House heating options

iplogger1

We are at decision time. I'm not sure if the following dilemma
is familiar but here goes....

I can see clearly that when comparing underfloor heating methods
that the heat pump will probably trounce oil in terms of getting
a return on investment. However, the capital cost of the whole
heat pump system installed (even taking grant into consideration)
is high and you have to factor in the additional interest incurred
as part of the mortgage repayments to cover the outlay for that
system. Rational or irrational I also get minor heebejeebies about
the inaccessibility of the ufh pipes, the collector pipes in the garden
and the fact that if Murphys law struck then getting the correct
tradesman out to fix the heat pump might be more time (waiting)
and money because of the specialist status of heat pumps.

My plan B option is to forget about underfloor heating altogether.
We're not that adverse to the look of conventional rads and
the only reason I ever got seduced into looking at underfloor heating
was because heat pumps forced me to narrow my thinking into that
direction. I can see the luxury of UFH in terms of nice gentle uniform
heat with no cold/hot spots in rooms. However, I can also see the
tension between the changeable Irish climate and the slow response
time of the ufh in a block built house. I also see the electricity prices
following the energy demand curve as fossil fuels become more
scarce or more costly to produce,etc. Most convincing payback
arguments I've seen regarding heatpumps have compared UFH with
oil versus UFH with heatpump - I feel standard panel rads would be
less expensive to run with oil than ufh (but could be wrong here).

So here is my dilemma .. How daft is my plan B which is: Standard rads,
high efficiency condensing oil boiler, house zoning/climate control thermostat
as well as TRVs to ensure heat needs for house take outside climate into
account, a solid fuel stove in one of the reception rooms. Spend a
couple of k Euro more on house insulation than we would have if
pumping capital into the perceived luxury of ufh.
Solar heat collectors for DHW needs in the hotter months (my
contribution towards taking a step into greener energy)
Oil Boiler could be swapped out for some (hopefully mature) alternative
fuel 5-8 yrs into the future.

Pragmatic, daft or both ?

any opinions?

bbbaldy

Plan B sounds good to me,its allmost the same as I have planned for my own new home, (after a lot of research), but why not go with a wood pellet boiler from the start, I have been offered a grant of 4200 euro from SEI to install a Gercros 40 pellet boiler.

iplogger1

I don't have the warm & fuzzy feeling about the wood pellet boiler
option (at this stage). I'd be happier to wait for the market &
technology to mature. I've heard stories where folks have been
told that based on their size of home the wood pellet boilers
aren't sufficient in their own right to provide heating for their
overall house (needs to be supplemented). I would also watch
the whole economics of the wood pellet costs. They are being
transported from Fermanagh and so they cannot be immune from
oil/petrol price rises. There is the maintenance side -- need to
shut down frequently enough to empty ash,etc.

I'm interested in your research - why did you rule out heat
pumps for your build ?

bbbaldy

I ruled out heat pumps for the build as it is dependant on Irish electricity which in turn is dependant on fossil fuels so you dont really get away from the whole oil inflation thing.
I also work with compressors they are unreliable and tend to need replacing (V Expensive) if worked hard, which I believe the heat pump compressors are.

I also read somewhere that after 20years or so the ground arround the geothermal pipes gets cold soaked eventually. (I cant confirm this as fact scource forgotten).

The wood pellet boiler I am ordering is a 40kw which is sufficiant to heat 2750ft2 home on rads, The technology is in use in other countrys for a while now and is quite mature. I am not doing this to be green, it just makes economic sense, as it stands it is cheaper to heat your home with pellets than oil. Ash removal every 3 weeks is a small price to pay. other suppliers are starting up in the republic. A lot of people are taking up this method of heating for their homes now and i think it is here to stay.

iplogger1

Interesting Bbaldy regarding the compressors/reliability/expense
of refitting,etc.

I don't want to draw parallels too far but my car air conditioning
went bust because the compressor packed in after 3yrs and
it just wasn't worth the investment for me to get the compressor
re-fitted with pressurised gas,etc compared to the value of the
car. I know in engineering you have these mtbf figures like mean
time before failure and probably mine failed prematurely but it
does make me a little nervous about longevity of pumps which
need to work hard. I don't want to fixate negatively on the heat
pump technology but this is a slight concern to me also. I stand
corrected but I would suspect that the heat pump possibly has
to work harder in the Irish climate compared to the ones where
heat pumps have been proven to be successful already.

I definitely don't want to throw mud here because I still haven't
ruled out the heat pump as a possibility and what I know
about heat pumps has been learned in about 3 months of
research talking to users, experts & anecdotal stuff. Most people
who have the system are extremely positive about it mind you.

When you mention your pellet boiler heating system are you heating
regular panel rads or underfloor with that ?

~ipl

Viking House

Hi iplogger

If you insulate your house properly using good insulation with a high "Decrement delay" then your heating costs using oil will be less than €400/year. The same size house as yours in Finland has heating costs of about €800/year.
Using these figures the case for Geothermal becomes very small.

bbbaldy

Panel rads, possibly aluminium, I need to find out more about the aluminium corroding (Lifespan of the rads).
Re the heat pump, another reason for my dislike of the heatpump/geothermal system is, after many years of engineering within a broad range of technologies, I just dont like it, it just dont do it for me. I really feel its being talked up a bit too much.
Nothing scientific in these assumptions but hunches have worked well for me in the past.

iplogger1

Viking House wrote:

Hi iplogger

If you insulate your house properly using good insulation with a high "Decrement delay" then your heating costs using oil will be less than €400/year. The same size house as yours in Finland has heating costs of about €800/year.
Using these figures the case for Geothermal becomes very small.

Hi VikingHouse :

I probably am a bit constrained with respect to how much I can
go to town on insulating the house.
We've gone past the planning approval stage and the house is
2 storey standard block construction with block/cavity/block.
I'm guessing you are hinting at possibly timber frame almost
hemetically sealed with some insulating render on the outside
and perhaps using a heat recovery ventilation system.

Best I can probably do is to up the spec on the attic/roof insulation,
choose very good insulating properties of glass for windows.
I've gotten quotes for internal dry lining but I've seen in your
interesting posts that you see that as a sweaty/poorly effective
solution to insulation of a house in our climate. Also I assume
our cavity insulation will be kingspan or xtratherm and I think
your take (I might be wrong) is to avoid these materials at all
costs.

I'm interested in your suggestions on how I can increase the
insulation but remember I haven't got a blank sheet to work
on here. Our choice of block build and planning restrictions on
how the external finish of the house looks would prohibit some
of the suggestions you might have in mind - but I may be
mistaken.


~ipl

Viking House

Hi ipl

If I was building a block house I would use 9 inch cavity blocks and insulate the wall on the outside. You will save money by laying only half the amount of blocks.

When you plaster onto the insulation the finish will look exactly like a block built house.

I am not saying to avoid Xtratherm or Kingspan at all costs, just not inside the living area.
Their U-value is cut in half when you use them in the cavity because you always get an airflow between the insulation and the cement block.

If I had to build a cavity wall in a house I would use Rockwool bats in the cavity as insulation.

iplogger1

Anyone else consider heat pump/geothermal and then chicken out
to install oil fired rads and put more money into insulation?
I'm kind of playing devils advocate because I've not 100%
made the decision on going with geothermal hp/ufh.
qwerty and yop have done a fairly good job in selling me
the geothermal route but I'm not just there yet in closing
decisions. Last minute doubts setting in.

Tell me why my plan B using oil fired rads, solar collectors
for hot water in spring/summer, a nice multifuel stove
in the living room and a good deal of insulation above building
regs is daft or ill conceived from an economic point of view.

This plan ditches underfloor heating altogether but that
wasn't a strong requirement to begin with.

towbar

We are on your plan b. Not moved in yet so hopefully works out.
All rads piped seperately back to UFH manifold.
Thermostat in each room controls manifold actuators. (Heatmiser)
Dual coil tank to facilitate solar later.
Wood pellet with buffer tank - option to add solar here also. - Bought a second hand oil boiler until pellet boiler ready- will also use as backup in event of lack of pellets. Our selected pellet boiler will also burn oats and barley.

Left option to add pellet or wood stove to main kitchen\dining room. - Large open plan room with vaulted ceiling.

Impossible to know what heating cost will be.
Ruled out ufh due to living style, house not occupied constantly and also didnt like the idea of heat underfoot.
Although this didnt rule out geo - it steered us against it - also wild stories on esb bills although I think many of these stories are experiences of first few months only until system stabilises and house drys out.

Considered fan assisted rads which work on low temp http://www.lowenergy.ie/ but ruled out due to running cost and potential noise source but would consider again.


If you need more info let me know

iplogger1

Towbar,

Interesting setup you have described.

What is the advantage of room stats and UFH manifolds versus
say TRV valves on each rad. I am not too well up on central
heating system plumbing. How would the manifold/room stat
combo outshine compared to stats on the panel rads ?
Is the UFH manifold setup expensive. Do you mind sharing
a ballpark figure for the extra expense for that aspect of
the heating system ?

~ipl

towbar

iplogger,

Interesting story - probably no real advantage I think the cost is similiar.

We were going timber frame and builder planned to pour finished floor with the base before frame was erected so I thought we'd put the pipes in the floor and run back to a manifold so there would be no joints in the pipes under the concrete as no way to pressure test at that stage. As it turned out builder felt it was easier to do a sub floor and lay the pipes aftewards. By that stage I had specified the system for the plumber and we didnt bother changing.

As to cost I dont know exactly what the breakdown is for manifolds etc. Total plumbing cost is 14k for 4 bed bungalow 1 ensuite, 1 bathroom and 1 small toilet room so not unsually high. I have a 10 port and a 6 port manifold, 16 radiators in total. Thermostats, clocks and control panel from heatmiser was just over €1k which I purchased seperately.

The house I am in currently we added TRV's and I think they are good but the system is not zoned so the whole house is heated at the same time.

The new house will allow different temepratures in different rooms at different times of the day.

We only use 3 bedrooms so 1 room will be set to 10 degrees all the time, kids room will warm up from say 6 in the evening, our room will warm up from 9. Sitting room will remain low unless we manually up the temperature. etc.

There are probably too many options however the stats can be programmed via a master clock and profiles can be copied from one to the other or you can program via computer. The aim is to only have heat where and when it is needed.

It did end up with alot of pipes in the floor and if doing again I would probably use a motorised valve on each radiator and wire the controls back centrally, certainly easier to run wire than pipes!! Its hard to know which would be more efficient though, more pipe installed but given that only one or two radiators may be drawing heat at any time on a zone the water circuit will be shorter with the manifold solution. Placement of the manifolds is important and although we didnt consider it at the time the two manifolds are almost dead in the centre of each zone miminising the lengths of pipe that had to be run. I also have to make sure nobody tries to turn off a radiator locally as it could cause problems if that was the only radiator active on the zone. I will install blanking caps on both ends of the radiator to do this. Come to think of it the plumber could have saved me some money there and not installed radiator valves at all as the manifolds have an actuator on one side and adjustment for balancing on the other side.

We also used systemzone from systemlink for zone distribution. Hope it works!!! but if it does it seems a very simple piping system for zone management - no motorised valves required.

PM if you want to talk through the detail of this or if you want to see the setup, new house is in the North East.

jdh

Hi folks. I'm new to this thread, and new to Boards as well. I've built a 4300 sq ft house, and am in a similar position on heating, as I've not installed yet. I've gone for UFH up and downstairs. I'm putting Rads in the attics, some out of sight alcoves and towel rails in 5 bathrooms. I felt there were a few cowboys in the Geothermal game, and wasn't inspired with the overall idea, or the associated costs. In the end, I'm going for an oil boiler,for a start, but plan to migrate to wood pellet, at some point in the future. I share the concerns about this technology being talked up in Ireland at the moment. I'm installing a 30kw hercules solid fuel stove in my primary room. This monster is sufficient to supply 22 rads.
The stove and the oil boiler will both directly supply a 280 litre tank. The tank has a 3 coils, which feed the UFH manifolds (of which I have 3). All domestic and heating water will come from one tank, no buffer needed. Hence, the boiler will only come on, if the stove is not meeting the demand. However, stoves are inherently risky and uncontrollable, so the rads in the attic provide release, in the event the stove is cranking and the stats are all off.
I've gone for 2" in cavity and 4" Quinntherm in the attics and all ceilings.
I though about drylining, but having huge windows, it didn't stack up, si O upgraded the windows.
You folks sound very knowledgeable on this, and I'd really appreciate any thoughts you have on the merits of this format.....

De_man

jdh wrote:

I've built a 4300 sq ft house, and am in a similar position on heating, as I've not installed yet. ......I'm installing a 30kw hercules solid fuel stove in my primary room. This monster is sufficient to supply 22 rads....

just wondering is 30KW unit enough? would 40KW be more suitable?