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Energy efficient heating

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4 replies
  1. Jim and Vickie Scolari
    Jim and Vickie Scolari says:

    My wife is a wheelchair user and spends 3 hours in the bathroom each morning. She needs a warm bathroom. Our bathroom is an add on and is built above a 15′ x 10′ crawlspace. The rest of our home has a basement. Our home has base board hot water heat using a boiler. To make the bathroom floor warmer, we had 3 five foot heating elements with fens added to the boiler system in the crawl space. We also installed “double bubble-double foil tempshield foil over the crawlspace floor and side walls. The boiler does not run often enough this time of the year to determine if what we have done will warm the floor. So far, after 2 weeks, it has not. The crawlspace is now at about 68 degrees and the bathroom is at 71 degrees while the bathroom is also 71degrees. Do you think what we have done will raise the heat of the floor tile in the bathroom? Maybe,we will have to wait until October to find out when the outside temperatures increase. Thank you for your thoughts.
    Jim and Vickie from the State of Illinois.

    • Robin
      Robin says:

      I’m not sure I understand some of the particulars here – 1) is the crawl space only for the bathroom (ie. is the bathroom 15′ x 10′)? 2) if the bathroom is smaller than the crawl space did you put the extra heating elements throughout the crawl space or concentrate them under the bathroom 3) are the heating elements on the floor, against walls, or close to the ceiling? 4) is the reflective insulation the only insulation in the crawl space or was it added over top of a decent R-value insulation against the walls?

      It seems to me that if the goal of heating the crawl space is to heat the bathroom floor, you want to (A) minimize heat loss to the outside by ensuring you insulate with something more than a radiant barrier – e.g. 4-6″ of mineral wool or fiberglass along the walls to get to R-13 to R-20, and (B) concentrate the heat source close to where you want the heat – ie. close to the ceiling of the crawl space directly under the floor.

      Also if your crawl space was built properly it should have insulation in the floor below the bathroom, which is going to reduce heat transfer from the heat source to the bathroom floor. The ideal solution if you want a warm floor would have been to install radiant heating in the floor itself, but that train may have left the station. Anything you can do to direct the heat towards the bathroom floor – moving the source closer to the bathroom floor, removing insulation barriers between the heat source and the floor, and adding insulation barriers to the outside and to other parts of the crawl space – will help.
      From your description I can’t tell if what you have now will give you the comfort you want in winter, but your doubts and experience so far suggest it may not. It sounds though like it should at least be an improvement over what you had before.

  2. Tim Bainter
    Tim Bainter says:

    I’m a landlord who owns several old flat-roof city multi-family buildings. All of the buildings were rehabbed ~2012. furnaces are mostly 2012, but the crooked contractor slipped in some furnaces from 2007. All windows were replaced in 2012. 2 buildings have new roofs installed last year. I have had several tenants complain about utility bills. I looked into utilization at the electric company and the bills seem generally high. i don’t see any one characteristic that causes higher usage (e.g. the units with the 2012 furnaces don’t appear to be materially more efficient than the 2007 – ~10% when adjusted for relative sq footage). Both downstairs and upstairs units have bills that are too high.

    Buildings are brick and tuck pointing is in decent shape.

    My contractor was a crook, so I wouldn’t be surprised if he cut corners. What else is there that I can do (hopefully within a reasonable affordability) to improve energy efficiency. My tenants in a 1000 sq ft apartment averaged ~250/month in electric bills from Dec1 – Feb 29 last year. The highest monthly bill was $350!

    Where do I start with something like this?

    • Robin
      Robin says:

      Without looking inside the apartments I can’t give very concrete guidance. I would suggest hiring someone to do a home energy audit on some of the apartments where the tenants complain most about electricity bills. You have furnaces, and the newer ones are more efficient than the older ones, which means they are not electric furnaces, so the high electricity bills are probably because the tenants are using electric heaters to supplement the heat from a gas or oil furnace. (If they are electric furnaces, then there is no difference in efficiency, since all electric heaters/furnaces are 100% efficient at converting electricity to heat.0 This is further confirmed by the bills being highest December through February.
      A home energy audit would (among other things) do a blower door test to figure out where drafts in the apartment are letting warm air out and cold air in. Plugging drafts is relatively easy and can save a lot of energy. You could also invest in an infrared heat gun to walk around the apartments on a cold day and take measurements of outside walls, window seams, and so on to find where the cold areas are. It may be the crooked contractor cut corners on insulation or on proper sealing. You or your tenants may want to invest in better window coverings as a lot of heat escapes through windows, and proper blinds or curtains can cut back on those heat losses.

      I gather you are based in Missouri, which has a state website devoted to certified home energy auditors. Look for one in your area and give them a call. Note that there are some personal income tax advantages to having a home energy audit, but I’m not sure how you would take advantage of those as the landlord. One option that might work is to get the tenant to pay for the audit, and for you to provide them with a corresponding reduction in their rent. But I haven’t looked into the program since I don’t live anywhere near Missouri.


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