I have a 1500 sf bungalow w/very poor heating efficiency. We’re looking at replacing or enhancing a lot: insulation, storm windows, furnace (currently a monster-sized converted coal furnace), etc.
Our primary goal is environmental–conserving resources and reducing pollution–our secondary goal is lower energy bills over the long haul.
Anyone have experience with the performance of solar roofing tiles? We need a new roof. We don’t mind paying more for “green” improvements, but don’t want to invest in something that’s not going to last or deliver for long.
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I saw a house that used them. I was real interested in how they worked etc. yet from what I gather, they were't very successful. Seems like the power companies truck was frequently there & reportedly the energy output wasn't anywhere near anticpation.
Now that is hearsay comments from the contractor who built the house so I have no actual information. Personally I'd like to see the concept work. If anyone has some actual experiance I too would like to know about it.
I'm not in the HVAC business but I am an Electrical Engineer that has been renovating an old home in New Orleans for the last 11 years. I have done most of the things that you talk about doing and more, both to save money and the environment. After reviewing the time and money spent on these projects I have come to a conclusion.
In many cases, houses were built the way they were for very good reasons. For example, my house had open bay studs from under the house to the attic. This was for two reasons, one was to allow the cool air from under the house to naturally convect through the walls as they were heated by the sun thus cooling the walls. The other reason was that New Orleans has incredible humidity and the air flow was great for drying out the walls after a rain storm. Now I did insulate the walls but only in the course of a complete re-siding of the house where the walls were opened up and a vapor barrior was used to keep the walls dry. The house is quieter and my AC bills came down but not buy as much as I expected. I could site other examples but I still wonder if closing in the walls was the right thing to do. If any water gets in the walls now I'm cooked. The mold and rot will be uncontrollable. IMHO, by far, the best money spent for a renovation aimed at energy efficiency would be to install a ground source heat pump. Just let it make lots of cold or hot air cheaply and keep the house original. Since you will be putting in heating system anyway, and you will probably opt for a higher efficiency unit, the extra cost will be incramental. This will save you much more money and be much less effort than putting in a high efficiency furnace and double pane windows. The problem most people have is that they do not have the space to get the tubing in the ground. I do not work for these people but I have visited their factory and think that they have a great product. Don't do the average thing, do the best thing. Take it from someone who is there right now.
http://www.ecrtech.com/content/
I agree a ground source heat pump does offer some real effiency. yet they are nearly impossible to retro fit into an older house with a well developed smaller yard. That is unless you want to tear up something that may have taken decades/ centuries to grow.
Thanks for the link to ECR Tech. I have been researching ground source heat pumps and find that ECR's system makes sense. I even spoke with a rep (driller) for them out here and he claims our yard would be minimally impacted because of the small copper pipes and downward drilling versus using PVC and having to move a lot of earth.
I just haven't been convinced that a GSHP is the best option for us. We don't have A/C and don't really NEED it (thanks to the design of this lovely old home w/thick brick walls and great orientation to the sun), so we have about $25 utility bills in the summer for gas/electric. Our heating bills in the winter are astronomical, though. Ridiculous. The utility guy who came to look at our furnace says these old converted boilers are about 20 percent efficient.
The way I understand it, the GSHP fan, compressor, etc. runs on electricity, and that's where I get stuck. I don't know how much electricity the unit would use when in heating mode (bumping temp up from 53 degrees), plus I'd have to retrofit the house w/miniducts for an added cost. Currently I have hot water radiators. blah blah blah. It's all a big research project for me at this point.
It's kind of exciting to see the new products popping up out there. Found one web site where a clever passive solar system is used: Concrete or slate or other substantial roofing tiles are laid several inches above the actual roof. The airspace below the tiles becomes heated, and that heat is drawn down through some kind of duct. Very interesting.
The ground source heat pump can heat the water for your baseboard heating. It can also heat your water. Of course to get cooling out of the system you would have to install some sort of air handler. It is actually more efficient to heat water with a ground source than with a high efficiency boiler.