Time and costs change many good ideas into great ones

Monday, October 7, 2013

Some energy-saving techniques and devices pioneered decades ago are proving their worth in these more energy-conscious times

by RALPH WINFIELD

When I worked for Ontario Hydro in the late 1960s and early 1970s, I made many recommendations for environmental control in poultry and livestock buildings. Do remember that energy, including electrical energy, was relatively cheap in those days.

I remember very well trying to do a heat balance for temperature control in a cage layer building. It was very evident to me that the birds produced significantly more heat when they were active during the day than at night. Additional heat was needed to maintain building room temperature during the colder winter period.

So I contacted a good friend and former teaching/research colleague at Ridgetown College of Agricultural Technology, Don Luckham. Don's comments were very upfront. "Ralph, would you be prepared to sleep during the day and do your chores during the night?" Enough said. I did not recommend or promote the idea to any livestock or poultry producers in Ontario.

I recently received my regular copy of Today's Farmer, dated Tuesday, April 23, 2013. The lead story on the front page of the second section read, "Ontario egg farmer says her hens stay up all night." The story, written by Jeanine Moyer of Farm and Food Care Ontario, supports exactly the logical rationale that I concluded over 40 years ago! The only real change in those 40 years has been the cost of energy and the adaptability of dedicated egg producers, such as the Leeming family of Seaforth.

Last month, I had the opportunity to tour the new Upper Thames Conservation Authority Centre in London, which was designed to be a LEED building. (LEED is the acronym for Leadership in Energy and Environmental Design.) Was I impressed? You bet!

Interestingly enough, some of the major energy-saving techniques were refinements of ideas that were tested for livestock/poultry buildings back in the 1960s and '70s. The designers added building mass, using stone and concrete. Do you remember when most new swine barns were built using "sandwich concrete walls" to add thermal mass?

In the '60s and '70s, I also researched and field-tested solar walls on swine barns for Agriculture Canada in Ontario. We used the south walls as solar collectors with concrete block, opened top and bottom, to store the heat from daytime into nighttime. Did the concept work? Certainly it did. Plans were made available through the existing Canadian Farm Building Plan Service (CFBPS).

The Conservation Authority LEED building has dark-blue panels strategically placed on the south side of the building to temper the frosty incoming air during cold weather periods.

But wait. How many of you remember when research was conducted to temper incoming fresh air year-round using underground air tunnels with intake(s) remote from the building? Probably not too many of you do, because the concept was not used extensively in Ontario for livestock or poultry buildings. To make the concept work, the site had to be specially selected so the water table was not too high, because the tunnels had to be at least five or six feet below grade level. This was because of the site-specific requirements for tempering intake air using the earth's mass. We switched to open (curtained) side walls to let air flow through the livestock and poultry buildings without using any fan (electrical) energy.

Unfortunately, no true cooling effect was gained from the earth with this energy-saving technique, and it was used primarily for adult animals that did not require constant high temperatures.

There is no doubt in my mind that input energy for heating and ventilation can be saved in many ways for both human and livestock buildings. However, for the livestock sector, building design is driven totally by economics and siting can often be a limiter. For commercial buildings, the longer life cycle costing and variable site selection often give engineers and architects a wider range of opportunity.

We cannot leave this discussion without talking about water conservation. Water conservation techniques are everywhere but primarily in washrooms, where low-flow toilets are used. Unfortunately, we have not caught up to California yet. At the San Diego Zoo, they had no-flush, waterless, odourless urinals when I was there.

Tremendous improvements have been made in reduced-energy lighting fixtures for both human and livestock/poultry buildings. Natural lighting is used more often when improved windows are installed in buildings for human occupancy. In many poultry buildings, day length must be controlled. This means that natural lighting is not an option. But more energy-efficient fixtures are being used extensively in both human and livestock/poultry housing buildings.

Many of our older livestock barns in Ontario, where possible, used bank barns. The barn was set into an earthen bank so most of the livestock housing and root cellar only had small windows at the top. This setting also eliminated a separate barn bridge to get the threshing machine and loads of hay onto the barn floor.

In the 1970s, when energy usage became an issue, some rural homes were built into a bank with only a southern exposure to capture winter light and heat. They also featured green roofs, which are still being promoted today. The idea worked well but was very site-specific. This concept is not practical for urban subdivisions!

By the 1980s, we saw a great interest in and acceptance of ground-source heat pumps. This permitted the energy-efficient heat pumps to upgrade earth heat to a usable temperature for circulation in a residence. The idea caught on and is still being used very effectively in rural areas where the lots are larger and cheap natural gas is not available for space and water heating. Ground-source heat pumps can also be reversed to take building heat and put it back into the earth, thus also providing energy-efficient air conditioning.

With the price of energy increasing in all forms, but especially electrical energy, we must find and take advantage of opportunities to reduce usage or adjust use time when practical.

Conservation is and will be the most cost-effective. We can buy energy-efficient lighting units and appliances and use more time clocks and photocells. Transferring "no cost" heat from milk or earth can and should be next on the priority list. Heat pumps are very energy-efficient at transferring heat (their coefficient of performance or COP is over five, which means that at least five times as much energy is being acquired as compared to the electrical energy consumption).

I recently put a time clock on my electrical water heater. It turns on at 7 p.m. and off at 7 a.m. during weekdays and can be easily overridden on weekends and holidays so it utilizes only the cheaper off-peak power. Laundry is done after supper and the newer dishwasher has a four-hour delay feature, so dishes can be washed at night. BF

Agricultural engineer Ralph Winfield farms at Belmont in Elgin County.