Geo Innovations-worth getting excited about!

We’re excited to be part of this growing and innovative market-check out what’s new in Geo design!
Check out the LIMA-1 from the guys at Limnion corp. Yes! A Canadian company!

This technology revolutionizes the Pond Loop/Ocean Loop application.
Can’t wait to see what else they have in store.

Incentives-Geoexchange/Geothermal, Air Source and more!

Grants

There are grants available from both the Federal and Provincial governments for folks who take the initiative to upgrade the heating systems in their homes and who choose green energy options for their new builds. To learn more about these grants visit the ecoENERGY program (Federal) and the LiveSmart BC Program (Provincial).

To arrange a home energy audit contact Home Performance or CityGreen Solutions.

Manufacturers Incentives

With Carrier Cool Cash Consumers can receive up to a $1,200 rebate on a qualifying Carrier system or up to a $150 rebate on a Carrier unit.

Lending Institutions

Slowly but surely lending institutions are creating financing opportunities for those who make the commitment to lower their carbon footprints. Here are some of the front runners in the industry:
Toronto Dominion has developed the Renewable Energy Loans program. This program allows individuals to take advantage of up to a 15 year amortization on a fixed rate loan.

Check out this link to learn more about TD’s initiatives

For retrofit projects Vancity Savings Credit Union‘s Bright Ideas Loan works in unison with the ecoEnergy Retrofit program. This personal loan is at prime+1 rate¹ for up to ten years. The low interest rate saves you money compared to a conventional loan. You can borrow as little as $3,500 or a maximum of $20,000. Learn more…

C.C.E.C. Credit Union is participating in the Climate Smart initiative and has member  groups actively pursuing alternative lifestyle choices.  “We are pleased to offer retro-fit loans and other options to help our community groups and members lower their  carbon footprint.”  Arrange a meeting to find out if C.C.E.C. works for you!

Geothermal Retrofit

Q: Is it feasible to do a geothermal retrofit?

A: Sometimes it is…sometimes not.

If you’re gutting the house, a geo retrofit is as simple as a new installation. If you’re not, read on…

The primary goal is to reduce the load. This means upgrading windows and insulation first. These costs will translate into a significantly smaller geo system which will then pay for them and save more energy than geo alone. An unimproved house with a geo system will cause the geo system to be overloaded. Remember, the primary goal is to reduce the load.

The subject should then be broken down into 2 parts.
1) Do you have forced air heating with ductwork?
2) Do you have hot water heating with baseboards, radiators or radiant floors? This is called hydronic heating.

If you have forced air heating and it currently uses electricity or gas or oil, then generally the ductwork is too small and needs to be upgraded. The reason being is that the “dead dinosaur” burning furnace would deliver heat at 140 deg F and the new heat pump system would deliver only 100 deg F. (all approx values) This requires bigger ductwork to deliver the same amount of total heat. Simple, right?

An exception might be a really old house that had a big heating system designed for single pane glass and no insulation. If the glass and insulation were upgraded then the originally large ductwork would now be adequately sized. However this house would likely have been renovated at some point and the heating system could be inadequate or dysfunctional. If the basement is unfinished then ductwork upgrades are simpler than if the basement is fully finished, blocking access to the ductwork.

If you are replacing a tired air-source heat pump then the ductwork will likely be adequate.

If you have hydronic heating and it currently uses baseboard radiators that have copper tubes and aluminum fins (they’re not radiators at all, they’re convectors) then you’re out of luck unless you replace them and probably the distribution piping too.

If you have baseboard radiators that have cast-iron fins (rare) you may be in luck except you’d probably have to add more of them to make up for the previously mentioned lower output temperatures. If you have cast iron radiators (really old school) they may work but you may need to add more of them. They’ll need to be flushed and maybe some piping upgraded too.

If you have radiant floors, they are the easiest to convert, except some older floors (and still today) were/are badly designed and installed. They required high operating temps and were not that comfortable to begin with. If the radiant floors have enough tubing and loops installed the conversion should be relatively simple.

The 2 best parts of hydronic heating conversions is that you can rip out the mixing valve that used to mix down the high “dead dinosaur” burning boiler temps to what the radiant floor requires. You can also rip out the evil chimney and the CO detector. This was so inefficient due to the high temp standby losses in the mechanical room. Geo systems operate at low temps and have little or no standby losses.

The other best thing with hydronic heating conversions is that you can install outdoor reset control. http://www.tekmarcontrols.com/literature/acrobat/p022.pdf This is a further energy saving control that has been around for more than 40 years but only works on hydronic heating. At exchangenergy we install it on every hydronic system we design.

Summing up, geo retrofits can be feasible and even have a shorter payback than a new installation if you are replacing oil or propane as the fuel source. If your home meets the above criteria then a site visit is the next step.

Slinky Loops and the Laws of Physics

Q: I have limited yard space for a horizontal loop. I’ve seen “slinky” loops in photos. How do they work?

A: The premise that slinky loops will let you get more heat capacity from a smaller loop footprint is inherently flawed. When applying the laws of thermodynamics to ground loop design, it’s clear that there is a limited amount of energy available from a given amount of earth, and a limited amount of energy that the earth can absorb. Cramming in more pipe by using a slinky pit will have a number of ramifications:

1. In heating mode, the loops compete with each other for the same thermal energy, interfering with each others ability to do the intended work. This results in very low temperatures in the loops in the centre of the pit, and lower overall loop temperatures. This results in what we call the toilet effect. The loop temperatures start out OK, but spiral downwards until they are “flushed” and can’t recover. We’ve seen these loops running at 20F, abysmal performance. The earth is frozen and the moisture is crystallized, air pockets appear and the thermal conductivity nose dives. The system is forced to run on back-up heat, your operating costs go through the roof, and the high efficiency system you invested in becomes a black mark on our industry.
2. In cooling mode, the loop can’t dissipate the heat, so the loop heats up far above design temperatures. The slinky loop has hundreds of potential pinch points. When the pipe is softened by the high temps, and with 5 or 6 feet of earth on top of it, it tends to flatten at each pinch point, causing flow restrictions that decrease system performance even further. We use slinky loops in surface water loops (pond, lake, ocean), and in wet, swampy earth with high ground water flow. We don’t recommend this layout unless the conditions are ideally suited.

Q: So if I don’t use a slinky loop, what do I do now?

A: The tried and true horizontal loop system uses single straight pipe in trenches and requires way more space. Other established horizontal designs can use two, four, or six pipes in a trench. Each time you add a pair of pipes, your trench length per nominal ton of capacity goes down, but your pipe length and antifreeze volume goes up.
Another method is the “parking lot” loop – a pit loop using straight runs of pipe on 2’ centres. This will require a space typically more than twice the square footage of the building depending on the load and the ground conditions. If the loop field is large, temperatures in the centre may be low and impact the overall average temperature. This will be considered when GeoExchange experts are evaluating design options.
The ideal design for your property depends on the space available, the ground conditions, and the cost of the system making the system site specific – one of the things that makes GeoExchange so much fun and the reason we don’t get bored doing this over and over again!
If your lot doesn’t allow a properly designed horizontal loop, vertical boreholes are the order of the day: more upfront cost but well worth the investment.

Do-It-Yourself DIY Geothermal Projects

Q: Can I install a geothermal system myself? It doesn’t seem that complicated.

A: While it might not “seem” that complicated, Geoexchange / geothermal systems require multi-disciplinary skill sets and the most important part of the system is the design of it. A heat loss analysis of the building should be done. The thermal conductivity of the ground must be calculated or estimated from established data. The ground loop must be sized to meet the building heat load given the type of earth at the site. The flow rate pumped through the ground loop piping must be calculated to ensure effective heat transfer. The piping must be sized to minimize head pressure, pump size and pumping costs. The heat transfer fluid needs to be selected and quantity needs to be calculated. The ground loop must be flushed to ensure that no airlocks occur that can render sections of the loop ineffective, and to remove debris that could foul heat exchangers. The distribution system in the house must be designed to operate at system temperatures and take to maximize the potential efficiencies. Knowledge of control strategies and installation will also help maximize efficiency. Fusion welding of the piping requires experience and a ticket.
Manufacturers will not honour warranties if the system is not installed by a trained and qualified contractor. The system may require service or maintenance, who will perform that? Since the most important part of the system is buried underground, making repairs is near impossible.
If you’re a determined Do It Yourselfer go ahead and do other parts of homebuilding yourself. If you put in your own kitchen cabinets and don’t like them later they are easy to replace. You can even do your own framing since it will be inspected by people who know framing and corrections can be made in time.
For geo systems (and radiant floors too) please save yourself the grief and find a qualified designer and installer, check their references carefully and enjoy doing it yourself in a different part of your homebuilding.

Geothermal to Heat a Greenhouse

Q: I have a dry water well borehole that I’d like to use for geothermal / geoexchange to heat my greenhouse.

A: Your borehole can heat and cool a greenhouse of 1,000 to 2,000 sq ft depending on what temperatures you want to maintain. With the geothermal / geoexchange system you can keep the greenhouse mostly “closed”, meaning when it’s sunny, instead of opening the vents and dumping the precious heat, you will cool the plant zone instead and move the heat into the borehole. That night when you want to heat, the warmed borehole will return the day’s heat into the greenhouse. This is where you save lots of money because you’re using the day’s earlier solar gain instead of buying the heat energy from your favourite utility.

This system can be taken a giant step forward yet by changing the typical outdated heating methods to heating the plant zone instead of the whole space. You’ll need an air handler (a box with a fan and some coils in it) and some plastic ducting that will blow the conditioned air into the plant zone instead of the ceiling space. This will give you much improved plant yields and further energy savings. In essence you are abandoning the upper area of the greenhouse that is normally heated (uselessly) and you’re only heating/cooling/(de)humidifying the place that matters: the plant zone.

We can design and build the geothermal / geoexchange system for greenhouse heating in-house and we have partners who specialize in this new air handling technology.

Hoping this sheds some “warmth” on the subject!

Helpful Tip: Beware the Oversized Kitchen Exhaust Fan

Homeowners often select oversized kitchen exhaust fans not realizing that they require makeup air – adding considerably to the cost of their house project.

A sales representative may not even mention the “make-up air” issue at all and the the homeowner can subsequently experience some serious sticker-shock at the cost of make-up air.

For example a 600cfm fan requires 10kW of heat to temper the air.

This amount of makeup air represents the capacity of an entire electric furnace in a small home.

What Is A Geothermal System And How Does It Work?

GeoExchange systems are the most cost effective HVAC systems for buildings.  They have the lowest life-cycle costs and the smallest carbon footprint.  They recover solar energy stored in the earth and transfer in into buildings.  They can be also be used to cool buildings by transferring heat from the building to the earth.  Because the earth’s temperature is very stable, they operate at extremely high efficiencies.

Every day, the earth absorbs over half of the sun’s energy. GeoExchange (also known as or Earth Energy) systems rely primarily on this stored solar energy to heat or cool a building and provide domestic hot water.  Electricity provides the power required to extract heat from the earth.  For every kW of electricity used by a geo system, anywhere from 3 to 6 kW of heat energy are pulled from the earth.

The link with the earth is done in two basic ways: open loops and closed loops. In open loop systems, water is pumped from a well.  Issues here include water quality, water management, and sustainability.  Closed loop systems are most common, and are often preferred for their reliability and low maintenance.

Closed loops use a network of High Density Polyethylene (HDPE) pipes to transfer heat to and from the earth. The pipes can be inserted into vertical boreholes, buried in horizontal trenches, or submerged in the ocean, lakes, or rivers.

The magic in the system is the ground source heat pump, which concentrates heat from the earth and transfer it into a building. The system can be reversible to provide cooling.  This isn’t new technology; the first GeoExchange system was installed over 50 years ago!  A common example of a heat pump is a refrigerator, where heat is transferred from the inside of the fridge to the room through the black grill on the back.

By transferring thermal energy rather than creating it through combustion or electrical resistance, GeoExchange systems achieve very high efficiencies. For each unit of electrical energy consumed by a heat pump, three to four units of heat energy are moved from the earth to your building.

What Is The Average Cost Of Installation?

Installation costs are specific to each site and can start as low as $20,000 for an entry level system in a 2000 square ft. home.

Factors affecting installation costs include the heating and cooling load assessment, the usage of the system, the inclusion of domestic hot water or not, the type of distribution system used inside the building, and the thermal conductivity of the local soil.

We have included a link to a Canadian GeoExchange Coalition’s publication “The Buyers Guide to Residential Ground Source Heat Pump Systems” that we feel is a useful tool for those that are serious about working out the dollars and sense for themselves.

If you would like more information on your specific system contact us for a quote.

Bottom Line: What Is The Payback Period?

Some people just want to look at the numbers. Are you wondering how cost-effective a geothermal heating and cooling system would be for your project?

Below is a Canadian Geo Exchange publication that we feel is useful to those who want to evaluate both the energy and cost savings a Geo system will produce. The download includes a work sheet that will help you to figure out just how much it will cost you per month to heat your home using a variety of different fuels. If hitting the books isn’t your thing consider asking us to conduct a feasibility study on your project.

CGC Buyers Guide for Residential Ground source Heat Pump Systems

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