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Wednesday, August 18, 2010

Doing The Right Thing Is Harder Than It Sounds!

The roofers are at my house today, busy tearing down the existing roof shingles and putting up a new roof. My insurance company is going to pick up most of the tab for this, except for the deductible. Initially, I had thought of replacing my roof with a certified one that would qualify for the tax credits for energy efficient construction the government is offering.

Unfortunately, my contractor did not know much about these tax credits. So, I had to do a whole lot of research to find out all the information I needed about these tax credits. After all that research, it turns out that I will not qualify for any of the credits because the credits for insulation, roofs, water heaters, heating and air conditioning, etc., are just one pool of money. This pool of money is limited to $1,500 per home, for tax years 2009 and 2010 together. In 2009, I had taken the full credit amount of $1,500 for replacement windows. So, whatever I do to my roof, I can't get any more tax credits since my $1,500 credit is already used up.

But, all hope was not lost yet. The government also offers a credit of up to 30% of cost for all solar panel, fuel cell, geothermal heat pump and wind turbine installations (cost of materials + cost of installation) with no upper limit on the tax credit that can be claimed for each home. This tax credit program runs until 2016. So, my contractor suggested a solar-powered attic vent fan. It would take the attic fan off the electric grid, saving me some money on my electric bill, and it would run the attic fan off solar energy. And I would be doing the environment a favor by switching something in the house to alternative energy.

Sounds like a good idea, and the right thing to do, right? And I thought so too. Without doing exhaustive research, I told the contractor to make it so. And then as an afterthought, I started doing the research I should have done earlier. Basically, attic ventilation is quite important to keep the attic from getting too hot and humid. If the attic, roof, and house are well-designed and your feng-shui is just so, then you can get away with not installing a powered attic vent fan at all. The external breezes are enough to keep the attic cool and dry.

Most houses don't have perfect feng-shui. Moreover, building codes do not care about feng-shui. So, most buildings, and the building code itself, do require powered attic vent fans to blow air through the attic and keep it from getting too hot and humid. The fans are linked to a thermostat so that they switch on when it gets above a certain temperature and switch off below that temperature. This is not only to make sure the fan does not operate when it is not needed, but also to save some energy because running the fan continuously is a sure-fire recipe for a fat electricity bill. The fan also lasts longer because it runs only when needed.

Now, solar-powered attic vent fans get around the problem by running directly off solar power. The fans are completely off the grid, so they never draw power from your house's wiring. Solar fans are usually standalone units that mount on the roof and require no wiring (and precious little maintenance) whatsoever. The solar panel generates electricity for the fan when the sun is shining on the panel, and there is not electricity supplied to the fan when the solar panel is in the dark (like at night). Only very high-end models have battery backups and advanced stuff like that. But since the attic gets hot only when the sun is shining on the roof, you only need the attic fan to operate when the sun is shining down on the solar panel and the solar panel is generating electricity. So far, so good.

The problem is that the fan runs whenever the solar panel gets sunlight and generates any electricity. It does not really matter what the temperature in the attic is. And here, the opinion is decidedly mixed as to whether this is a good thing or a bad thing. Some sites say this is a problem because you don't want the fan running in the middle of winter, sucking up warm air from the house and venting it out. This can obviously lead to higher heating bills. In fact, some sites claim that the increase in heating costs during winter can negate the lower costs during summer in places that have long, cold winters.

Other websites say that if your attic is well-insulated and there are no obvious ways for air from your house to get into the attic, it should not matter because the attic fan is just going to vent out cold air that is sucked in through the soffit vents. In fact, these websites claim that good ventilation is very important in the winter to prevent ice build-up on the roof during the winter, and in preventing a resultant "bad" thing called ice-damming, which can damage your roof.

I was quite torn by all this conflicting advice. My powered attic fan probably had a thermostat, and therefore, rarely kicked on during the winter. And my house and its roof did fine under those conditions. I don't want to change things by having the attic vent fan operate during the days in the winter and possibly increase my heating bills.

Now, many solar-powered attic fans do have what is called a thermal switch that limits when the fan operates. Even when the solar panel is generating electricity, if the thermal switch does not close, the fan gets no power, and therefore does not operate. And the thermal switch closes only when the temperature in the attic is above a certain point. This, I thought would be the ideal solution because I can take the fan off the grid in the summer, and still have it operating like it does right now in the winter (basically staying off all the time).

Today morning, when the contractor arrived and unloaded all the material for my roof replacement, I saw that the solar-powered attic fan he had bought was a model called Solar Star made by Solatube. I asked the contractor about the fan, but he admitted that this was the first time he was installing one, and he had no knowledge about them at all. We unpacked the box and found a single-piece solar panel hard-wired to a fan. When I turned the solar panel towards the sun, the fan started running.
Solar-powered attic vent fan
I asked the contractor about a thermal switch, and he had never heard of one! He knew that regular attic fans come with one, but he thought the only purpose of one was to save electricity. He was under the impression that if you could run the fan continuously without shelling out any money from your pocket, all the better! He did not know anything about the effects of continuous running on the durability of the fan or my heating bills.

Solatube's website does mention that all their attic fans come with an optional thermal switch. But optional is the operational term here. Unfortunately, we both searched all over the unit we had in our hands and could not locate anything remotely resembling a thermal switch. Not that we knew what a thermal switch would look like necessarily, but anything resembling a switch of some sort. Nothing. And the fan was running quite impressively even though I was holding the whole thing in my hand and the temperature was probably less than 70 degrees!

So, on my insistence, he got on the phone with his supplier and tried to get in touch with some person at the supplier who would know whether this model had a thermal switch or not. If it did not, I suggested he return this and get a model that did. And if it did, maybe someone would know how to set it.

Unfortunately, he is unable to get in touch with anyone who knows anything about these products. These products got a huge boost because of the government tax credit, and they started appearing en masse only late last year. Now, there are hundreds of companies putting them together, but nobody seems to know exactly how to use them, what their features are, what their advantages and disadvantages are, etc.

The rest of the roof installation is coming along fine, and the contractor needs to figure out whether to put up this fan or get a regular one before too long. I am still in two minds, and there are no experts to weigh in on this debate of whether a thermal switch is necessary or not. In fact, we don't even know whether this fan has one or not, leave alone whether it is needed or not!

I have to make a decision and tell my contractor one way or the other whether to go ahead with installing this. And if my contractor is so ignorant about these new-fangled devices, how do I trust him to even install it correctly so that it does what it is supposed to do? And will I even know if the thing does not do its job correctly? Or if it does its job too well and starts raising my heating bills through the roof (literally)? Who knew that something that sounded like such a no-brainer would end up hurting my brain so badly?!

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