Blogs > Tom Miller > March 2010

The Elephant in the Crawl Space: HVAC

It’s big, old, creaky and high maintenance. I’m talking about the HVAC system in our home. And until I tackle this “elephant”, our home will continue to be an energy gobbling money pit.

A couple of things to know: first, the crawl space is actually about 7’ high, nice and dry, and thanks to some pretty leaky ducts, it stays nice and warm in the winter and cool in the summer. Way too much of a good thing according to the experts.

Second thing to keep in mind: sometime in the mid-1960s the home had an addition put on, and it got its own HVAC system. Great, double the maintenance, separate ductwork, etc.

At GreenBuild, an industry tradeshow I visited in late 2009 looking for green HVAC products, I stopped and checked out ClimateMaster geothermal products. And I was impressed. I have known about geothermal heating/cooling for a long time, and several friends have them in their homes, so I was more than interested to learn that it came along with a very generous government rebate.

I contacted the local ClimateMaster distributor and got the name of several contractors, that I called to have them check things out and give me a quote. Along the way the contractors further educated me about the ins and outs of geothermal.

One contractor, Mike Duckworth of Aire-Serv, used my room-by-room measurements to do a thorough analysis of the heating/cooling capacity that would be required to keep the home at a proper temperature. And he planned to remove the smaller furnace and combine the ductwork so we’d only have one system.

This all sounds great, and as we got further into February, the drilling contractor he recommended came out to calculate the location he’d have to drill. Then, all we needed was for the ground to freeze, so his very heavy rig wouldn’t sink into the mud.

Six weeks later, we’re still waiting…but now it’s for the rain to stop so the ground can dry out. Indiana in April and May can be pretty wet, so this may have to wait a while. Very frustrating.

In the meantime, I’m working with Mike to spec out the air filtration system that I will get from Roger Clearman, owner of Air & Energy Products in Atlanta, GA (see earlier blogs about Roger). And Mike is also setting up the geothermal specs to include hot water, with a natural gas assist to get the water from 100-degrees to the 125-degrees we usually set it on.

So, for now, all we can do is wait for the ground to dry out so we can drill the ground loops. In the meantime, I’ll tackle another task on the list: finishing the insulation.

Posted: 3/31/2010 11:52:44 AM by | with 1 comments

What to do about a drafty old fireplace.

Our 50-year-old home has the original fireplace, a site-built masonry fireplace with a raised slate hearth. The original was wood burning, but we converted it to gas when we purchased the home. Very convenient, but as we soon learned, also very energy inefficient.

There are several issues about installing gas logs in a traditional site-built fireplace. We were informed by the company installing it that is was a building code that the damper must be modified to keep it partially open all the time. This would prevent accidentally building up carbon monoxide indoors. Good idea. But it also meant that in cold weather it allowed warm indoor air to escape.

When the fireplace was in use, it seemed that all the heat went right up the chimney, along with more heated indoor air. The room actually felt cooler when the fireplace was on. Definitely not very energy efficient.

So we started investigating, and learned about direct vent fireplaces and that they could be installed inside the existing opening. The concept of a direct vent fireplace is pretty simple, really: The combustion chamber is sealed tight. Two flexible metal tubes extend from the top of the fireplace insert to the top of the chimney. One tube draws in outside air for combustion. The other tube exhausts the vapors created by the fire…probably just like a typical flue on a gas furnace. The result is that almost all of the heat stays in the fireplace, which very quickly provides plenty of heat.

I learned all this at a local fireplace firm called Dealers Wholesale. And I also learned that our contemporary home didn’t have to settle for a traditional looking fireplace. We chose a Heat & Glo brand contemporary design that really fit the style of our home. And its remote control allowed us to adjust the flame so we could control the amount of heat it was generating.


Two weeks after ordering it, Dealers Wholesale called to schedule a pre-installation inspection of the existing fireplace, and the next day the two-person crew showed up to install it. Ninety minutes later, we had a beautiful new, high efficiency direct vent fireplace putting out plenty of heat in our living room.

This was really the first investment in our quest to make our home more energy efficient that was actually pretty to look at. Everything else had been concerned with making the home more air tight and better insulated. But I knew it was all worth the investment. Especially after we had the triple pleasure of: 1) a draft-free, cozy home; 2) extra warmth in the room where we spend a great deal of time; and 3) instantaneous reductions in our gas bills.

But the reality remained: to really make big inroads into the home’s energy usage, we were going to have to address the HVAC and water heating.

Posted: 3/9/2010 9:45:30 AM by | with 1 comments

About Me

Tom Miller is not a building scientist, green guru or even a halfway decent DIYer. However, he is passionate about making a difference, ecologically speaking.

The purpose of Tom’s blog is to share experiences and observations from a homeowner’s perspective in the hopes that it will help building professionals spot unmet needs and dramatically increase the velocity of green building adoption across the country.




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