I am buying a house in the uk, it is a bit of a wreck and one of the first jobs will be to plumb and wire from scratch.
in the future I would lilke to plug in some auxillary sources of heat such as water-heating solar panels or a masonry stove with water heater.
My question is which is the best plumbing layout for doing this- I want something resilient and cheap to maintain so I favour vented systems, if I understand correctly this rules out combi boilers (unvented) and system boilers (they heat the central heating directly so my preheat energy will be innefficiently used). I have seen this on builditsolar- it looks absolute genius:
this seems to work with a vented regular old-fashioned boiler system and a tank/boiler that can handle the incoming 'cold' feed actually being warm.
boiller manufacturers all seem to recommend the combi for most applications, especially if you don't have a loft space- and I don't.
can I achieve what the build-it-solar guys have done in my situation?
whatever I do, all the major plumbing hardware would be on the basement floor and the water pumped around.
any help navigating the confusing world of boilers would be really appreciated.
Howdy Dave, congrats on your purchase. From what I understand, UK space heating and water heating is done differently than most of the states. The new england areas have the most "combi" type installations that you would see over there.
For the most part, most high performance building is moving away from this type of set up due to costs, complications and inefficiency. However, since they are common in your area, it might make sense to stick with that type of system especially if you are using any existing infrastructure.
The builditsolar system you referenced is in Montana which has a very sunny climate. If you are comfortable with DIY plumbing then go for it but Iam sure your cloudy climate will hurt the payback. There is also an increasing trend going away from solar thermal water due to high costs, trouble prone installations and high maintenance.
Heat Pump water heaters are very appealing in much of the states and may be worth looking into.
"If you want to save the environment, build a city worth living in." - Wendell Berry
posted 6 years ago
the link you posted was all new to me- never seen a heat pump water heater before. as tey say at the end of the article though- it makes most sense in a aspace cooling/water heating scenario, and in the UK that is not common.
interesting that they mainly discuss this tech versus electric resistane heating, in the UK mains-supplied north sea gas is pretty much the standard for heating, it's a little bit cheaper than electric from the meter, but of course there are greater installation costs- I am not going to DIY a gas installation!
you have prompted me to have amuch more analytical look at this though- there are obviously other technologies around with different setup costs and payback times- perhaps I should get creative and look beyond a £3500 gas central heating installation.
I haven't seen those pipe manifolds before either- suggests water from solar water heating system coming straight into the supply to the taps, any system I will be using won't be mixing withcold water, it will be going into the water tank to be brought up to the minimum temperature.
I've just installed a heat pump water heater. Natural gas is cheap here, but many miles away from my house. Bottled gas is much higher than electric power.
So far, I've seen about a 15% decrease in my electric bill and an almost 100% drop in humidity in my basement (where it is installed).
I use a hydronic air handler with a tankless gas water heater. It is 96% thermally efficient and handles both space heating and water heating with one appliance.
I did it myself, including a whole house electrostatic precipitator and all new PEX plumbing for under $4000.
If I could do it again, though, I would stay away from BRANCH plumbing using PEX manifolds, and would instead do a parallel loop circuit, so that a on-demand hot water reciculator could be used effectively. Right now I have a hot water recirculator that delivers hot water to the "master" bathroom sink on the press of a button, but because I used manifolds, it ONLY provides instant hot water to the sink, not to the other 6 branches of my plumbing system (unless I also install bypass check valves and wiring to each of those branches as well)
Another good thing about tankless heaters is that, if you wanted to use solar, it would still work. In that case, the tankless heater only heats the stored hot water up to your desired temperature if it isn't yet hot enough from the sun. So, no cold water on cloudy days. The two things may not be able to work together, though, the hydronic air handler and solar... Because the air handler needs water at 160 degrees F to meet its RATED BTU output. Of course, you could just oversize the handler and use cooler 120 degree water for the same BTU output.
posted 6 years ago
hi, just feeding back that what I think I need now is a vented condensing combi boiler that is fully modulating.
this is a common, not too expensive system that is tankless so doesn't take up much space and doesn't store hot water- no cylinder losses. the fully modulating capability is what will allow me to safely feed in preheated "cold" water.
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