Hot air heating or Solar/Storage Heaters for a terraced house

Conte_Vincero

Hello Everyone, I'm looking for heating options for our new 1970s 2 1/2 bed terraced house.

The current central heating is gas fired, ducted hot air. However the unit is ancient and isn't working. I've had a quote to replace it, however this isn't going to be cheap, and I'd prefer to move towards something more environmentally friendly. A heat pump would be nice, but we don't have a lot of outdoor space for the exterior units. 

As a result, I'm eyeing up getting a 2.7 kwH solar installation and some storage heaters. I know there's a mismatch between solar generating electricity in the summer, and us needing it in the winter, but does it work out over a whole year? Or should I just stick with and upgrade the heating system I've got?

FreeBear

A heat pump would be a lot cheaper to run than storage heaters (even with solar panels). An air-to-air HP need not require a large external unit, and you always have the option to wall mount it.

You may find the existing hot air system has a lot of asbestos in it - That would complicate removal & disposal which ever system you end up going for.

danrv

Conte_Vincero said:

Hello Everyone, I'm looking for heatiing options for our new 1970s 2 1/2 bed terraced house.

The current central heating is gas fired, ducted hot air. However the unit is ancient and isn't working. I've had a quote to replace it, however this isn't going to be cheap, and I'd prefer to move towards something more environmentally friendly. A heat pump would be nice, but we don't have a lot of outdoor space for the exterior units. 

As a result, I'm eyeing up getting a 2.7 kwH solar installation and some storage heaters. I know there's a mismatch between solar generating electricity in the summer, and us needing it in the winter, but does it work out over a whole year? Or should I just stick with and upgrade the heating system I've got?

I was in a similar situation a few years ago with electric warm air. Very rare system it appears.
Being an electric only property, I considered using a heat pump with the warm air ducting.
In the end I had multisplit aircon fitted for the ground floor.
2nd option was storage heaters. 

Probably not worth upgrading your current system although gas warm air is quite cheap to run. Gas boiler and radiators is another option but doesn't address the environmentally friendly idea.
Given that the property probably doesn't have Economy 7, a lot of solar generated electric
capacity would be needed for storage heaters. They could amount to 9kW+. 

Any asbestos concerns can be looked into by researching the warm air unit and contacting the manufacturer if still in business.

Conte_Vincero

FreeBear said:

A heat pump would be a lot cheaper to run than storage heaters (even with solar panels). An air-to-air HP need not require a large external unit, and you always have the option to wall mount it.

You may find the existing hot air system has a lot of asbestos in it - That would complicate removal & disposal which ever system you end up going for.

Thanks, I'll get a few quotes for air source heat pumps. Don't think asbestos is a worry but I'll double check. 

Conte_Vincero

danrv said:

Conte_Vincero said:

Hello Everyone, I'm looking for heatiing options for our new 1970s 2 1/2 bed terraced house.

The current central heating is gas fired, ducted hot air. However the unit is ancient and isn't working. I've had a quote to replace it, however this isn't going to be cheap, and I'd prefer to move towards something more environmentally friendly. A heat pump would be nice, but we don't have a lot of outdoor space for the exterior units. 

As a result, I'm eyeing up getting a 2.7 kwH solar installation and some storage heaters. I know there's a mismatch between solar generating electricity in the summer, and us needing it in the winter, but does it work out over a whole year? Or should I just stick with and upgrade the heating system I've got?

I was in a similar situation a few years ago with electric warm air. Very rare system it appears.
Being an electric only property, I considered using a heat pump with the warm air ducting.
In the end I had multisplit aircon fitted for the ground floor.
2nd option was storage heaters. 

Probably not worth upgrading your current system although gas warm air is quite cheap to run. Gas boiler and radiators is another option but doesn't address the environmentally friendly idea.
Given that the property probably doesn't have Economy 7, a lot of solar generated electric
capacity would be needed for storage heaters. They could amount to 9kW+. 

Any asbestos concerns can be looked into by researching the warm air unit and contacting the manufacturer if still in business.

Thanks, I am actually on an economy 7 tariff!

The house is a bit small, and we've just had it redecorated, so I'm thinking pipes and radiators is a bit too much

danrv

Conte_Vincero said:

danrv said:

Conte_Vincero said:

Hello Everyone, I'm looking for heatiing options for our new 1970s 2 1/2 bed terraced house.

The current central heating is gas fired, ducted hot air. However the unit is ancient and isn't working. I've had a quote to replace it, however this isn't going to be cheap, and I'd prefer to move towards something more environmentally friendly. A heat pump would be nice, but we don't have a lot of outdoor space for the exterior units. 

As a result, I'm eyeing up getting a 2.7 kwH solar installation and some storage heaters. I know there's a mismatch between solar generating electricity in the summer, and us needing it in the winter, but does it work out over a whole year? Or should I just stick with and upgrade the heating system I've got?

I was in a similar situation a few years ago with electric warm air. Very rare system it appears.
Being an electric only property, I considered using a heat pump with the warm air ducting.
In the end I had multisplit aircon fitted for the ground floor.
2nd option was storage heaters. 

Probably not worth upgrading your current system although gas warm air is quite cheap to run. Gas boiler and radiators is another option but doesn't address the environmentally friendly idea.
Given that the property probably doesn't have Economy 7, a lot of solar generated electric
capacity would be needed for storage heaters. They could amount to 9kW+. 

Any asbestos concerns can be looked into by researching the warm air unit and contacting the manufacturer if still in business.

Thanks, I am actually on an economy 7 tariff!

Right. That's for hot water.
It may be possible to make use of the cheap rate for heating if the whole property switches over.

ThisIsWeird

Hi CV.
I can't see a 2.7kW PV system contributing much to your CH in 'winter' when it's needed, tho' it should give you all the DHW you need in summer, as well as contributing to your other bills - washing, etc. It's a multi-£k outlay, tho', which will take many years to recoup.
I have a 3.2kW system, pretty much at the ideal south facing angle, and a single 2.4kW Dimplex storage heater supplied via a PV controller that sends any excess generation to it. During summer months, it'll become very hot in a few hours, which is, of course, pointless, so it gets turned off. In 'Autumn' and 'Spring', there are some ideal days where it charges up a very decent amount, and I release this in the evs - it must make a reasonable contribution to that room, tho' I'm not bothered about measuring it.
At the current time of year, tho', it doesn't become even lukewarm on bright sunny days - the sun is just too low, and not out for long enough.
Your warm air unit presumably consists of a centrally-located gas burner and air ducts running to each room, exiting via wall grilles mounted above skirting board height? Wouldn't the simplest solution be to run water pipes through these ducts, to supply (oversized) radiators mounted on the walls to cover the grilles? A compact gas system boiler and DHW tank will hopefully fit in the burner room. (A system boiler could be fitted in an upstairs cupboard or even the loft if that helps. Does the existing flue exit via the roof?)
And relatively simple to later convert to ASHP when designs are improved further.
Or, as you say, modern storage heaters from your E7 could be the cheapest installation, and not be too expensive to run, but I have no idea how that would compare with gas. The 'sums' must be readily available, tho'?

Grenage

To echo the sentiments above, a GSHP is a good option. 

Solar-wise, it's great in summer and middling in winter.  I installed a 3.4kw array for about £1200 last year, and installed a diverter for the hot water tank for about £100.  In summer it can heat the tank and cover our electricity when the sun is out. 

In winter it might make enough to run the house and a dehumidifier on a good day - or next to nothing on a bad.

ThisIsWeird

Grenage said:

To echo the sentiments above, a GSHP is a good option.
Solar-wise, it's great in summer and middling in winter.  I installed a 3.4kw array for about £1200 last year, and installed a diverter for the hot water tank for about £100.  In summer it can heat the tank and cover our electricity when the sun is out.
In winter it might make enough to run the house and a dehumidifier on a good day - or next to nothing on a bad.

DIYed?

Grenage

ThisIsWeird said:

Grenage said:

To echo the sentiments above, a GSHP is a good option.
Solar-wise, it's great in summer and middling in winter.  I installed a 3.4kw array for about £1200 last year, and installed a diverter for the hot water tank for about £100.  In summer it can heat the tank and cover our electricity when the sun is out.
In winter it might make enough to run the house and a dehumidifier on a good day - or next to nothing on a bad.

DIYed?

Yes, I should have added that.

FreeBear

Grenage said:

To echo the sentiments above, a GSHP is a good option.

Ground source heat pumps potentially have a higher SCOP than an air source heat pump. But you need a lot of space for the heat collector (if going for slinkies) or a deep borehole - Either are very expensive to install...

I had looked at GSHP here. Garden isn't really big enough for slinkies, so I would need around 150m of borehole. Very limited access, so it would be impossible to get a decent sized drilling rig in. About the only rig that could get round back is a Dando Terrier, and the manufacturer reckons that 50m would be the absolute limit I could go. Starting price was in the region of £12K and total cost would depend on ground conditions & time to drill each borehole.

In the meantime, Octopus were quoting under £3K for an ASHP.