When Tim Millard purchased Gimcrack Equestrian Centre in 2001 from EMG co-founder Robert Meilsoe, he wanted to make sure the equestrian centre on 40 acres in the rolling hills of King Township, ON, was run efficiently and in an environmentally-friendly manner so as not to negatively impact the challenged water table in the area. “There were lots of issues there,” he admitted. “They used to just throw the manure over the side of the hill. I could see from Google Earth images the plume of effluent coming out of the manure pile, making a black trail toward the pond. It was after the Walkerton water crisis and I thought ‘This is a disaster waiting to happen.’”
Millard set about containing the manure that the farm’s population of 35-40 horses were producing. “I decided to build a manure containment box out of concrete blocks. But I couldn’t believe the amount of heat that was coming off that thing. You can’t even stick your hand in the manure pile up to your elbow, because it will burn your knuckles! I had to harvest that.
“We have radiant floor heating at home and it works wonderfully. I figured if you can conduct heat by pumping water with a boiler and radiate it into a concrete floor, and the heat from the floor radiates into the room – it should work the opposite way. If you put a pile of hot manure on top of a concrete slab and it heats the concrete up, and the concrete has water tubes weaving back and forth in it, it should heat the water up. If you pump that water through a radiator in the arena, you should be able to heat the arena.”
The water pipes running back to the barn are buried below the frost line and covered with inexpensive pool noodles, which are slit, wrapped around the pipe, and secured with duct tape. Variable speed pumps regulate the water speed. “If you let the water run too fast, it will return to the arena before it’s garnered enough heat from the manure,” explains Millard. “If it flows too slowly, you’re not extracting it as fast as you could.” He found the best volume for his pumps worked out to eight gallons per minute to achieve the highest temperature coming in (110º F/43ºC) and the lowest possible temperature going back to the manure pile (55º F/13ºC) – a 55-degree (30ºC) temperature spread. The system works beautifully – so well, in fact, that in the warmer months when the radiators are not being used in the arena, it provides hot water in the barns.
One would assume that Millard is an engineer; “I’m just an inventer,” says the chartered accountant whose motivation is “There must be a better way.” Other projects he has developed include a manure incinerator and a smokeless air curtain burner for incinerating tree stumps.
He admits that if he had to do it over again, he would incorporate some changes to make the system even more efficient. “I would have used bigger tubing – 1” instead of 3/4” – and I would have used more of it. [He did not install tubing under one end of the concrete slab, because he thought it would never get that full of manure. It does.] The other thing is that I should have done it in two zones; I should have divided the box into two halves and have one zone heat the west side of the arena and the other zone heat the east side of the arena.” Right now, with just one heater in the east end, the west end tends to be cold.
In the coldest part of the winter the propane heaters still need to fire up, but it doesn’t take as long to get the arena up to a comfortable temperature. “We figure from the time we implemented it, it’s saving us over $1,000 a month in propane.”
So what did this sytem cost overall? “It wasn’t very much, because I did a lot of it myself – probably about $13,000-$15,000. But there are grants, so at the end of the day it never cost me a dime,” says Millard. “I got an OMAFRA Smart Farm Program grant which covered 30 per cent of what it I spent. Then I made an application for an incentive called Scientific Research and Experimental Development (SR&ED), because it was research – nobody had ever done this before. They loved it, so they gave me the remainder of my money back. Then I actually got a bursary of $2,000 for Green Initiatives from the province of Ontario, because instead of burning propane in the arena, we are getting free heat from the manure pile.”
Millard suggests that anyone wanting to do this themselves could possibly modify the system slightly and still qualify for a SR&ED tax incentive. “I could patent it, but I feel strongly that everyone should be able to do this.”