I live in Oakland CA, in a 1351 sq. foot 1919 bungalow, and am getting ready to convert the three floor furnaces to gas, force-air central heating (not DIY — I’m getting estimates now). I do not plan to install air conditioning.
1. Should I consider getting a humidifier? In the midwest, this was a no-brainer. So far one contractor has suggested it, and another didn’t mention it.
2. Should I get a thermostat designed for heating *and* cooling, so I can run the fan alone in the late afternoons in the summer? If not, how can I run the fan without the heat? I’ve heard that heating system thermostats don’t have a “fan only” setting.
3. Other than energy efficiency, are there any significant issues with oversizing a heating system, analogous to the humidity problems with oversizing a cooling system?
4. Does it matter whether the ductwork is rigid sheet metal versus flexible ducting?
5. What should I make sure to have included in a contract?
It seems every time I look for information about installing central heating systems, most of the discussions are about sizing *air conditioning*, with heating system sizing being an afterthought. My house does NOT get particularly hot in the summer, as outside temperatures are rarely above 85 degrees (typical summer highs are in the upper 70s, and lows in the 50s or 60s). Also, most discussions that I *do* see about heating are about heating in extreme climates. The winters are mild here, too — nights in the 30s or 40s, days in the 50s or 60s.
Thanks for any help.
Replies
When I lived in Oakland I used to have HVAC work done by Superior Comfort Systems, down in the Hayward/San Leandro area. A man named John was my contact, and I wish I remembered his last name. They installed complete systems, expanded systems, did repairs, and did a lot of nice architectural sheet metal work for me.
If you oversize the system, it may short-cycle. Have the contractor size it correctly for what you need. Invest in insulation as well... it's worth the money you pay for it.
You should ask your contractor what work they will exclude, and what you will need to contract for separately. They may not do the electrical and gas hookups. They may not cut the holes in the floor for the boots. There are other things they may not do. Ask for a complete list of exclusions, in writing (and by default, a complete list of everything that is included too!).
Flexible ductwork is typical in most places. The return air duct will be rigid.
Do your homework with regards to the brand and quality of equipment they will install. There is quite a wide range in terms of equipment quality. My subcontractor here can install a system for $15,000 or $25,000... same house... what equipment do you want?
If you need other subs down there let me know.