Can't afford Geothermal, whay would you use?

Carb

Hi Folks, I finally got round to updating my budget last night, and the grim reality is that I cannot afford to put a heat pump in at the moment, and probably won't now for a very long time, if ever, as it would mean digging up the site again. So my question is, what would you think is the next best option in terms of been economical. I have looked into wood pellet boilers and solar power without coming to any conclusion, as I'd always planned to put in a heat pump. Is there anyway of using night rate electricity to a certain extent. The house is timberframe and about 3000sq/ft with underfloor heating on both floors and two bathrooms both with baths and mains showers. Any ideas would be much appreciated.

patrido

interesting question... depends on what you're aiming for...

lower heating bills?
lower installation costs?
environmentally friendly/carbon neutral?

i'm assuming from your post that you want to avoid rising fuel prices, and have a relatively easy/cheap to heat house.

don't feel bad about ditching the heat pump. to make these economical you really need to be running it on night rate leccy, and to get the most out of this, you really need to put in a thermal store adding to the up front cost. you're also married to the esb and their every increasing unit rate.

i'm not convinced by the marketing blurb that tells us that the only way to save money is to put in a heat pump/pellet burner/solar panels. all of these have a big upfront investment that most of us will pay for for 20 years at mortgage interest rates. the interest paid is never taken into account when manufacturers wave a short payback period in front of you.

solar: big upfront investment. provides most of it's output during the summer when demand is least. the best way to save money with solar, is to build a DIY panel and use it to supplement another heat source.

wood pellets: great if you want to be "carbon neutral" but the boilers are way overpriced, and they're not that much cheaper than oil per usable kW of heat. plus, when you run out of pellets, where is the nearest supplier, and how long will they take to deliver.

In my opinion, the best thing to do is
1: increase your insulation as much as you can afford, which will reduce the running costs no matter what the heat source. With that size house, spending 15-20k on insulation would not be excessive. Also make sure that the house is well sealed apart from wall vents (no unplanned ventilation). Consider higher r-value windows and doors. Get rid of the any open fires If the house is not occupied fully all the time, then insulation between the upper and lower floors will keep the heat in the zones for which it was intended and keep the running costs down.

2: spend a few quid on heating controls. who is supplying your ufh? if your house is not occupied all the time, or is only partly occupied a lot of the time, then zone as much as you can, and use programmable thermostats to only supply heat to the areas that need it, when they need it. no point heating 3000 sq ft, when 1000 sq ft would do. a weather compensating controller, or an optimiser/boiler manager might be an option to get the system running most efficiently, though you could always add these on at a later stage.

3: You can then put in a basic oil :eek: boiler (not a condesing boiler with it's 15 year payback period) and your running costs will be very low. oil is still cheaper per kw than any other fuel other than mains gas. and the price of most fuels rise and fall when oil does. in a few years time you might have more money to spend, and by that time heat pumps will have higher coefficients of performance, pellet burners will be more keenly priced, and we may have grants for the installation of solar/geothermal/etc.

fatboypee

For wot it's worth, I had a slightly similar issue with costs and heating dilemma's. I wanted lower costs and good economy but could'nt afford the installation of Geothermal or solar, I plumped for excess roof and wall insulation and the floowing heating plan:

LPG Gas boiler with thermostatically controlled and zoned heating
Plus
Wood/Multifuel backboiler stove
Plus
Large secondary Multifuel stove in the front sitting room.

I've not moved in yet so my theory on lower fuel bills is yet to be tested but I'm hopeful that the multifuel stoves in the two areas of the house will reduce my dependence on the LPG..

Not a very envinromentally friendly method I'll grant you but first and foremost my consideration is cost and economy.....

FBP.

Carb

Thanks for the replies. At the moment cost really is key. I had budgeted around 13K for the heat pump, so to be honest, if I could get away with half of that I'd be happy. When my plumber quoted me, he talked about €1000 for a "good" oil boiler. Does this sound realistic. This would leave me with an extra 5.5K to spend on insulation. I'm lucky in that I live beside a Kingspan factory so I have access to their seconds. These could easily be used to fill the walls and the roofspace. I didn't spend much time on the windows, but luckily the window supplier uses Argon filled double glazing as standard. The brochure says that they're apparently 130% more efficient than standard double glazing.???. I would have trouble sacrificing the open fires. I read somewhere in this forum that its possible to shut the chimney if the fireplace is not been used. Has anyone heard of this? Also, how does night rate electricity compare with oil when it comes to heating some of your water, or does it even come close?

CJhaughey

Firstly you need to acertain EXACTLY what U-value the windows are. Are they 2.0? 1.2? You need facts not marketing jargon.
Lucky you living next to kingspan factory, just make sure that the seconds are in fact cosmetic seconds not below-par insulation.
If you have trouble sacrificing an open fire maybe think about a solid fuel stove? at least you won't be losing all your heat up the chimney, and they are much more efficient.
TBH in order to have an efficient house you need, good insulation, sealed from drafts , good heat source.
You will not gain anything from fitting all the latest UFH and powerful boilers if the house loses heat faster than it retains it.
Patrido
I disagree with your statement that solar hot water produces most of the water when you need it least, AFAIK summer means sweat and outdoor activities = showers/baths and lots of washup.
I would use a lot more hot water in the summer than in the winter.

rooferPete

Hi Carb,

If you are looking for cost efficient options except for Geo Thermal you can email me at roofconsult@eircom.net

I absolutely refuse to discuss the merits of any system on line where Mr. Know It All suggests placing concrete blocks in the middle of a floor, naturally enough there was no radiator in the middle of the floor.

Kind Regards,

Peter Crawley,

www.crawleyandsons.com

patrido

CJhaughey wrote:

Patrido
I disagree with your statement that solar hot water produces most of the water when you need it least, AFAIK summer means sweat and outdoor activities = showers/baths and lots of washup.
I would use a lot more hot water in the summer than in the winter.

i assume you are just talking about DHW as space heating is very often turned off during the summer months, when the output from a solar panel is highest. also the energy required for DHW (and to keep it warm in the cylinder) in winter is much higher, due to the lower starting temps.

if you include space heating, then a lot more hot water will be used in winter.

CJhaughey

Patrido
Yes, you are correct in saying that solar with space heating is not efficient.
However not many houses will be able to heat entirely on solar anyway.
so DHW is a good solution for solar panels and is co-incidentally the main ~30% user of domestic energy.

lomb

ufh is a waste of time economy wise. stick with a worcester condensing oil boiler, zoned controls, a circuit thermostat on your dhw cylinder, trvs on your rads, a good wireless thermostat properly positioned, high insulative windows, and excellent roof and wall insulation. i believe the solar water heaters u put on your roof are economically viable so get one of them also, other than that forget it, its money down the pan.

patrido

5k on extra insulation should reduce your running costs very nicely. prioritise the upstairs ceilings, sloped ceilings, floor, then walls. and make sure that it is installed correctly to get the best performance from it.

Carb wrote:

When my plumber quoted me, he talked about €1000 for a "good" oil boiler. Does this sound realistic.

depends on the output required for the whole building, but it's probably ballpark ok. get your ufh supplier to specify how many BTU you need for it, and add in the DHw requirement. don't go by a plumber's rule of thumb, which may not be accurate for UFH.

Carb wrote:

I didn't spend much time on the windows, but luckily the window supplier uses Argon filled double glazing as standard. The brochure says that they're apparently 130% more efficient than standard double glazing.???.

argon fill should be more efficient, but as cj said, check the actual u-values.

Carb wrote:

Also, how does night rate electricity compare with oil when it comes to heating some of your water, or does it even come close?

it's pretty similar in terms of unit cost, but you'd have to remember that apart from DHW for morning showers, it's not exactly providing it at the time you need it.

There's a good comparision of the effective prices of different fuels here...
http://www.sei.ie/uploads/documents/upload/publications/Domestic_Oct_2005.pdf

Carb

Thanks for all the input. In relation to the windows, the product name is "Therma Vista", I don't know if anyone has heard of this. The Kinspan seconds are generally cosmetically damaged ie. sheets broken in half, corners damaged, no print on the foil etc. There won't be any going back on the UFH as the pipes are already in on the ground floor and the upstairs has been designed for UFH. This sort of leads on to another question. Upstairs was originally designed to take two inches of screed, (using heat pump at night and screed would store the heat). My quess is that the screed wouldn't be needed any more as you would want a quicker response time with oil, and just switch it on before bedtime etc. This will probably raise mre questions about flooring, sound proofing as the screed would have provided some sound proofing. If night rate electricity costs about the same as oil, it's sort of irrelevant. I assume if your not heating a large amount of water at night and storing it, as was the case with the heat pump, a samller cylinder will do?

patrido

controlling a ufh system is very different to controlling rads. if you want to be able to switch on and off the heating fairly randomly, or bring less used rooms into use at very short notice, then you might want a rapid response time alright.

however, the ideal way to run ufh, is to be able to predict usage patterns reasonably well, and let the system control itself within those parameters. an optimiser/boiler manager does this automatically, but you can work it out with reasonable accuracy yourself.

say, if you want 20 degrees between 6 and 11 in the evening, with a bit of fine tuning, you might find that setting the timer to operate from 4 until 9 works best. in winter you might add a little more leeway on either side, the opposite in summer. to heat the bedrooms, set the timer to come on for an hour before bedtime.

you can also use setback thermostats to increase the response time. so instead of letting the system cool down completely as you would in "off" mode, you have a "setback" mode, where the temp is kept at about 10-13 degrees. so it takes much less time to get to 20 degrees when required.

if you have very long setback periods and short "on" periods, then setback will not be cost effective to run, but with average usage patterns it will have a minimal cost.

it's really a matter of preference, but personally i would rather have the screed... as you said it will be an excellent sound barrier, and it will absord heat from the sun all day, and release it in the evening. it will keep the house more thermally stable too absorbing any fluctuations.

by the way, you will have an additional cost if using diffuser plates instead of a screed.