Underground pre-insulated pipe price?

Just to declare my interest, I work for REHAU who make the RAUVITHERM / RAUTHERMEX pipes mentioned. I know this is an older thread but there are a few points to mention. Some comments refer to RAUVITHERM having 'double the heat losses of RAUTHERMEX' or 'RAUVITHERM having awful heat losses vs Uponor / Flexalen'. This is due to our heat losses for DUO pipes being calculated for many years on flow AND return losses, whereas many of our competitors use just the flow pipe losses. This is why the heat losses appear ca. 50% worse than our competitors whereas in reality our competitors have similar heat losses to us and in quite a few sizes, we have actually lower heat losses. Always important to check you are comparing like-for-like parameters and we've now changed how we present this information.

To put this into context, take a 32mm DUO pipe. Using a typical flow / return temperature of 80/60C (at 0.8m installation depth, 10C ground temperature, 1.0W/mK soil conductivity), RAUTHERMEX, our premium product, has heat losses of 11.0W/m. RAUVITHERM, our more flexible pipe, has heat losses for the same size of 15.5W/m. I'm not going to write any competitor heat losses for a 32mm twin pipe on here as that I feel is not appropriate but feel free to check the competitors literature yourselves to see how it compares.

In real terms of heat losses as someone mentioned heating the ground with RAUVITHERM, a 200m run of 32mm DUO pipe, we estimate the following temperature drop from our heat loss figures (based on 80/60C):

RAUTHERMEX - 1.17C (Kelvin actually to be scientifically correct!)
RAUVITHERM - 1.60C

Not much in it as you can see.

Steve

P.s. Apologies for the joining the discussion as a supplier, but as you can imagine from our point of view, it's important to correct any possible misinformation being quoted about our products as ours were the main focus. I have tried to present facts as clearly as possible and not be a sales pitch.

Steve,

its nice to have the facts from the horses mouth, thank you. Too many 'experts' on here, most appear very good but I know of a few who could be classed by some as dubious!

would you like to comment on Uponor and the heat loss differences vs costs between yours and theirs?

I only ask because a) I have just used some and was advised that it was OK and b) I may have another project and like learning the facts for myself!

Ref Eco Biomass's figures, I wouldn't worry too much, he thought iron pipe in the ground was as good as Uponor... http://thefarmingforum.co.uk/index.php?threads/uponor-heat-pipe-discounts.48058/#post-1024138

We have 2 pipe runs. One long and one short. We have gone for the Brugg Calpex duo pipe which has some of the best performance figures but is very expensive. When your spending large sums on the setup costs though its important to get this right for a good return.
I would add that installing 135m of Brugg Calpex pipe 1000mm deep was one of the hardest jobs I've ever undertaken though! Its a very unforgiving pipe, difficult to bend and you need to select it for the right reasons.
For our shorter pipe run we could have easily used the rehau as the flow rate will be very high and heat loss will be negligible inside the pipework.

It's really right for me to provide direct comparisons in a post so I've provided our data below on a few pipes sizes for you to compare yourself. To help out though, here is the link: https://www.uponor.co.uk/download-centre.aspx Ecoflex Technical Guide April 2014 (page 46-47).
REHAU data is from RAUVITHERM & RAUTHERMEX Technical Manual pages 49-50. http://www.rehau.com/download/1347030/rauvitherm-and-rauthermex-technical-manual.pdf
32 DUO at 80/60C:
RAUTHERMEX 11.0 W/m
RAUVITHERM 15.5 W/m
63 DUO at 80/60C:
RAUTHERMEX 14.3 W/m
RAUVITHERM 23.0 W/m
110 UNO at 80/60C:
RAUTHERMEX 17.7 W/m
RAUVITHERM 24.5 W/m
@farmerfred86 Our RAUTHERMEX pipe uses the same type of PU foam with very low heat losses as the Calpex product and yes on the larger pipe sizes on a cold day, it does require more manpower to install. Typically 600mm cover (800mm for traffic loads) is all you need though?

For shorter projects, the difference in heat losses between our two pipes is quite small so the flexibility of RAUVITHERM can benefit the installer. The comparison I made in my first post was for a pipe run of 200m so less than half a degree difference between our pipes. However there is no hard and fast rule on which of our pipes to use on a project, we offer both systems and let the client / installer choose.

tullah said:

I've seen some very different prices for pre-insulated pipe per metre. What's the going rate and which are the best value that conform to the RHI? How does one get it trade?

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Hi, we specialize in biomass installations from 150 up to 950 kWh for dryers, heating and process heating.
If you can let me know more about your application I can give you the correct prices.
Thanks,
Darren Wright
BDM
Ashwell Biomass

We have just learnt that by using the Brugg calpex pipe our heat losses are so low on the pipe runs that we will only require one heat meater at the boiler!
It makes all the hard work of installing the calpex worth it knowing we won't have to run round 3/4 meters each time!

tullah said:

I've seen some very different prices for pre-insulated pipe per metre. What's the going rate and which are the best value that conform to the RHI? How does one get it trade?

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We will sell you it trade but we don't use the cheaper pipe because of heat losses.

Sheep farmer said:

Hi, rhi currently in review with an application for 1 meter with estimated heat loss deducted. I'm told theoretical heat loss is much less than actual. Boiler room is between 2 properties. Both pipes are 32mm. Both have their own circulation pump. Company has agreed to move pump into farmhouse so as it is comes on with heating or demand from hot water cylinder. Told this will save a lot of heat but this is on system with only 25m pipe as opposed to other with 75m and circulating 24/7.
Consellation is that I'm getting paid for heat loss over and above the one submitted by independent assessor. However it still really pisses me off when you don't get what you ask for. My intention was to make it as efficient as possible.
The company is based in central scotland. One of the best known ones.
Thanks

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You should have controls to stop it circulating 24/7 if the end house heat demand is satisfied.

its becoming more and more apparent that a lot of installations are not including basic control systems for best efficiency.

How many projects actually do the heat loss calcs? I imagine for smaller projects they simply don't bother and select reahu pipe to keeps costs as low as possible. For larger projects its essential!

All our installations whatever size start with heat load calcs and systems are sized and designed on that basis. We then monitor heat losses through the heat Meter readings when we deliver chip. So far so good, not had any big losses.

Flexenergy pipe good price I found and deal direct with you.

I know this in an old thread but I'm in the market for around 30-40m of pipe and wondered if anything has moved on in the last 4 years?

you can get your installation changed to heat loss calc and do away with the other heat meters and only have one on the back of the boiler. it has nothing to do with heat loss of pipe, you tell them the type of pipe used and they take the losses off the data you input according to manufacturers heat loss data. we have had quite a few installs changed to heat loss calc and you are usually better off as well financially.