Heat, cool, and ventilate an old house in California?
LOTS of stuff in here for the north and east, not so much for us in the Southwest. I am restoring a 1903 Vic in San Pedro, on the coast near Los Angeles.
I have worked very hard to seal and insulate it. Iso foam in exterior walls and under roof. Redone double-hung windows, added STORM windows (those years in Minnesota taught me something). Lots of radiant barrier material etc etc.
NOW I still need a little cooling and heating a few months of the year, and ventilation since we are sealed. In my area “fresh” air does not come from outside…. if you want it, you have to make it. I figure I need a lot of air filtering and ventilation, and a little heat and cool, and would prefer to minimize impact on the history of the house. Suggestions gratefully received.
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John,
For more information on ventilation, see Designing a Good Ventilation System.
For more information on space heating options, see Heating a Tight, Well-Insulated House.
Read your blogs, both of them very carefully. Still have the same problem another commenter noted, not enough about how to deal with desert climates. I think that what I need is something like a Recouperator which can filter and circulate the air. It can also be set to bring in cool air at night which will address some of the cooling. It appears that I also need a heating/cooling unit which can be ducted to bring cool air to the top, and warm air to the bottom of the house, and then let the Recouperator circulate that air. Does this make "general good sense"?
John,
I urge you to think separately about two systems in your house. Your heating/cooling system should be separate from your ventilation system, so there is no need to complicate your life by mixing the issues together.
In your climate, cooling is important. That means yous heating/cooling system will probably deliver heat through forced air ducts (to allow cooling as well as heat). This is the conventional approach in most U.S. homes.
Some superinsulated homes are using ductless minisplits instead. While somewhat unconventional, such systems have the advantage of simplicity and very high efficiency.
If you stick with a forced-air system, your supply ducts can deliver supply air near the floor (optimized for heating) or near the ceiling (optimized for cooling), but it is difficult to install ductwork that can do both. Either way, if you choose the proper registers and if your home's envelope is airtight and well insulated, you will be comfortable.
With a conventional forced-air heating/cooling system, you have two choices when it comes to supplying heat: a furnace (fueled by natural gas, propane, or oil) or an air-source heat pump (fueled by electricity). Either system will keep you comfortable.
Cooling is conventionally supplied by a split-system air conditioner that delivers cool air through your ducts.
Now you've designed your heating/cooling system. It's time to design your ventilation system. You seem to like the RecoupAerator ERV; that's fine. If you end up with an HRV or an ERV, you'll have a top-of-the line ventilation system. I urge you to use dedicated ventilation ductwork -- not the same ducts that deliver heat to your rooms. Supply fresh ventilation air to your living room and bedrooms, and pull stale exhaust air from your bathrooms, laundry room, and perhaps your kitchen (but not your range hood).
OK, you are done.