# heating sources



## dgeers (17 Aug 2011)

Hi 
Anyone out there with a solarpst (Google it) installation  in Ireland , looks good  but I would like to hear / see real world experiences

also on the subject of heating sources -  we are planning to build a new house with +++ insulation + HRV. We are a bit baffled with the stories and the advice we're getting ( for example  back boiler on a stove for hot water is not worth our while ?) 
We like to be green but not at a massive cost , and ROI needs to make sense

house is around  272 square meters  4 bed rooms , no underfloor heating we are planning to go with ALU rads both floors and above mentioned PST or other solar panels and  back upheating with stove(s) or oil

if any one could share a bit of experience that would be great


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## serotoninsid (17 Aug 2011)

Is this technology related to that of an air source heat pump?


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## Shane007 (17 Aug 2011)

dgeers said:


> Hi
> Anyone out there with a solarpst (Google it) installation in Ireland , looks good but I would like to hear / see real world experiences


 
It's basically a fridge working in reverse. It has a compressor that will be on 24/7 to compress a gas within the system, and therefore generating heat. From what I gather, they are high on electricity and should not be called "solar" technology as they have nothing to do with the sun.

There is a company here in Ireland with an extremely similar product. Would stay well clear!


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## serotoninsid (17 Aug 2011)

Shane007 said:


> From what I gather, they are high on electricity and should not be called "solar" technology as they have nothing to do with the sun.


so I am right.  It is an 'air source heat pump'.  I spent a long time reading up on this too (and ground source heat pumps) and like you, I can't see how they could possibly be marketed in this manner (ie. the 'solar' inference).  Just like domestic solar and domestic wind, they're simply not viable yet.


Very frustrating with all of these technologies right now.  Even though vendors will tell you the opposite, the reality is that they don't stand up to through scrutiny in terms of payback calculations.


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## dgeers (18 Aug 2011)

Thanks all for the responses.  I had doubts although it seems to be a success  something tells me its not entirely above board. The reasoning is that the collector collects the heat ( liquid > gas) and the compressor compresses the gas to liquid = heat. The thing is that if the collection of heat would be working properly and the panel gas is - 10 there would be surely  ice build up ? as to move from one state to another you need energy hence temperature on the panel would drop to come from fluid to gas = ice. The heat that is created is coming from the compression cycle  what is entirely correct but the panel is playing second fiddle 

So what leaves me with not much , solar panels  ROI is  bad as it is ( 11 years) what else  could we use for being green , wind  not a runner as I'm ready to move to bog standard LPG or oil and just insulate the heck out of the house and see what the effect is

Any suggestions are welcome .


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## serotoninsid (18 Aug 2011)

dgeers said:


> The thing is that if the collection of heat would be working properly and the panel gas is - 10 there would be surely  ice build up ?


Yes - and to prevent the ice build-up, most of these units are geared to prevent this - but there is a significant electricity expenditure involved in this.  Vendors will tell you otherwise, but I'm yet to be convinced that they are viable (and viable to me means that they can achieve payback over a reasonable timeframe). 



dgeers said:


> So what leaves me with not much , solar panels  ROI is  bad as it is ( 11 years) what else  could we use for being green , wind  not a runner as I'm ready to move to bog standard LPG or oil and just insulate the heck out of the house and see what the effect is


I've come to the very same conclusion.  I keep checking back with these technologies in the hope that they will make the breakthrough and become feasible / viable options....and you'd imagine that with the intense focus on wind/solar, etc that they surely will become more efficient - but it's a case of waiting it out.  Until then, as you say - insulate the hell out of your house - and work on airtightness where possible.

The one other option that I had pondered some time ago was Heat Recovery Ventilation (HRV) - and whether this could be worthwhile (i.e. viable).  Would welcome any insight on this that folks may have ...particularly in terms of retrofitting.


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## dgeers (18 Aug 2011)

Hi 
we are going  HRV but do not expect miracles out of it , rename it to controlled ventilation and you are much closer to the truth, yes it can pick up from the outbound heat but we're talking low amount of heat recovery

learned so far 

- go with manifold design , e.g have unique connections to each room  do not fork off the inbound and outbound pipe  as you need to clean them 

- smooth pipes as ribbed pipes collect dust

- plan in-takes and output points correctly , intake never above a heatsource

- use a softball to clean the pipe ( beach ball tennis ball) ,clean filters every 6 months iif needed and this is depending on the house location


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## hastalavista (18 Aug 2011)

*some doodling on HRV*

HRV:
Air-tightness is key: this is what makes retro for full HRV a non runner in most cases

metal ducts

Proper sizing for minimum head loss

auto-shutdown in case of fire

easy access for cleaning filters

quietness of motor, location of unit is key

What happens if the beach ball gets stuck: you call the Hoff and Pamela A


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## Construct (4 Sep 2011)

In designing your house look at Passive House standard. A passive house has a high level of thermal comfort. It is based on minimising heat losses and maximising heat gains. The only essential energy technology required is a HRV system. Put fabric before technology. As hastalavista put it air tightness is key.


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