.

We're currently having 3 weeks of the year where AC would make a significant difference, looking at future MET predictions AC is going to be necessary for living at some point in the next couple of decades.

Ideally, it would be good to prepare for that now. Power cuts may become a thing also, so that's why I was considering solar cells. Already this year, the local area had a couple of short power cuts during a heat wave.

Then of course as everyone gets AC installed, the cost will go up. At the same time, we'll then have more experienced engineers which is a vital component. When I went for warm air renewal no one seemed to know anything, which is why I switched to rads.

 

[jj4091]

I would imagine that you will get condensation on the ductwork that will cause damp issues and rot the ducting out.

It might be insulated but it definitely won't have a vapour barrier

I would have thought hot humid air from a central heating boiler more likely to generate condensation in galvanised trunking than the air from an AC unit.

 

[Razor900]

I would have thought hot humid air from a central heating boiler more likely to generate condensation in galvanised trunking than the air from an AC unit.

The moisture from the warm air unit usually comes out of the registers with the airflow.

If you cool.the ducts you will get condensation on the outside of them because of the relative humidity in the air.

Same reason you get condensation on a cold water pipe

 

[ericmark]

I have a simple portable AC, and I have an old cider flagon to collect the condensate, about 1 gallon. It can fill in around 100 minutes, but can also take twice that time, so I set a timer to 90 minutes to turn it off before it over flows. I really did not expect it to produce so much.

As to if one should use solar to power it, to just power the AC, seems to be a bit OTT, but I do have solar panels and battery, and yes they do pay for themselves, but the debate is mainly what size.

Mine pay for themselves mainly due to using off-peak, the problem with off-peak is peak costs more, with 6 kW of panels, a 5 kW inverter and 6.4 kWh of battery the average cost of combined peak and off-peak is always lower than a single rate tariff.

But at say 800 watt, not sure split tariff would pay, and if no split tariff then you're not getting all the benefits, the same with battery or no battery, without the battery you're not getting the full out of the solar. As to at what point solar pays it is hard to say.

It seems there are 101 tariffs, and some which claim to be suited for solar panels, to my mind are not suited at all.

For the first 20 months I was not being paid for export, and I was trying to control how much I charged the batteries, so there was room for solar, but it did not run out prematurely, and this was near impossible.

I was with British Gas, and I felt I was banging my head against a brick wall trying to get payment for export, moving to Octopus and within a fortnight all sorted, seems I needed a second MPAN number.

I think these may work never used them, but I would assume once battery fully discharged it will auto turn off.