EcoRenovator - View Single Post - Need some help conceptualizing a reduced cost water heater solution for rentals

Zooomer · 07-16-18, 04:44 PM

Thanks for the reply.

I have many rentals and I've gone over solutions and dealt with problems for a decade.

Over the weekend I had DTE change a gas meter, when they turned the gas back on, the water heater didn't turn back on. (70% gas style). So I log this as an issue. Rare, but still a potential fail point.

The idea is to reduce maintenance and failure of all kinds. Rentals are really a numbers game so it's a math equation at some point.

When rehabbing an old house, I have never been able to vent outside along the side of the house unless it had a side mounted chimney. Installation costs and permitting is high on a gas unit. They make you do a leak down test for 24 hours and charge you additional $ if you disturb the gas line.

Almost all landlords and many new constructions are going with resistive electric because the install and purchase price are much lower, plus you don't have a vent issue. The only real downside is higher cost to tenant and unfortunately most landlords are too short sighted to care. Not to mention tenants don't shop based on that because they don't know.

If you have a system of any sort that includes a passive storage you can raise the temp of water in the winter ~25 deg and summer 10-15. Assuming a hot water tank at 125 you'll increase hot capacity and reduce any bill by up to 30%. Totally passively with zero maintenance and low cost.
Typical electric costs about $50/month, gas 1/3 of that (depending on use of course).
You could combine passive storage with another solution.

An AC coil is far more restrictive than what I'm proposing and doesn't cause issue so restricted airflow is not a consideration. A new furnace heats at 96% efficiency so 'preheating' the water is going to be more cost effective than any solution out there. Should be no maintenance either. Just have to decide whether to run the fan or just let it happen.

Rentals is a side business for me. Primary business has manufacturing setup so I would run any idea at scale. Either in house or with an existing partner.

---15 years ago I built a crude heat recovery unit for my shower. I got 10 deg rise in about 30". Was a poor design. Since them I've considered a double wall cast P trap with recovery built in. Kind of more of a new construction thing tho.

07-16-18, 04:44 PM	#5
Zooomer Lurking Renovator Join Date: Aug 2014 Location: Grand Rapids MI Posts: 12 Thanks: 0 Thanked 2 Times in 1 Post	Thanks for the reply. I have many rentals and I've gone over solutions and dealt with problems for a decade. Over the weekend I had DTE change a gas meter, when they turned the gas back on, the water heater didn't turn back on. (70% gas style). So I log this as an issue. Rare, but still a potential fail point. The idea is to reduce maintenance and failure of all kinds. Rentals are really a numbers game so it's a math equation at some point. When rehabbing an old house, I have never been able to vent outside along the side of the house unless it had a side mounted chimney. Installation costs and permitting is high on a gas unit. They make you do a leak down test for 24 hours and charge you additional $ if you disturb the gas line. Almost all landlords and many new constructions are going with resistive electric because the install and purchase price are much lower, plus you don't have a vent issue. The only real downside is higher cost to tenant and unfortunately most landlords are too short sighted to care. Not to mention tenants don't shop based on that because they don't know. If you have a system of any sort that includes a passive storage you can raise the temp of water in the winter ~25 deg and summer 10-15. Assuming a hot water tank at 125 you'll increase hot capacity and reduce any bill by up to 30%. Totally passively with zero maintenance and low cost. Typical electric costs about $50/month, gas 1/3 of that (depending on use of course). You could combine passive storage with another solution. An AC coil is far more restrictive than what I'm proposing and doesn't cause issue so restricted airflow is not a consideration. A new furnace heats at 96% efficiency so 'preheating' the water is going to be more cost effective than any solution out there. Should be no maintenance either. Just have to decide whether to run the fan or just let it happen. Rentals is a side business for me. Primary business has manufacturing setup so I would run any idea at scale. Either in house or with an existing partner. ---15 years ago I built a crude heat recovery unit for my shower. I got 10 deg rise in about 30". Was a poor design. Since them I've considered a double wall cast P trap with recovery built in. Kind of more of a new construction thing tho.